Thursday, November 6, 2008

Fastest Land Animals

Animal Speed (miles per hour)
1-/ Cheetah 70
2-/ Pronghorn Antelope 61
3-/ Wildebeest 50
4-/ Lion 50
5-/ Thomson's Gazelle 50
6-/ Quarter Horse 47.5
7-/ Elk 45
8-/ Cape Hunting Dog 45
9-/ Coyote 43
10-/ Gray Fox 42
11-/ Hyena 40
12-/ Zebra 40
13-/ Mongolian Wild Ass 40
14-/ Greyhound 39.35
15-/ Whippet 35.5
16-/ Rabbit (domestic) 35
17-/ Mule Deer 35
18-/ Jackal 35
19-/ Reindeer 32
20-/ Giraffe 32
21-/ White-Tailed Deer 30
22-/ Warthog 30
23-/ Grizzly Bear 30
24-/ Cat (domestic) 30
25-/ Human 27.89
26-/ Elephant 25
27-/ Black Mamba Snake 20
28-/ Six-Lined Racerunner 18
29-/ Wild Turkey 15
30-/ Squirrel 12
31-/ Pig (domestic) 11
32-/ Chicken 9
33-/ Spider (Tegenaria atrica) 1.17
34-/ Giant Tortoise 0.17
35-/ Three-Toed Sloth 0.15
36-/ Garden Snail 0.03

Cheetah

The cheetah is the world's fastest land mammal. With acceleration that would leave most automobiles in the dust, a cheetah can go from 0 to 60 miles (96 kilometers) an hour in only three seconds. These big cats are quite nimble at high speed and can make quick and sudden turns in pursuit of prey.Before unleashing their speed, cheetahs use exceptionally keen eyesight to scan their grassland environment for signs of prey—especially antelope and hares. This big cat is a daylight hunter that benefits from stealthy movement and a distinctive spotted coat that allows it to blend easily into high, dry grasses.When the moment is right a cheetah will sprint after its quarry and attempt to knock it down. Such chases cost the hunter a tremendous amount of energy and are usually over in less than a minute. If successful, the cheetah will often drag its kill to a shady hiding place to

Pronghorns

Fleet-footed pronghorns are among the speediest animals in North America. They can run at more than 53 miles (86 kilometers) an hour, leaving pursuing coyotes and bobcats in the dust. Pronghorns are also great distance runners that can travel for miles at half that speed.Pronghorns are about three feet (one meter) tall at the shoulders. They are reddish brown, but feature white stomachs and wide, white stripes on their throats. When startled they raise the hair on their rumps to display a white warning patch that can be seen for miles.Both sexes sport impressive, backward-curving horns. The horns split to form forward-pointing prongs that give the species its name. Some animals have horns that are more than a foot (30 centimeters) long.Like other even-toed hoofed animals, pronghorns chew cud—their own partially digested food. The meal of choice for this speedy herbivore is generally grass, sagebrush, and other vegetation.Pronghorns mate each fall in the dry, open lands of western North America. Bucks gather harems of females and protect them jealously—sometimes battling rivals in spectacular and dangerous fights. In the spring, females


Wildebeest

The ungainly gnu earned the Afrikaans name wildebeest, or "wild beast," for the menacing appearance presented by its large head, shaggy mane, pointed beard, and sharp, curved horns. In fact, the wildebeest is better described as a reliable source of food for the truly menacing predators of the African savanna: lions, cheetahs, wild dogs, and hyenas.The gnu (pronounced "g-new" or simply "new") is a member of the antelope family, although its heavy build and disproportionately large forequarters make it look more bovine. Gnus can reach 8 feet (2.4 meters) in length, stand 4.5 feet (1.4 meters) tall at the shoulders and weigh up to 600 pounds (272 kilograms). Both males and females grow horns.Their habitat comprises the grassy plains and open woodlands of central, southern, and eastern Africa, particularly the Serengeti in Tanzania and Kenya. They travel in large herds and are active day and night, grazing constantly.Their spectacular northward migration in search of greener pastures is dictated by weather patterns, but usually takes place in May or June. It is considered one of the greatest wildlife spectacles on Earth, involving up to 1.5 million wildebeests as well as hundreds of thousands of other animals, including zebra and gazelle.Up to 500,000 calves are born in February and March each year, at the beginning of the rainy season. Calves learn to walk within minutes of birth and within days are able to keep up with the heard. Gnus can live to be 20 years old.

African Lion

Lions are the only cats that live in groups, which are called prides. Prides are family units that may include up to three males, a dozen or so females, and their young. All of a pride's lionesses are related, and female cubs typically stay with the group as they age. Young males eventually leave and establish their own prides by taking over a group headed by another male.Only male lions boast manes, the impressive fringe of long hair that encircles their heads. Males defend the pride's territory, which may include some 100 square miles (259 square kilometers) of grasslands, scrub, or open woodlands. These intimidating animals mark the area with urine, roar menacingly to warn intruders, and chase off animals that encroach on their turf.Female lions are the pride's primary hunters. They often work together to prey upon antelopes, zebras, wildebeest, and other large animals of the open grasslands. Many of these animals are faster than lions, so teamwork pays off.After the hunt, the group effort often degenerates to squabbling over the sharing of the kill, with cubs at the bottom of the pecking order. Young lions do not help to hunt until they are about a year old. Lions will hunt alone if the opportunity presents itself, and they also steal kills from hyenas or wild dogs.Lions have been celebrated throughout history for their courage and strength. They once roamed most of Africa and parts of Asia and Europe. Today they are found only in parts of sub-Saharan Africa, except for one very small population of Asian lions that survives in India's Gir Forest.

Thomson's Gazelle

Gazelles are medium-sized antelopes found in Africa and in Asia as far east as Mongolia. There are some 19 different species of gazelles.These grazing antelopes live in herds, which can consist of as few as ten or as many as several hundred animals. During the plentiful rainy season, thousands of animals can be seen gathering in large groups.Gazelles typically frequent wide-open spaces and plains, where they browse on grasses, shoots, and leaves.Open plains make them visible to predators like cheetahs or wild dogs, but gazelles are fleet of foot. The Thomson's gazelle can reach speeds of 40 miles (64 kilometers) an hour.Some gazelle species eschew the grasslands for mountainous landscapes or even deserts. During the dry season some grassland gazelles will even take to the African bush in search of water.Gazelles are nimble and beautiful animals, with a variety of stripes and markings that accentuate their tan buff coats and white rumps. They also boast a impressive, ringed horns. These attributes make many gazelles attractive as game animals.After a pregnancy of about six months, female gazelles give birth to one or two young and hide them in the plains grasses. These infants will remain out of sight for days or even weeks, being periodically nursed by their mother, until they are old enough to join the mother's herd, in the case of females, or a bachelor herd.

American Quarter Horse

The American Quarter Horse is an American breed of horse that excels at sprinting short distances. Its name came from its ability to outdistance other breeds of horse in races of a quarter mile or less, where some individuals have been clocked at speeds up to 55 mph. The American Quarter Horse is the most popular breed in the United States today, and the American Quarter Horse Association is the largest breed registry in the world, with over 3 million American Quarter Horses registered worldwide.

The American Quarter Horse is well known both as a race horse and for its performance in rodeos, horse shows and as a working ranch horse. The compact body of the American Quarter Horse is well-suited to the intricate and speedy maneuvers required in reining, cutting, working cow horse, barrel racing, calf roping, and other western riding events, especially those involving live cattle. The American Quarter Horse is also shown in English disciplines, driving, and many other equestrian activities.


Elk

Elk are also called wapiti, a Native American word that means "light-colored deer." Elk are related to deer but are much larger than most of their relatives. A bull (male) elk's antlers may reach 4 feet (1.2 meters) above its head, so that the animal towers 9 feet (2.7 meters) tall.Bull elk lose their antlers each March, but they begin to grow them back in May in preparation for the late-summer breeding season.In early summer, elk migrate to high mountain grazing grounds where the cows (females) will give birth. Each cow typically has a single calf, which can stand by the time it is 20 minutes old.During the late summer breeding season the bugling of bull elk echoes through the mountains. These powerful animals strip the velvet off their new antlers using them in violent clashes that determine who gets to mate with whom. Males with the bigger antlers, typically older animals, usually win these battles and dominate small herds.In the winter, wapiti reconvene into larger herds, though males and females typically remain separate. The herds return to lower valley pastures where elk spend the season pawing through snow to browse on grass or settling for shrubs that stand clear of the snow cover.Elk were once found across much of North America but they were killed off and driven to take refuge in more remote locations. Today they live primarily in western North America, especially in mountainous landscapes such as Wyoming's National Elk Refuge and Yellowstone National Park. Some eastern U.S. states have reintroduced small elk herds into heavily wooded wilderness areas.

African Wild Dog

The African wild dog, also called Cape hunting dog or painted dog, typically roams the open plains and sparse woodlands of sub-Saharan Africa.These long-legged canines have only four toes per foot, unlike other dogs, which have five toes on their forefeet. The dog's Latin name means "painted wolf," referring to the animal's irregular, mottled coat, which features patches of red, black, brown, white, and yellow fur. Each animal has its own unique coat pattern, and all have big, rounded ears.African wild dogs live in packs that are usually dominated by a monogamous breeding pair. The female has a litter of 2 to 20 pups, which are cared for by the entire pack. These dogs are very social, and packs have been known to share food and to assist weak or ill members. Social interactions are common, and the dogs communicate by touch, actions, and vocalizations.African wild dogs hunt in formidable, cooperative packs of 6 to 20 (or more) animals. Larger packs were more common before the dogs became endangered. Packs hunt antelopes and will also tackle much larger prey, such as wildebeests, particularly if their quarry is ill or injured. The dogs supplement their diet with rodents and birds. As human settlements expand, the dogs have sometimes developed a taste for livestock, though significant damage is rare. Unfortunately, they are often hunted and killed by farmers who fear for their domestic animals.African hunting dogs are endangered. They are faced with shrinking room to roam in their African home. They are also quite susceptible to diseases spread by domestic animals.

Coyote

The coyote appears often in the tales and traditions of Native Americans—usually as a very savvy and clever beast. Modern coyotes have displayed their cleverness by adapting to the changing American landscape. These members of the dog family once lived primarily in open prairies and deserts, but now roam the continent's forests and mountains. They have even colonized cities like Los Angeles, and are now found over most of North America. Coyote populations are likely at an all-time high.These adaptable animals will eat almost anything. They hunt rabbits, rodents, fish, frogs, and even deer. They also happily dine on insects, snakes, fruit, grass, and carrion. Because they sometimes kill lambs, calves, or other livestock, as well as pets, many ranchers and farmers regard them as destructive pests.Coyotes are formidable in the field where they enjoy keen vision and a strong sense of smell. They can run up to 40 miles (64 kilometers) an hour. In the fall and winter, they form packs for more effective hunting.Coyotes form strong family groups. In spring, females den and give birth to litters of three to twelve pups. Both parents feed and protect their young and their territory. The pups are able to hunt on their own by the following fall.Coyotes are smaller than wolves and are sometimes called prairie wolves or brush wolves. They communicate with a distinctive call, which at night often develops into a raucous canine chorus.

Gray Fox - Urocyon cinereoargenteus


Characteristics
The gray fox is a peppery gray on top, reddish-brown on its sides, chest and the back of its head. Its legs and feet are also a reddish color. It has a long bushy tail with a black stripe on top. The gray fox has pointed ears, a pointed muzzle and long hooked claws.

Range
The gray fox can be found from southern Canada to northern Columbia and Venezuela. It is not found in some mountainous parts of the Northwest United States and in the Great Plains.

Habitat
The gray fox lives in a wide variety of habitats but prefers areas with lots of brush or woods.

Diet
The gray fox is a solitary hunter and eats a wide-variety of foods. A large part of its diet is made up of small mammals like mice, voles and eastern cottontail rabbits. It also eats birds; insects; and plants like corn, apples, nuts, berries and grass. In the summer and autumn, grasshoppers and crickets are an important part of its diet.

Life Cycle
Mating season is between January and April. About 53 days after mating, the female gives birth to one to seven pups. The male helps feed the pups. They are weaned when they are about three months old and are able to hunt on their own when they are four months old. The pups leave their mother in the autumn. The same males and females usually mate together every year.

Behavior
The gray fox can climb and will occasionally forage for food or rest in a tree. It makes its den in rocky crevices, caves, hollow logs and trees. It will sometimes enlarge a woodchuck burrow and use it as a den. Dens are usually used only during the mating season and when raising young.

Spotted Hyena

Spotted hyenas are famed scavengers and often dine on the leftovers of other predators. But these hardy beasts are also skilled hunters that will take down wildebeest or antelope. They also kill and eat birds, lizards, snakes, and insects.In an increasingly overpopulated Africa, hyenas and humans come into frequent contact. In fact, the Maasai people of Kenya and Tanzania actually leave their dead to be consumed by hyenas. However, these intelligent and bold animals will raid food stores and crops and are blamed for many livestock and even some human deaths. In some areas they have been heavily hunted as destructive pests.Spotted hyenas are the largest of three hyena species. Brown and striped hyenas are the other two. Although hyenas appear similar to dogs, they are actually more closely related to cats. They live throughout much of Africa and eastwards through Arabia to India. Spotted hyenas live together in large groups called clans that may include up 80 individuals and are led by females.Spotted hyenas have good hearing and sharp eyesight at night. They are fast and can run for long distances without tiring. Packs work together effectively to isolate a herd animal, sometimes one that is ill or infirm, and pursue it to the death. The victors often squabble over the spoils, either among themselves or with other powerful animals like lions.Spotted hyenas are quite vocal and make a wide variety of sounds, including the "laughing" that has long been associated with their name.

Zebra

No animal has a more distinctive coat than the zebra. Each animal's stripes are as unique as fingerprints—no two are exactly alike—although each of the three species has its own general pattern.Why do zebras have stripes at all? Scientists aren't sure, but many theories center on their utility as some form of camouflage. The patterns may make it difficult for predators to identify a single animal from a running herd and distort distance at dawn and dusk. Or they may dissuade insects that recognize only large areas of single-colored fur or act as a kind of natural sunscreen. Because of their uniqueness, stripes may also help zebras recognize one another.Zebras are social animals that spend time in herds. They graze together, primarily on grass, and even groom one another.Plains (Burchell's) zebras are the most common species. They live in small family groups consisting of a male (stallion), several females, and their young. These units may combine with others to form awe-inspiring herds thousands of head strong, but family members will remain close within the herd.Zebras must be constantly wary of lions and hyenas. A herd has many eyes alert to danger. If an animal is attacked, its family will come to its defense, circling the wounded zebra and attempting to drive off predators.

Mongolian Wild Ass

The Mongolian Wild Ass (Equus hemionus hemionus, also called Khulan) is a subspecies of the Onager. It may be synonymous with the Gobi Kulan or Dziggetai (Equus hemionus luteus).[1] It is found in Mongolia and northern China, and was previously found in Kazakhstan before it became extinct due to hunting.[2]

The Mongolian Wild Ass's distribution range was dramatically reduced during the 1990s. A 1994-1997 survey estimated its population size at 33,000 to 63,000 individuals over a continuous distribution range encompassing all of southern Mongolia.[3] In 2003, a new survey found approximately 20,000 individuals over an area of 177,563 km² in southern Mongolia.[4] The population estimates of the Mongolia population should be treated with caution due to a lack of proven survey protocols.[5][6] Despite that, the subspecies lost about 50% of its former distribution range in Mongolia in the past 70 years.

The population is declining due to poaching and competition from grazing livestock and the conservation status of the species is evaluated as vulnerable.[1] Since 1953, the Mongolian Wild Ass has been fully protected in Mongolia. The subspecies is also listed at appendix I of the Convention on the International Trade in Endangered Species (CITES) and was added to appendix II of the Convention of Migratory Species in 2002.[7] However, due to human population growth in conjunction with severe winters in the past years,[8] the number of conflicts between herders and Mongolian Wild Ass's appear on the increase.

Poaching for meat appears to be an increasing problem in Mongolia. For some parts of the local population, wild ass and other wildlife meat seems to provide a substitute or even a cheap alternative to meat from domestic animals.[9] In 2005, a national survey based on questionnaires, suggested that as many as 4,500 wild asses, about 20% of the whole population, may be poached each year.[10] Moreover, political changes in the early 1990s allowed urban populations to return to nomadic land use, resulting in a sharp increase in human- and livestock numbers in many rural areas.[11][12][13]

Political and socital changes have disrupted traditional land use patterns, weakened law enforcement and also changed attitudes towards the use of natural resources, e.g. making wildlife an "open access" resource.[14] It is expected that the remigration of people and their livestock will result in increased wildlife-human interactions and may well threaten the survival of rare wildlife species in the Gobi Desert.

Greyhound

The Greyhound is a breed of dog that has been primarily bred for coursing game and racing, but with a recent resurgence of popularity as a family pet. It is a soft and intelligent breed that often becomes attached to its owners. It is the fastest breed of dog on the planet [1]. A combination of long, powerful legs, deep chest and aerodynamic build allows it to reach speeds of up to 72 km/h (45 mph) in less than one and a half seconds, or within 3 strides.

Appearance
Males are usually 71 to 76 cm (28 to 30 inches) tall at the withers and weigh around 27 to 40 kg (70 to 100 pounds). Females tend to be smaller with shoulder heights ranging from 68 to 71 cm (27 to 28 inches) and weights from less than 27 to 34 kg (60 to 75 pounds). Greyhounds have very short hair, which is easy to maintain. There are approximately thirty recognized color forms, of which variations of white, brindle, fawn, black, red and blue (gray) can appear uniquely or in combination.[2]

Temperament
A male brindle Greyhound

Although Greyhounds are extremely fast and athletic, and despite their reputation as racing dogs, they are not high-energy dogs. They are sprinters, and although they love running, they do not require extensive exercise. Most are quiet, gentle animals. An adult Greyhound will stay healthy and happy with a daily walk of as little as 20 to 30 minutes. Greyhounds have been referred to as "Forty-five mile per hour couch potatoes."[3]

Racing
Main article: Greyhound racing
Until the early twentieth century, Greyhounds were principally bred and trained for coursing. During the early 1920s, modern Greyhound racing was introduced into the United States and introduced into United Kingdom (Belle Vue) in 1936 and Northern Ireland (Celtic Park) on April 18th 1927 and immediately followed by Shelbourne Park in Dublin very soon after.[citation needed] The Greyhound holds the record for fastest recorded dog.

Greyhounds as pets
Greyhound owners and adoption groups generally consider Greyhounds to be wonderful pets.[4] They are pack-oriented dogs, which means that they will quickly adopt humans into their pack as alpha. They can get along well with children, dogs and other family pets.[5] Rescued racing Greyhounds occasionally develop separation anxiety when re-housed or when their new owners have to leave them alone for a period of time (the addition of a second greyhound often solves this problem).[6]

An adopted Greyhound, 5 years old
Greyhounds bark very little, which helps in suburban environments, and are usually as friendly to strangers as they are with their own family.[7] The most common misconception concerning Greyhounds is that they are hyperactive. In retired racing Greyhounds it is usually the opposite. Young Greyhounds that have never been taught how to utilize the energy they are bred with, can be hyperactive and destructive if not given an outlet, and require more experienced handlers.[citation needed]

Greyhound Adoption groups generally require owners to keep their Greyhounds on-leash at all times, except in fully enclosed areas.[8][9][10][11][12][13][14][15] This is due to their prey-drive, their speed, and the assertion that Greyhounds have no road sense.[16] Due to their strength, adoption groups recommend that fences be between 4 and 6 feet, to prevent them being able to jump.[8]

Greyhounds do shed but do not have undercoats and therefore are less likely to trigger people's dog allergies (Greyhounds are sometimes incorrectly referred to as "hypoallergenic"). The lack of an undercoat, coupled with a general lack of body fat, also makes Greyhounds more susceptible to extreme temperatures, and most sources recommend that Greyhounds be housed inside.[17]

Greyhounds are very sensitive to insecticides.[18] Many vets do not recommend the use of flea collars or flea spray on Greyhounds unless it is a pyrethrin-based product. Products like Advantage, Frontline, Lufenuron, and Amitraz are safe for use on Greyhounds and are very effective in controlling fleas and ticks. [19]

It is often believed that Greyhounds need a large living space, however, they can thrive in small spaces. Due to their temperament, Greyhounds can make better "apartment dogs" than some of the smaller hyperactive breeds[citation needed].

Welfare

Greyhound racing
In the late 20th century several Greyhound adoption groups were formed. The early groups were formed in large part out of a sense of concern about the treatment of the dogs while living on the track. These groups began taking greyhounds from the racetracks when they could no longer compete and placing them in adoptive homes.[citation needed] Prior to the formation of these groups, in the United States over 20,000 retired Greyhounds a year were euthanized; recent estimates still number in the thousands, with about 90% of National Greyhound Association-registered animals either being adopted, or returned for breeding purposes (according to the industry numbers upwards of 2000 dogs are still killed annually in the US while anti-racing groups estimate the figure at closer to 12,000.).[20]

Accidents and disease are also common killers among racing Greyhounds. In 2005, an epidemic of respiratory failure killed dozens of dogs and left over 1200 quarantined in the U.S., particularly in Massachusetts, Colorado, Iowa and Rhode Island[citation needed].

The vast majority of Greyhounds in the USA are bred for racing (registered with the National Greyhound Association or NGA), leading American Kennel Club registered dogs about 150:1[citation needed]. Each NGA dog is issued a Bertillon card, which measures 56 distinct identifying traits with the Bertillon number tattooed on the dog's ear to prove identity during their racing career.[citation needed]

Not all dogs bred for racing are able to do so, due to speed, temperament, or physical problems. Most NGA greyhounds finish racing between two and five years of age. Some retired racing greyhounds have injuries that may follow them for the remainder of their lives, although the majority are healthy and can live long lives after their racing careers are over.[citation needed]
There are currently two online databases to easily lookup or search for all past and present registered dogs: Greyhound-Data.com and Rosnet2000.com Dogs can be searched by their Bertillon number, race name, and other attributes. Data includes dog photos, race statistics, and pedigree.

Health
Greyhound running
Greyhounds are typically a healthy and long-lived breed, and hereditary illness is rare. Some Greyhounds have been known to develop esophageal achalasia, Bloat (gastric torsion), and osteosarcoma. Because the Greyhound's lean physique makes it ill-suited to sleeping on hard surfaces, owners of companion Greyhounds generally provide soft bedding; without bedding, Greyhounds are prone to develop painful skin sores. Greyhounds typically live 10–13 years.[21]
Due to the unique physiology and anatomy of greyhounds, a veterinarian who understands the issues relevant to the breed is generally needed when the dogs need treatment, particularly when anaesthesia is required. Greyhounds cannot metabolize barbiturate-based anesthesia as other breeds can because they have lower amounts of oxidative enzymes in their livers.[22] Greyhounds demonstrate unusual blood chemistry, which can be misread by veterinarians not familiar with the breed; this can result in an incorrect diagnosis.

Greyhounds have higher levels of red blood cells than other breeds. Since red blood cells carry oxygen to the muscles, this higher level allows the hound to move larger quantities of oxygen faster from the lungs to the muscles.[23] Greyhounds have lower levels of platelets than other breeds. Veterinary blood services often use Greyhounds as universal blood donors.[24].
Gastric torsion can occur which causes the stomach to twist, heavy vomiting, pain and death within a few hours if not treated with surgery. This condition is common to many deep chested dogs.

History
Sighthounds unleashed in Paolo Uccello's Night hunt (Ashmolean Museum)
Popularly, the breed's origin can be traced to ancient Egypt, where a bas-relief depicting a smooth-coated Saluki (Persian Greyhound) or Sloughi was found in a tomb built in 4000 BC. Analyses of DNA reported in 2004, however, suggest that the Greyhound is not closely related to these breeds, but is a close relative to herding dogs.[25][26]

Historically, these sighthounds were used primarily for hunting in the open where their keen eyesight is valuable. It is believed that they (or at least similarly-named dogs) were introduced to the area now known as the United Kingdom in the 5th and 6th century BC from Celtic mainland Europe although the Picts and other hunter gatherer tribes of the Northern area (now known as Scotland) were believed to have had large hounds similar to that of the Deerhound before the 6th century BC.[citation needed]

The name "Greyhound" is generally believed to come from the Old English grighund. "Hund" is the antecedent of the modern "hound", but the meaning of "grig" is undetermined, other than in reference to dogs in Old English and Norse. Its origin does not appear to have any common root with the modern word "grey" for colour, and indeed the Greyhound is seen with a wide variety of coats.[citation needed] This may be confusing, however, as the Deerhound and Irish wolfhound are more commonly grey in colour and possibly the true origins of the Greyhound.[citation needed] However, the Deerhound and Irish wolfhound, the latter being a reconstructed breed, probably cannot have had any genetic influence on the much older Greyhound. It is known that in England during the medieval period, Lords and Royalty keen to own Greyhounds for sport, requested they be bred to colour variants that made them easier to view and identify in pursuit of their quarry.[citation needed] The lighter colours, patch-like markings and white appeared in the breed that was once ordinarily grey in colour. The Greyhound is the only dog mentioned by name in the Bible; the King James version names the Greyhound as one of the Four things stately in the Proverbs.[27] However, in the modern version of the Bible this has been changed to strutting rooster, which appears to be a more correct translation of the Hebrew term זַרְזִיר (zarzir).

According to Pokorny[28] the English name "greyhound" does not mean "gray dog/hound", but simply "fair dog". Subsequent words have been derived from the Proto-Indo-European root *g'her- 'shine, twinkle': English gray, Old High German gris 'grey, old', Old Icelandic griss 'piglet, pig', Old Icelandic gryja 'to dawn', gryjandi 'morning twilight', Old Irish grian 'sun', Old Church Slavonic zorja 'morning twilight, brightness'. The common sense of these words is 'to shine; bright'.

Whippet


The Whippet is a breed of dog, specifically a member of the sighthound family. They are active and playful and are physically similar to a small greyhound. Their popularity has led to the reuse of the Whippet name on a large number of things, from cars to cookies.


Appearance
Whippets are a medium-size dog averaging in weight from 25 to 40 lb (11–18 kg), with height (under the FCI standard) of 18.5 inches (47 cm) for dogs and 17.5 inches (44 cm) for bitches. Whippets tend to be somewhat larger in the United States with their population in show, coursing and some race Whippets required to be within the AKC standard of 18.5 to 22.5 inches (48–56 cm) for dogs, and 17.5 to 21.5 inches (46–53 cm) for bitches. Because color is considered immaterial in judging whippets, they come in a wide variety of colors and marking patterns, everything from solid black to solid white, with red, fawn, brindle, blue, or cream. All manner of spots and blazes and patches are seen, sometimes all in the same litter.

Temperament
Whippets are generally quiet and gentle dogs, and may be content to spend much of the day resting.[1] Although especially attached to their owners, they are friendly to visitors. They are not prone to snapping, so they are good with young children. Because of their friendly nature whippets are known to have been used in aged care facilities.[citation needed] They may bark when strangers arrive but are not suited to being guard dogs. They do, however, tend to attack cats that stray into their territory, unless they have been brought up living with a cat.



Unlike some other breeds, male whippets are as easy to housebreak as females. Male whippets are also as unaggressive as female whippets. Males are sometimes considered to be slightly more loyal and enjoy repetitive play. Females can be a little more complex and strong-willed. Males tend to be one to two inches taller and three to six pounds heavier than females.

Whippet sleeping in the 'cockroach' position characteristic of sighthounds
Whippets are not well-adapted for living in a kennel, or as outside dogs. Their coats do not provide insulation to withstand prolonged periods in cold temperatures. Their natural attachment to people makes them happiest when kept indoors. They are most at home in the company of their owners--in their lap or lying next to them on the lounge. Whippets are quiet and thus well suited to apartment life, although like all dogs they need regular, healthy exercise. The chance to run free in open spaces should be made available to the whippet; however care should be taken with whippets on the street as it is difficult to instill any sort of traffic sense into them.

Whippets have been called a "poor man's racehorse." As their heritage would suggest, whippets are outstanding running dogs and are top competitors in lure coursing, straight racing, and oval track racing. Typically in these events, a temporary track and lure system is set up. The lure is usually a white plastic trash bag, sometimes in conjunction with a "squawker" to simulate a sort of prey sound or with a small piece of animal pelt. With the advent of new methods in motivational obedience training being used, whippets are becoming successful obedience dogs. Many enjoy flyball and agility.

A May 7, 2007 article in Science Daily [2] reported on a genetic mutation that may account for the abnormally high athletic ability of Whippets.

The elegance and ease of grooming of the whippet have made it a somewhat popular in the sport of conformation showing. It has, however, never quite gained the popularity of such dog show stalwarts as the poodle.

Whippets are known for their loving nature and big "smile".

Health
Given proper nutrition, exercise, and veterinary care, most whippets live for 12 to 15 years.[3] They are generally healthy, and are not prone to the frequent ear infections, skin allergies, or digestive problems that can afflict other breeds. Genetic eye defects, though quite rare, have been noted in the breed. Because of this the American Whippet Club recommends that all breeders test for this defect in their breeding stock. Hip dysplasia is unknown in whippets. Undescended testicles are common in the breed. Whippets, like most sighthounds, are sensitive to barbiturate anesthetics. The Whippet is one of the fastest dogs.

The heart of a whippet is large and slow beating, often being arrhythmic or even intermittent when the animal is at rest. This sometimes causes concern to the owner, or to the vet not experienced with the breed. Whippets will, however, demonstrate a regular heartbeat during exercise. In a health survey conducted by The Kennel Club (UK) cardiac problems were shown to be the second leading cause of mortality in Whippets.[4] It is not clear, however, whether this is at all related to the breed's somewhat unusual heart function.

A 2007 study[5] identified a myostatin mutation particular to whippets that is significantly associated with their athletic performance. Whippets with a single copy of this mutation are generally very fast; those with two copies have disproportionately large musculature and are known as "bully whippets".[6][7]

History

Oval Track race meet in Northern California
Whippets were bred to hunt by sight, coursing game in open areas at high speeds. One can find numerous representations of small greyhound-like hounds in art dating back to Roman times but the first written English use of the word "whippet" with regard to a type of dog was in 1610. There is a picture by Jean Baptiste Oudry (1686–1755) of "Misse", one of two English whippets presented to Louis XV, in the Washington National Gallery and another, with her companion, "Turlu", by the same artist in the Musée National de Fontainebleau. However, some French sources, notably the Ministry of Culture, use the word "levrette" to describe Misse and Turlu. Levrette translates as "female greyhound". In the nineteenth century, whippet racing was a national sport in England, more popular than football. It is only beginning with this period that the existence of the whippet as a distinct breed can be stated with certainty. The age of the modern whippet dawned in 1890 when the English Kennel Club granted the breed official recognition, thus making the whippet eligible for competition in dog shows, and commencing the recording of their pedigrees. In the United States, the whippet was recognized in 1888 by the American Kennel Club. Early specimens were taken from the race track by dog fanciers of the time and exported all over the world. The whippet's versatility as a hunting, racing, exhibition or companion dog soon made it one of the most popular of the sighthound breeds.


Domestic rabbit













A domestic rabbit is any of the several varieties of European rabbit that has been domesticated
Male rabbits are called bucks; females are called does. An older term for an adult rabbit is coney (derived from the Dutch word konijn), while rabbit referred only to the young animals.[2] More recently, the term kit or kitten has been used to refer to a young rabbit. A young hare is called a leveret; this term is sometimes informally applied to a young rabbit as well.


History

Rabbits kept in battery cages for scientific experimentation
Phoenician sailors visiting the coast of Spain circa 1100 B.C.E., mistaking the European rabbit for a species from their homeland, gave it the name i-shepan-ham. A corruption of this name, used by the Romans, became the Latin name for Spain, Hispania.[citation needed] In Rome rabbits were raised in large walled colonies. These captive rabbits were raised as food and permitted to interbreed at will.[citation needed]

Selective breeding of rabbits began in the Middle Ages, when they were first treated as domesticated farm animals. By the 1500s, several new breeds of different colors and sizes were being recorded.

In the 1800s, as animal fancy in general began to emerge, rabbit fanciers began to attend rabbit shows in Western Europe and the United States. Breeds were created and modified for the purpose of exhibition, a departure from the breeds that had been created for food, fur, or wool. The rabbit's emergence as a household pet began during the Victorian era. The domestic rabbit continues to be popular as a show animal and pet. Rabbit shows occur in many places and are sanctioned in Canada and the United States by the American Rabbit Breeders' Association (ARBA).

Rabbits have and continue to be used in laboratory work such as production of antibodies for life-saving vaccines and research of human male reproductive system toxicology. The Environmental Health Perspective, published by the National Institute of Health, states, "The rabbit [is] an extremely valuable model for studying the effects of chemicals or other stimuli on the male reproductive system." According to the Humane Society of the United States, rabbits are also used extensively in the study of bronchial asthma, stroke prevention treatments, cystic fibrosis, diabetes, and cancer. Animal rights activists have opposed animal experimentation for non-medical purposes, such as the testing of cosmetic and cleaning products, which has resulted in decreased the use of rabbits in these areas.[citation needed]

Breeds

Holland Lop with black patches on white ("broken")
Main article: List of rabbit breeds
There are many different breeds of domestic rabbit, including the English Angora, Lionhead, Dwarf Hotot, Chinchilla, Dutch, Flemish Giant, Himalayan, Netherland Dwarf,Holland Lop, Silver, Silver fox, English spot, Havana, Florida White, New Zealand, Rex, Polish, Jersey Wooly, Satin, and Mini Lop. As with breeds of dogs, rabbit breeds were generally created by humans at different times for different purposes and vary in physical characteristics, care requirements, and temperaments just as the various dog breeds do. There are over 47 rabbit breeds recognized by the American Rabbit Breeders Association in the United States. There are many more breeds of rabbits worldwide.

Diet
The diet of a domestic rabbit varies depending on the purpose it is kept for. The most important component of a pet rabbit's diet is hay. Hay is the base of pelleted feeds. In addition to pelleted feeds, Timothy hay, orchard grass hay, or an oat hay blend are a necessary and very important part of a rabbit's diet. These kinds of hays provides more fiber than other types of hays. Fresh water in clean bowls or water bottles must be available to rabbits at all times. When a rabbit's sensitive digestive system is stable after weaning, vegetables and some fruits may be introduced safely if they are introduced slowly and cautiously. Avoid seeds, nuts and corn. Overfeeding of treats such as apples, bananas, carrots and other sugary foods can lead to obesity or GI stasis, a condition that can be fatal if not treated.

Rabbits as pets

Rabbits have been kept as pets in Western nations since the 1800s. Like all pets, rabbits need a considerable amount of care and attention. Rabbits kept indoors with proper care can expect to live between 9 to 12 years.[3] Rabbits are especially popular as pets during Easter, due to their association with the holiday. However, animal shelters that accept rabbits often complain that during the weeks and months following Easter, there is a rise of unwanted and neglected rabbits that were bought on impulse or as Easter "gifts", especially for children.[4]
House rabbit organizations warn that a rabbit does not make a good pet for small children because they do not know how to stay quiet, calm, and gentle around the rabbit. As prey animals, rabbits are alert, timid creatures that startle easily. They have fragile bones, especially in their backs, that require support on the belly and bottom when picked up. A scared bunny may bite or scratch a child holding it in a precarious grip and be dropped, seriously injuring the animal, or kick hard enough to fracture or break their own backs. Children 10 years old and older tend to have the maturity and skill required to care for a rabbit.[citation needed]

Socialization with other rabbits
Rabbits are social animals. The process of introducing two rabbits in a common space is called bonding. Until two rabbits are bonded, they tend to fight with each other. Fighting is often the result of territoriality or sexual mounting, which is engaged in by rabbits of both genders upon other rabbits of either gender; this behavior stresses the rabbit being mounted and can make it aggressive toward its cage mate. Bonding rabbits requires additional care to protect against unwanted pregnancy and the spread of disease or parasites.

Acquiring a rabbit
There are many rescue groups, humane societies, and local city animal shelters and individuals that have rabbits available for adoption, typically for a small fee. Additionally, reputable breeders and some pet stores sell rabbits. Pet stores are often considered the least preferable place to acquire a new rabbit as the rabbit's history is unknown, and many come from pet farms with poor conditions.[5] Some stores, however, do document the history of their stock, which can be used to verify their environmental conditions.

Training and play
Rabbits can be taught to follow voice commands much like a dog or cat, but they can also be trained to recognize different patterns of the voice. Rabbits can be taught their names, although they recognize the pattern of the noises more than the words.[citation needed] Rabbits can be very playful and enjoy games and toys. Toys keep a rabbit from becoming bored or frustrated. Rabbits have a tendency to chew on items in their space, particularly wires, although some can be encouraged not to chew dangerous or valuable items by offering alternatives such as chew toys.[6] Some pet rabbit owners prevent access to electrical wires by blocking them off or using cord covers, such as corrugated tubing available at hardware stores.

Socialization with other animals
Rabbits often get along well with declawed house cats, although care should be used when introducing these natural adversaries.

Some books recommend keeping rabbits and guinea pigs together to meet their social needs. While there is varied success with this technique, some have recommended that rabbits should not be kept in the same cage with guinea pigs.[7] A rabbit can easily harass or injure a guinea pig, leading to severe distress, injury, or even death for the guinea pig. Occasionally an unneutered male may attempt to mate with a guinea pig and injure it.[citation needed] Rabbits and guinea pigs also have differing nutritional requirements and therefore require separate foods. Despite formerly proposed social compatibility and their mutual status as small herbivores, rabbits and guinea pigs do in fact have very different social signals and activities. For instance, guinea pigs generally do not practice social grooming.[citation needed] Additionally, rabbits often harbour Bordatella bacteria, which is lethal to guinea pigs should they become infected.[citation needed]

Housing
Prior to the trend in keeping rabbits as house pets, most pet rabbits were kept outdoors in hutches.[citation needed] Today, a wide selection of indoor and outside housing choices are available designed just for rabbits.

Rabbits kept as pets indoors are often referred to as house rabbits; they live in homes with humans much as cats and dogs do. This helps human and pet form a close relationship. As with other pets, rabbits housed indoors are protected from outside predators, temperature extremes, and outdoor parasites. Accommodations can range from a large cage or pen to the free run of the home, depending upon the needs of the family and the personality and physical abilities of the rabbit(s).

When the proper protection from outdoor predators (such as dogs) is provided, rabbits can be safely housed outdoors in well situated runs, hutches, and rabbitries. A rabbitry is housing specifically made for raising rabbits mainly used by rabbit exhibitors (or fanciers) and other reputable breeders. A rabbitry may be a barn, shed, studio, or other safe enclosure. Many rabbitries have electricity, running water, rodent-safe storage for hay and food, a grooming area, and even dishwashers. Many reputable breeders have various temperature control mechanisms for their rabbitries such as electric air conditioning, heating, swamp coolers, or misting systems for cooling the air. Rabbitries range from the very simple to the very elaborate and may house anywhere from 3 to 300 rabbits depending on size and the goals and purposes of the breeder.

Meat rabbits

Meat-type rabbits being raised as a supplementary food source during the Great Depression
Breeds such as the New Zealand and Californian are most frequently utilized for meat in commercial rabbitries. These breeds have efficient metabolisms and grow quickly; they are ready for slaughter by approximately 14 - 16 weeks of age.

Rabbit fryers are rabbits that are between 70 to 90 days of age and weighing between 3 to 5 lb (1 to 2 kg) live weight. Rabbit roasters are rabbits from 90 days to 6 months of age weighing between 5 to 8 lb (2 to 3.5 kg) live weight. Rabbit stewers are rabbits from 6 months on weighing over 8 lb.

Any type of rabbit exhibiting "commercial" body type can be slaughtered for meat. Dark fryers (any other color but albino whites) are usually docked in price by packers because of the slightly darker tinge of the fryer (purely pink carcasses are preferred by consumers) and because the hide is harder to remove manually than the white albino fryers.
Well-known chef Mark Bittman says that domesticated rabbit tastes like chicken because both are blank palettes upon which any desired flavors can be layered [8].

Wool rabbits
Rabbits such as the Angora, American Fuzzy Lop, and Jersey Wooly produce wool. However, since the American Fuzzy Lop and Jersey Wooly are both dwarf breeds, only the much larger Angora breeds such as the English Angora, Satin Angora, Giant Angora, and French Angoras are used for commercial wool production. Their long fur is sheared, combed, or plucked (gently pulling loose hairs from the body during molting) and then spun into yarn used to make a variety of products. Angora sweaters can be purchased in many clothing stores and is generally mixed with other types of wool. Rabbit wool, called Angora, is 5 times warmer than sheep's wool.[citation needed]

Laboratory rabbits
Rabbits have and continue to be used in laboratory work such as production of antibodies for vaccines and research of human male reproductive system toxicology. The Environmental Health Perspective, published by the National Institute of Health, states, "The rabbit [is] an extremely valuable model for studying the effects of chemicals or other stimuli on the male reproductive system."[citation needed] According to the Humane Society of the United States, rabbits are also used extensively in the study of bronchial asthma, stroke prevention treatments, cystic fibrosis, diabetes, and cancer.

Animal rights activists generally oppose animal experimentation for all purposes. However, strong protesting by activists against non-medical testing, such as the testing of cosmetic and cleaning products, has resulted in the decreased use of rabbits in these areas.[citation needed] However, the highly controversial Draize test is still used commonly on rabbits. Albino rabbits are used in eye irritancy tests such as the Draize because rabbits have less tear flow than other animals and the lack of eye pigment make the effects easier to visualize.

Outdoor housing
Outdoor housing for rabbits is usually designed to provide protection from predators. It must provide protection from the elements in winter and keep them cool in summer heat. Whether housed indoors or out, all rabbits should be handled properly and often and provided enrichment items such as shelves, ramps, balls, or other toys. To protect from predators rabbit hutches should be situated in a fenced yard, shed, barn, or other enclosed structure,
Rabbits produce quantities of waste that can be measured in cubic yards per year. This waste is excellent for gardening and composting, and can be collected for these uses whether the rabbit is housed indoors or outdoors. An outdoor cage should be as large as possible, at least high enough for the rabbit to stand on its back legs without its head touching the ceiling. It should be large enough to enable the rabbit to take 4 or 5 hops along its length and/or width. Rabbits should be checked at least once each day for signs of parasites, such as ticks and botflies. The shelter may be heated in winter (although many rabbits can be kept outside with extra bedding even into temperatures below freezing) and should be shaded or otherwise appropriately cooled in summer. Rabbit keepers ensure that clean water is always available to the rabbit in hot weather to keep temperatures below 85 degrees. Large rabbits (such as the New Zealand breed) do fine in temperatures as low as -10 degrees Celsius/15 degrees Fahrenheit in a hutch with plenty of straw, if their needs for food and water are well met. Water bottles that become frozen in cold weather must be changed two or three times daily. Below -10 degrees Celsius/15 degrees Fahrenheit it is necessary to shelter all animals in a barn or basement or garage. Covering cages three quarters of the way with a blanket, several cages grouped together, can generate a great deal of heat. One rule of thumb is at least eight pounds of animal per cage. Even newborn rabbits do well in cold if they have sufficient nest and many siblings to snuggle with. They should stay with the mother for longer periods of time in the winter for warmth. Domesticated rabbits are most comfortable in temperatures between 10 to 21 degrees C (50 to 70 degrees F), and cannot endure temperatures above 32 degrees C (90 degrees F) without assistance such as fans, frozen water bottles, and deep shade.

Rabbits require clean environments and all housing should be cleaned regularly to ensure that no build-up of feces or urine occurs. Rabbits are often raised in cages made entirely of wire which are self cleaning, allowing the urine and droppings to fall through the floor. These rabbits are often provided with sitting boards or mats made of plywood, large ceramic tiles, or smooth slotted mats made of flexible but hard pvc for rabbits to rest upon. Wire bottom floors allow rabbit droppings to be quickly and easily collected without disturbing the rabbit. Rabbit droppings are often left in beds with red worms to create compost, added to compost bins for enrichment of the compost, or applied directly to a garden as a "cool" fertilizer that will not burn plants. Wire cages are easier to clean and sanitize than wooden hutches which may not provide adequate protection from the elements and predators as housing rabbits in a rabbit barn or shed called a rabbitry.

Rabbit owners who house their pets in solid bottom cages must be diligent in cleaning the bedding in the cage as urine scald which can irritate the rabbit's hocks (back feet).


Mule deer

The mule deer (Odocoileus hemionus) is a deer whose habitat is in the western half of North America. It gets its name from its large mule-like ears. Adult male mule deer are called bucks, adult females are called does, and young of both sexes are called fawns. Its closest relative is the black-tailed deer (considered by some a subspecies of mule deer). Unlike its cousin, the white-tailed deer, mule deer are generally more associated with the land west of the Missouri River. The most noticeable differences between whitetails and muleys are the color of their tails and configuration of their antlers. The mule deer's tail is black tipped. Mule deer antlers "fork" as they grow rather than branching from a single main beam (as with white-tails). Each year a buck's antlers start to grow in spring and are shed after mating season from mid-January to mid-April. Mule deer bucks have somewhat more prominent ears than females. Instead of running, mule deer move with a bounding leap (stotting) with all four feet coming down together.

The mule deer is the largest of the Odocoileus genus, standing, on the average, 40 to 42 inches at the shoulders and stretching 80 inches or so nose to tail. An adult buck will weigh from 150 to 300 pounds on the hoof, with does averaging 100 to 175 pounds. The occasional trophy-sized mule deer buck may weigh in around 400 pounds.

Seasonal behaviors
In addition to movements related to available shelter and food, the breeding cycle is important in understanding deer behavior and personality. The "rut" or mating season usually begins in the fall as does go into estrus for a period of a few days and males become more aggressive, competing for mates. Does may mate with more than one buck and go back into estrus within a month if they do not mate. The gestation period is approximately 190–200 days, with fawns born in the spring, staying with their mothers during the summer and being weaned in the fall after approximately 60–75 days. A buck's antlers fall off during the winter, to grow again in preparation for the next season's rut. For more information see main article on deer.

Foraging
In summer, it chiefly forages on not only herbaceous plants, but also various berries (including blackberry, huckleberry, salal, and thimbleberry). Mule deer are known to forage in summer on California Buckeye leaves, even though their is some evidence of that plant's toxicity.[2] In winter, it forages on conifers (especially twigs of Douglas fir, cedar, Taxus yews, aspen, willow, dogwood, serviceberry, juniper, and sage). Year-round, it eats acorns and apples.

Mule Deer grazing in Zion National Park.

A Mule Deer doe grazing near the Devon Lakes.
Mule deer prefer "edge" habitats where the trees meet the grass, and their populations tend to move up or down with those of their preferred foods. Mule deer rarely travel far from water or forage, and tend to bed down within easy walking distance of both. Young mule deer tend to forage together in family groups while bucks tend to travel alone or with other bucks. Most actively foraging around dawn and dusk, they tend to bed down in protected areas mid-day, but will also forage at night in more open agricultural areas or when pressured by hunters. Repeated beds will often be scratched level, about the size of a washtub. Temporary beds will seem little more than flattened grassy grounds.

Jackal

A jackal (from Turkish çakal, via Persian shaghal ultimately from Sanskrit sṛgālaḥ [1][2]) is a member of any of three (sometimes four) small to medium-sized species of the family Canidae, found in Africa, Asia and southeastern Europe.[3] Jackals fill a similar ecological niche to the coyote in North America, that of predators of small to medium-sized animals, scavengers, and omnivores. Their long legs and curved canine teeth are adapted for hunting small mammals, birds and reptiles. Big feet and fused leg bones give them a long-distance runner's physique, capable of maintaining speeds of 16km/h (10mph) (just over 6 min/mile) for extended periods of time. They are nocturnal, most active at dawn and dusk.

In jackal society the social unit is that of a monogamous pair which defends its territory from other pairs. These territories are defended by vigorously chasing intruding rivals and marking landmarks around the territory with urine and feces. The territory may be large enough to hold some young adults who stay with their parents until they establish their own territory. Jackals may occasionally assemble in small packs, for example to scavenge a carcass, but normally hunt alone or as a pair.

All species of jackal are capable predators (all three hunt rodents and small mammals regularly, with the golden and black-backed species known to hunt poisonous snakes, large ground birds such as bustards, and mammals as large as young antelope). However, their popular image as scavengers has resulted in a negative public image.

The expression "jackalling" is sometimes used to describe the work done by a subordinate in order to save the time of a superior. (For example, a junior lawyer may peruse large quantities of material on behalf of a barrister.) This came from the tradition that the jackal will sometimes lead a lion to its prey. In other languages, the same word is sometimes used to describe the behavior of persons who try to scavenge scraps from the misfortunes of others; for example, by looting a village from which its inhabitants have fled because of a disaster.
In Nonviolent Communication, "jackal language" refers to communication that labels, judges, and criticizes.

Reindeer

The reindeer (Rangifer tarandus), also known as the caribou when wild in North America, is an Arctic and Subarctic-dwelling deer, widespread and numerous across the northern Holarctic.

The reindeer is widespread and numerous in the northern Holarctic. Originally it was found in Scandinavia, Eastern Europe, Russia, Mongolia, and northern China north of the 50th latitude. In North America it was found in Alaska, Canada, and the northern U.S. States from Washington to Maine. In the 19th century, it was apparently still present in southern Idaho. It also occurred naturally on Sakhalin, Greenland, and probably even in historical time in Scotland and Ireland. During the late Pleistocene, reindeer were found as far south as Nevada and Tennessee in North America and Spain in Europe.[1][2] Today, wild reindeer have disappeared from many areas within this large historical range, especially from the southern parts where it vanished almost everywhere. Large populations of wild reindeer are still found in Siberia, Greenland, Alaska, and Canada. Domesticated reindeer are mostly found in northern Scandinavia, Russia, and Iceland (where they were introduced by humans in the 18th century). The last wild reindeer in Europe are found in portions of southern Norway.[3]The southern boundary of the species' natural range is approximately at 62° north latitude.

Southern-most reindeer: a South Georgian reindeer with velvet-covered horns.
A few reindeer from Norway were introduced to the South Atlantic island of South Georgia in the beginning of the 20th century. Today there are two distinct herds still thriving there, permanently separated by glaciers. Their total numbers are no more than a few thousand. The flag and the coat of arms of the territory contain an image of a reindeer.
Around 4,000 reindeer have been introduced into the French subantarctic archipelago of Kerguelen Islands.

Biology and behavior

Reindeer antlers grow again each year under a layer of fur called velvet. This reindeer is currently losing the velvet layer on one of its antlers.

Anatomy
The weight of a female varies between 60 and 170 kg (130 and 370 lb). In some subspecies of reindeer, the male is slightly larger; in others, the male can weigh up to 300 kg (660 lb). Both sexes grow antlers,[4] which (in the Scandinavian variety) for old males fall off in December, for young males in the early spring, and for females, summer. The antlers typically have two separate groups of points (see image), a lower and upper. Domesticated reindeer are shorter-legged and heavier than their wild counterparts.

Reindeer have specialized noses featuring nasal turbinate bones that dramatically increase the surface area within the nostrils. Incoming cold air is warmed by the animal's body heat before entering the lungs, and water is condensed from the expired air and captured before the deer's breath is exhaled, used to moisten dry incoming air and possibly absorbed into the blood through the mucous membranes.

Reindeer hooves adapt to the season: in the summer, when the tundra is soft and wet, the footpads become spongy and provide extra traction. In the winter, the pads shrink and tighten, exposing the rim of the hoof which cuts into the ice and crusted snow to keep it from slipping. This also enables them to dig down (an activity known as "cratering")[5][6] through the snow to their favorite food, a lichen known as reindeer moss. The knees of many species of reindeer are adapted to produce a clicking sound as they walk.
The reindeer coat has two layers of fur, a dense woolly undercoat and longer-haired overcoat consisting of hollow, air-filled hairs.

Diet
Reindeer are ruminants, having a four-chambered stomach. They mainly eat lichens in winter, especially reindeer moss. However, they also eat the leaves of willows and birches, as well as sedges and grasses. There is some evidence to suggest that on occasion they will also feed on lemmings,[7] arctic char, and bird eggs.[8] Reindeer herded by the Chukchis have been known to enthusiastically devour mushrooms in late summer.[9]

Herd of Barren-ground Caribou on the Thelon River

Reproduction
Mating occurs from late September or October to early November. Males battle for access to females. Two males will lock each other’s antlers together and try to push each other away. The most dominant males can collect as many as 15-20 females to mate with. A male will stop eating during this time and lose much of its body reserves. Calves may be born the following May or June. After 45 days, the calves are able to graze and forage but continue suckling until the following fall and become independent from their mothers.

Migration
The reindeer travels the furthest of any terrestrial mammal. The caribou of North America can run at speeds up to 80 km/h (50 mph) and can travel as much as 5,000 km (3,100 mi) a year. Migrations can number in the thousands. The most extensive migrations occur in spring and fall. During fall migrations, the groups become smaller and the reindeer begin to mate. During the winter, reindeer travel to forested areas to forage under the snow. By spring, groups leave their winter grounds to go to the calving grounds. A reindeer can swim easily and quickly; migrating herds will not hesitate to swim across a large lake or broad river.

Reindeer and humans

Hunting
See also: Reindeer hunting in Greenland
Reindeer hunting by humans has a very long history and caribou/wild reindeer "may well be the species of single greatest importance in the entire anthropological literature on hunting."[10]
Humans started hunting reindeer in the Mesolithic and Neolithic periods and humans are today the main predator in many areas. Norway and Greenland have unbroken traditions of hunting wild reindeer from the ice age until the present day. In the non-forested mountains of central Norway, such as Jotunheimen, it is still possible to find remains of stone built trapping pits, guiding fences, and bow rests, built especially for hunting reindeer. These can, with some certainty, be dated to the Migration Period although it is not unlikely that they have been in use since the Stone Age.

Norway is now preparing to apply for nomination as a World Heritage Site for areas with traces and traditions of reindeer hunting in Central Sørlandet (Southern Norway).
Wild caribou are still hunted in North America and Greenland. In the traditional lifestyle of the Inuit people, Northern First Nations people, Alaska Natives, and the Kalaallit of Greenland, the caribou is an important source of food, clothing, shelter, and tools.

Reindeer husbandry

A reindeer sled, Arkhangelsk, Russia. Late nineteenth century photochrom.

Milking reindeer in the 19th century
Reindeer have been herded for centuries by several Arctic and Subarctic people including the Sami and the Nenets. They are raised for their meat, hides, antlers and, to a lesser extent, for milk and transportation. Reindeer are not considered fully domesticated, as they generally roam free on pasture grounds. In traditional nomadic herding, reindeer herders migrate with their herds between coast and inland areas according to an annual migration route, and herds are keenly tended. However, reindeer have never been bred in captivity, though they were tamed for milking as well as for use as draught animals or beasts of burden.

The use of caribou as semi-domesticated livestock in Alaska was introduced in the late 1800s by Sheldon Jackson as a means of providing a livelihood for Native peoples there. A regular mail run in Wales, Alaska used a sleigh drawn by caribou. In Alaska, caribou herders use satellite telemetry to track their herds, using online maps and databases to chart the herd's progress.

Economy
The reindeer has (or has had) an important economic role for all circumpolar peoples, including the Saami, Nenets, Khants, Evenks, Yukaghirs, Chukchi, and Koryaks in Eurasia. It is believed that domestication started between the Bronze and Iron Age. Siberian deer owners also use the reindeer to ride on (Siberian reindeer are larger than their Scandinavian relatives). For breeders, a single owner may own hundreds or even thousands of animals. The numbers of Russian herders have been drastically reduced since the fall of the Soviet Union. The fur and meat is sold, which is an important source of income. Reindeer were introduced into Alaska near the end of the 19th century; they interbreed with native caribou subspecies there. Reindeer herders on the Seward Peninsula have experienced significant losses to their herds from animals (such as wolves) following the wild caribou during their migrations.

Reindeer meat is popular in the Scandinavian countries. Reindeer meatballs are sold canned. Sautéed reindeer is the best-known dish in Lapland. In Alaska and Finland, reindeer sausage is sold locally to supermarkets and grocery stores.
Reindeer antler is powdered and sold as an aphrodisiac, nutritional or medicinal supplement to Asian markets.
Caribou have been a major source of subsistence for Canadian Inuit.

In History
The first written description of reindeer is in Julius Caesar's Commentarii de Bello Gallico (chapter 6.26) from the 1st century BC. Here, it is described:
There is an ox shaped like a stag. In the middle of its forehead a single horn grows between its ears, taller and straighter than the animal horns with which we are familiar. At the top this horn spreads out like the palm of a hand or the branches of a tree. The females are of the same form as the males, and their horns are the same shape and size.

Local names
The name Caribou comes, through French, from Mi'kmaq qalipu, meaning "snow-shoveler", referring to its habit of pawing through the snow for food.[11] In Inuktitut, the caribou is known by the name tuttuk (Labrador dialect).

Subspecies

The characteristic reindeer in Svalbard
Reindeer have been divided since 1961 into two major groups, the tundra reindeer with six subspecies and the woodland reindeer with three subspecies. Among the tundra subspecies are three small-bodied, high-artic island forms. These island subspecies are probably not closely related, since the svalbard reindeer seems to have evolved from large european reindeer, whereas peary caribou and the extinct arctic reindeer are closely related and probably having evolved in high-arctic North America[12].

Tundra reindeer
Arctic reindeer (R. tarandus eogroenlandicus), an extinct subspecies found until 1900 in eastern Greenland.
Peary Caribou (R. tarandus pearyi), found in the northern islands of the Nunavut and the Northwest Territories of Canada.
Svalbard Reindeer (R. tarandus platyrhynchus), found on the Svalbard islands of Norway, is the smallest subspecies of reindeer.

Mountain/Wild Reindeer (R. tarandus tarandus), found in the Arctic tundra of Eurasia, including the Fennoscandia peninsula of Northern Europe.
Porcupine caribou or Grant's Caribou (R. tarandus granti) which are found in Alaska, the Yukon, and the Northwest Territories of Canada.

Barren-ground Caribou (R. tarandus groenlandicus), found in Nunavut and the Northwest Territories of Canada and in western Greenland.

Woodland reindeer
Finnish Forest Reindeer (R. tarandus fennicus), found in the wild in only two areas of the Fennoscandia peninsula of Northern Europe, in Finnish/Russian Karelia, and a small population in central south Finland. The Karelia population reaches far into Russia, however, so far that it remains an open question whether reindeer further to the east are R. t. fennicus as well.

Woodland Caribou (R. tarandus caribou), or forest caribou, once found in the North American taiga (boreal forest) from Alaska to Newfoundland and Labrador and as far south as New England and Washington. Woodland Caribou have disappeared from most of their original southern range and are considered "threatened" where they remain, with the notable exception of the Migratory Woodland Caribou of northern Quebec and Labrador, Canada. The name of the Cariboo district of central British Columbia relates to their once-large numbers there, but they have almost vanished from that area in the last century. A herd is protected in the Caribou Mountains in Alberta.

Queen Charlotte Islands caribou (R. tarandus dawsoni) from Haida Gwaii was believed to represent a distinct subspecies. It became extinct at the beginning of the 20th century. However, recent DNA analysis from mitochondrial DNA of the remains from those reindeer suggest, that the animals from Haida Gwaii were not genetically distinct from the Canadian mainland reindeer subspecies

Giraffe

Giraffes are the world's tallest mammals, thanks to their towering legs and long necks. A giraffe's legs alone are taller than many humans—about 6 feet (1.8 meters). These long legs allow giraffes to run as fast as 35 miles (56 kilometers) an hour over short distances and cruise comfortably at 10 miles (16 kilometers) an hour over longer distances.Typically, these fascinating animals roam the open grasslands in small groups of about half a dozen.Bulls sometimes battle one another by butting their long necks and heads. Such contests aren't usually dangerous and end when one animal submits and walks away.Giraffes use their height to good advantage and browse on leaves and buds in treetops that few other animals can reach (acacias are a favorite). Even the giraffe's tongue is long! The 21-inch (53-centimeter) tongue helps them pluck tasty morsels from branches. Giraffes eat most of the time and, like cows, regurgitate food and chew it as cud. A giraffe eats hundreds of pounds of leaves each week and must travel miles to find enough food.The giraffe's height also helps it to keep a sharp lookout for predators across the wide expanse of the African savanna.The giraffe's stature can be a disadvantage as well—it is difficult and dangerous for a giraffe to drink at a water hole. To do so they must spread their legs and bend down in an awkward position that makes them vulnerable to predators like Africa's big cats. Giraffes only need to drink once every several days; they get most of their water from the luscious plants they eat.Female giraffes give birth standing up. Their young endure a rather rude welcome into the world by falling more than 5 feet (1.5 meters) to the ground at birth. These infants can stand in half an hour and run with their mothers an incredible ten hours after birth.Giraffes have beautiful spotted coats. While no two individuals have exactly the same pattern, giraffes from the same area appear similar.

White-Tailed Deer

White-tailed deer, the smallest members of the North American deer family, are found from southern Canada to South America. In the heat of summer they typically inhabit fields and meadows using clumps of broad-leaved and coniferous forests for shade. During the winter they generally keep to forests, preferring coniferous stands that provide shelter from the harsh elements.Adult white-tails have reddish-brown coats in summer which fade to a duller grayish-brown in winter. Male deer, called bucks, are easily recognizable in the summer and fall by their prominent set of antlers, which are grown annually and fall off in the winter. Only the bucks grow antlers, which bear a number of tines, or sharp points. During the mating season, also called the rut, bucks fight over territory by using their antlers in sparring matches.Female deer, called does, give birth to one to three young at a time, usually in May or June and after a gestation period of seven months. Young deer, called fawns, wear a reddish-brown coat with white spots that helps them blend in with the forest.White-tailed deer are herbivores, leisurely grazing on most available plant foods. Their stomachs allow them to digest a varied diet, including leaves, twigs, fruits and nuts, grass, corn, alfalfa, and even lichens and other fungi. Occasionally venturing out in the daylight hours, white-tailed deer are primarily nocturnal or crepuscular, browsing mainly at dawn and dusk.In the wild, white-tails, particularly the young, are preyed upon by bobcats, mountain lions, and coyotes. They use speed and agility to outrun predators, sprinting up to 30 miles (48 kilometers) per hour and leaping as high as 10 feet (3 meters) and as far as 30 feet (9 meters) in a single bound.Although previously depleted by unrestricted hunting in the United States, strict game-management measures have helped restore the white-tailed deer population.

Warthog

Warthogs are members of the same family as domestic pigs, but present a much different appearance. These sturdy hogs are not among the world's most aesthetically pleasing animals—their large, flat heads are covered with "warts," which are actually protective bumps. Warthogs also sport four sharp tusks. They are mostly bald, but they do have some sparse hair and a thicker mane on their backs.Though warthogs appear ferocious, they are basically grazers. They eat grasses and plants, and also use their snouts to dig or "root" for roots or bulbs. When startled or threatened, warthogs can be surprisingly fast, running at speeds of up to 30 miles (48 kilometers) an hour.Warthogs are adaptable and are able to go long periods without water, as much as several months in the dry season.When water is available, warthogs will seek it and often submerge to cool down. They will also wallow in mud for the same purpose—and to gain relief from insects. Birds also aid these hogs in their battle with insects; oxpeckers and other species sometimes ride along on their warthog hosts, feeding on the tiny creatures invading their hides.These African hogs often utilize empty dens created by aardvarks. Rather than fight, they often choose flight, and search for such a den to use as a hidey-hole. They typically back in, using their tusks to effectively guard the entrance.Warthogs also use these dens to have their young. Females have litters of four or fewer young, which they suckle for about four months.

Grizzly Bear

The grizzly bear is a North American subspecies of the brown bear.These awe-inspiring giants tend to be solitary animals—with the exception of females and their cubs—but at times they do congregate. Dramatic gatherings of grizzly bears can be seen at prime Alaskan fishing spots when the salmon run upstream for summer spawning. In this season, dozens of bears may gather to feast on the fish, craving fats that will sustain them through the long winter ahead.Brown bears dig dens for winter hibernation, often holing up in a suitable-looking hillside. Females give birth during this winter rest and their offspring are often twins.Grizzly bears are powerful, top-of-the-food-chain predators, yet much of their diet consists of nuts, berries, fruit, leaves, and roots. Bears also eat other animals, from rodents to moose.Grizzlies are typically brown, though their fur can appear to be white-tipped, or grizzled, lending them their traditional name.Despite their impressive size, grizzlies are quite fast and have been clocked at 30 miles (48 kilometers) an hour. They can be dangerous to humans, particularly if surprised or if humans come between a mother and her cubs.Grizzlies once lived in much of western North America and even roamed the Great Plains. European settlement gradually eliminated the bears from much of this range, and today only about 1,000 grizzlies remain in the continental U.S., where they are protected by law. Many grizzlies still roam the wilds of Canada and Alaska, where hunters pursue them as big game trophies.

Domestic Cat

Domestic cats, no matter their breed, are all members of one species. Felis catus has had a very long relationship with humans. Ancient Egyptians may have first domesticated cats as early as 4,000 years ago. Plentiful rodents probably drew wild felines to human communities. The cats' skill in killing them may have first earned the affectionate attention of humans. Early Egyptians worshipped a cat goddess and even mummified their beloved pets for their journey to the next world—accompanied by mummified mice! Cultures around the world later adopted cats as their own companions.Like their wild relatives, domestic cats are natural hunters able to stalk prey and pounce with sharp claws and teeth. They are particularly effective at night, when their light-reflecting eyes allow them to see better than much of their prey. Cats also enjoy acute hearing. All cats are nimble and agile, and their long tails aid their outstanding balance.Cats communicate by marking trees, fence posts, or furniture with their claws or their waste. These scent posts are meant to inform others of a cat's home range. House cats employ a vocal repertoire that extends from a purr to a screech.Domestic cats remain largely carnivorous, and have evolved a simple gut appropriate for raw meat. They also retain the rough tongue that can help them clean every last morsel from an animal bone (and groom themselves). Their diets vary with the whims of humans, however, and can be supplemented by the cat's own hunting successes.

Human

Human beings, humans or man (Origin: 1590–1600; < L homō man; OL hemō the earthly one (see humus),[3] also Homo sapiens — Latin: "wise human" or "knowing human"),[4] are bipedal primates in the family Hominidae.[5][6] DNA evidence indicates that modern humans originated in Africa about 200,000 years ago. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, problem solving and emotion. This mental capability, combined with an erect body carriage that frees the forelimbs (arms) for manipulating objects, has allowed humans to make far greater use of tools than any other species. Humans are distributed worldwide, large populations inhabiting every continent on Earth except Antarctica. The human population on Earth is greater than 6.7 billion, as of July, 2008.[7] There is only one extant subspecies, Homo sapiens sapiens. As of 2008, humans are listed as a species of least concern for extinction by the International Union for Conservation of Nature.[2]

Like most higher primates, humans are social by nature. Humans are particularly adept at utilizing systems of communication for self-expression, exchanging of ideas, and organization. Humans create complex social structures composed of many cooperating and competing groups, from families to nations. Social interactions between humans have established an extremely wide variety of traditions, rituals, ethics, values, social norms, and laws, which together form the basis of human society. Humans have a marked appreciation for beauty and aesthetics, which, combined with the desire for self-expression, has led to cultural innovations such as art, writing, literature and music.

Humans are notable for their desire to understand and influence the world around them, seeking to explain and manipulate natural phenomena through philosophy, art, science, mythology and religion. This natural curiosity has led to the development of advanced tools and skills; humans are the only species known to build fires, cook their food, clothe themselves; they also manipulate and develop numerous other technologies. Humans pass down their skills and knowledge to the next generations through education.

History
Origin

For more details on this topic, see Anthropology, Human evolution, Recent African Origin, and Archaic Homo sapiens.

A reconstruction of Australopithecus afarensis, a human ancestor that had developed bipedalism, but which lacked the large brain of modern humans.

The scientific study of human evolution encompasses the development of the genus Homo, but usually involves studying other hominids and hominines as well, such as Australopithecus. "Modern humans" are defined as the Homo sapiens species, of which the only extant subspecies is known as Homo sapiens sapiens. Homo sapiens idaltu (roughly translated as "elder wise human"), the other known subspecies, is now extinct.[8] Homo neanderthalensis, which became extinct 30,000 years ago, has sometimes been classified as a subspecies, "Homo sapiens neanderthalensis", but genetic studies now suggest a divergence of the Neanderthal species from Homo sapiens at least 400,000 years ago, and its description is not included here. Similarly, the few specimens of Homo rhodesiensis have also occasionally been classified as a subspecies, but this is not widely accepted. Anatomically modern humans first appear in the fossil record in Africa about 130,000 years ago, although studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago.[9][10][11]

The closest living relatives of Homo sapiens are two chimpanzee species: the Common Chimpanzee and the Bonobo. Full genome sequencing has resulted in the conclusion that "after 6.5 [million] years of separate evolution, the differences between chimpanzee and human are just ten times greater than those between two unrelated people and ten times less than those between rats and mice". Suggested concurrence between human and chimpanzee DNA sequences range between 95% and 99%.[12][13][14][15] It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from that of gorillas about eight million years ago. However, a hominid skull discovered in Chad in 2001, classified as Sahelanthropus tchadensis, is approximately seven million years old, which may indicate an earlier divergence.[16]

The Recent African Origin (RAO), or "out-of-Africa", hypothesis proposes that modern humans evolved in Africa before later migrating outwards to replace hominids in other parts of the world. Evidence from archaeogenetics accumulating since the 1990s has lent strong support to RAO, and has marginalized the competing multiregional hypothesis, which proposed that modern humans evolved, at least in part, from independent hominid populations.[17] Geneticists Lynn Jorde and Henry Harpending of the University of Utah propose that the variation in human DNA is minute compared to that of other species. They also propose that during the Late Pleistocene, the human population was reduced to a small number of breeding pairs – no more than 10,000, and possibly as few as 1,000 – resulting in a very small residual gene pool. Various reasons for this hypothetical bottleneck have been postulated, one being the Toba catastrophe theory.

Human evolution is characterized by a number of important morphological, developmental, physiological and behavioural changes, which have taken place since the split between the last common ancestor of humans and chimpanzees. The first major morphological change was the evolution of a bipedal locomotor adaptation from an arboreal or semi-arboreal one,[18] with all its attendant adaptations, such as a valgus knee, low intermembral index (long legs relative to the arms), and reduced upper-body strength.

Later, ancestral humans developed a much larger brain – typically 1,400 cm³ in modern humans, over twice the size of that of a chimpanzee or gorilla. The pattern of human postnatal brain growth differs from that of other apes (heterochrony), and allows for extended periods of social learning and language acquisition in juvenile humans. Physical anthropologists argue that the differences between the structure of human brains and those of other apes are even more significant than their differences in size.

Other significant morphological changes included: the evolution of a power and precision grip;[19] a reduced masticatory system; a reduction of the canine tooth; and the descent of the larynx and hyoid bone, making speech possible. An important physiological change in humans was the evolution of hidden oestrus, or concealed ovulation, which may have coincided with the evolution of important behavioural changes, such as pair bonding. Another significant behavioural change was the development of material culture, with human-made objects becoming increasingly common and diversified over time. The relationship between all these changes is the subject of ongoing debate.[20][21]

The forces of natural selection have continued to operate on human populations, with evidence that certain regions of the genome display directional selection in the past 15,000 years.[22]

Transition to civilization
For more details on this topic, see History of the world.
The rise of agriculture, and domestication of animals, led to stable human settlements.
The most widely accepted view among current anthropologists is that Homo sapiens originated in the African savanna around 200,000 BP (Before Present), descending from Homo erectus, had inhabited Eurasia and Oceania by 40,000 BP, and inhabited the Americas at least 14,500 years ago.[23] They displaced Homo neanderthalensis and other species descended from Homo erectus (which had inhabited Eurasia as early as 2 million years ago) through more successful reproduction and competition for resources.

Until c. 10,000 years ago, most humans lived as hunter-gatherers. They generally lived in small nomadic groups known as band societies. The advent of agriculture prompted the Neolithic Revolution, when access to food surplus led to the formation of permanent human settlements, the domestication of animals and the use of metal tools. Agriculture encouraged trade and cooperation, and led to complex society. Because of the significance of this date for human society, it is the epoch of the Holocene calendar or Human Era.

About 6,000 years ago, the first proto-states developed in Mesopotamia, and in the Sahara/Nile and the Indus Valleys. Military forces were formed for protection, and government bureaucracies for administration. States cooperated and competed for resources, in some cases waging wars. Around 2,000–3,000 years ago, some states, such as Persia, India, China, Rome, and Greece, developed through conquest into the first expansive empires. Influential religions, such as Judaism, originating in the Middle East, and Hinduism, a religious tradition that originated in South Asia, also rose to prominence at this time.

The late Middle Ages saw the rise of revolutionary ideas and technologies. In China, an advanced and urbanized society promoted innovations and sciences, such as printing and seed drilling. The Islamic Golden Age saw major scientific advancements in Muslim empires. In Europe, the rediscovery of classical learning and inventions such as the printing press led to the Renaissance in the 14th century. Over the next 500 years, exploration and colonialism brought much of the Americas, Asia, and Africa under European control, leading to later struggles for independence. The Scientific Revolution in the 17th century and the Industrial Revolution in the 18th – 19th centuries promoted major innovations in transport, such as the railway and automobile; energy development, such as coal and electricity; and government, such as representative democracy and Communism.

With the advent of the Information Age at the end of the 20th century, modern humans live in a world that has become increasingly globalized and interconnected. As of 2008, over 1.4 billion humans are connected to each other via the Internet,[24] and 3.3 billion by mobile phone subscriptions.[25]

Although interconnection between humans has encouraged the growth of science, art, discussion, and technology, it has also led to culture clashes, the development and use of weapons of mass destruction, and increased environmental destruction and pollution, affecting not only themselves but also most other life forms on the planet.

Habitat and population
For more details on this topic, see Demography and World population.

Humans often live in family-based social structures and create artificial shelter
Early human settlements were dependent on proximity to water and, depending on the lifestyle, other natural resources, such as arable land for growing crops and grazing livestock, or seasonally by hunting populations of prey. However, humans have a great capacity for altering their habitats by various methods, such as through irrigation, urban planning, construction, transport, manufacturing goods, deforestation and desertification. With the advent of large-scale trade and transport infrastructure, proximity to these resources has become unnecessary, and in many places, these factors are no longer a driving force behind the growth and decline of a population. Nonetheless, the manner in which a habitat is altered is often a major determinant in population change.

Technology has allowed humans to colonize all of the continents and adapt to all climates. Within the last few decades, humans have explored Antarctica, the ocean depths, and space, although long-term habitation of these environments is not yet possible. With a population of over six billion, humans are among the most numerous of the large mammals. Most humans (61%) live in Asia. The remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%).

Human habitation within closed ecological systems in hostile environments, such as Antarctica and outer space, is expensive, typically limited in duration, and restricted to scientific, military, or industrial expeditions. Life in space has been very sporadic, with no more than thirteen humans in space at any given time. Between 1969 and 1972, two humans at a time spent brief intervals on the Moon. As of early 2008, no other celestial body has been visited by human beings, although there has been a continuous human presence in space since the launch of the initial crew to inhabit the International Space Station on October 31, 2000. Other celestial bodies have, however, been visited by human-made objects.

Since 1800, the human population has increased from one billion to over six billion.[26] In 2004, some 2.5 billion out of 6.3 billion people (39.7%) lived in urban areas, and this percentage is expected to continue to rise throughout the 21st century. In February 2008, the U.N. estimated that half the world's population will live in urban areas by the end of the year.[27] Problems for humans living in cities include various forms of pollution and crime,[28] especially in inner city and suburban slums. Benefits of urban living include increased literacy, access to the global canon of human knowledge and decreased susceptibility to rural famines.

Humans have had a dramatic effect on the environment. It has been hypothesized that human predation has contributed to the extinction of numerous species. As humans are rarely preyed upon, they have been described as superpredators.[29] Currently, through land development and pollution, humans are thought to be the main contributor to global climate change.[30] This is believed to be a major contributor to the ongoing Holocene extinction event, a mass extinction which, if it continues at its current rate, is predicted to wipe out half of all species over the next century

Elephant
Elephants (family: Elephantidae) are large land mammals of the order Proboscidea. There are three living species: the African Bush Elephant, the African Forest Elephant and the Asian Elephant (also known as the Indian Elephant). Other species have become extinct since the last ice age, the Mammoths being the best-known of these. They were once classified along with other thick skinned animals in a now invalid order, Pachydermata.

Elephants are the largest land animals.[1] The elephant's gestation period is 22 months, the longest of any land animal. At birth it is common for an elephant calf to weigh 120 kilograms (260 lb). They typically live for 50 to 70 years, but the oldest recorded elephant lived for 82 years.[2] The largest elephant ever recorded was shot in Angola in 1956. This male weighed about 12,000 kilograms (26,000 lb),[3] with a shoulder height of 4.2 metres (14 ft), a metre (yard) taller than the average male African elephant.[4] The smallest elephants, about the size of a calf or a large pig, were a prehistoric species that lived on the island of Crete during the Pleistocene epoch.[5]

The elephant has appeared in cultures across the world. They are a symbol of wisdom in Asian cultures and are famed for their memory and intelligence, where they are thought to be on par with cetaceans[6] and hominids.[7] Aristotle once said the elephant was "the beast which passeth all others in wit and mind"[8]. The word "elephant" has its origins in the Greek ἐλέφας, meaning "ivory" or "elephant".[9]

Healthy adult elephants have no natural predators[10], although lions may take calves or weak individuals.[11][12] They are, however, increasingly threatened by human intrusion and poaching. Once numbering in the millions, the African elephant population has dwindled to between 470,000 and 690,000 individuals.[13] The elephant is now a protected species worldwide, with restrictions in place on capture, domestic use, and trade in products such as ivory.

Taxonomy and evolution
See also Elephant classification
The African Elephant genus contains two (or, arguably, three) living species; whereas, the Asian Elephant species is the only surviving member of the Asian Elephant genus, but can be divided into four subspecies.

Evolution of elephants from the ancient Eocene (bottom) to the modern day (top).
Although the fossil evidence is uncertain, scientists discovered genetic evidence that the elephant family shares distant ancestry with the sirenians (sea cows) and the hyraxes through gene comparisons. In the distant past, members of the hyrax family grew to large sizes, and it seems likely that the common ancestor of all three modern families was some kind of amphibious hyracoid. One theory suggests that these animals spent most of their time under water, using their trunks like snorkels for breathing.[14][15] Modern elephants have retained this ability and are known to swim in that manner for up to 6 hours and 50 km (30 miles).
In the past, there was a much wider variety of elephant genera, including the mammoths, stegodons and deinotheria. There was also a much wider variety of species.[16][17]

African Elephant
Main articles: African Elephant, African Bush Elephant, and African Forest Elephant

Elephant crossing a river, Kenya.
Female African elephant with calf, in Kenya.
African bush (savanna) elephant in Mikumi National Park, Tanzania.
The Elephants of the genus Loxodonta, known collectively as African elephants, are currently found in 37 countries in Africa.

African elephants are distinguished from Asian elephants in several ways, the most noticeable being their ears which are much larger. The African elephant is typically larger than the Asian elephant and has a concave back. Both African males and females have external tusks and are usually less hairy than their Asian cousins.

African elephants have traditionally been classified as a single species comprising two distinct subspecies, namely the savanna elephant (Loxodonta africana africana) and the forest elephant (Loxodonta africana cyclotis), but recent DNA analysis suggests that these may actually constitute distinct species.[18] This split is not universally accepted by experts[19] and a third species of African elephant has also been proposed.[20]

This reclassification has important implications for conservation, because it means that where previously it was assumed that a single and endangered species comprised two small populations, if in reality these are two separate species, then as a consequence, both could be more gravely endangered than a more numerous and wide-ranging single species might have been. There is also a potential danger in that, if the forest elephant is not explicitly listed as an endangered species, poachers and smugglers might be able to evade the law forbidding trade in endangered animals and their body parts.

The Forest elephant and the Savanna elephant can also hybridise – that is, breed together – successfully, though their preferences for different terrains reduce such opportunities. As the African elephant has only recently been recognized to comprise two separate species, groups of captive elephants have not been comprehensively classified and some could well be hybrids.

Under the new two species classification, Loxodonta africana refers specifically to the Savanna Elephant, the largest of all elephants. In fact, it is the largest land animal in the world, with the males standing 3.2 metres (10 ft) to 4 metres (13 ft) at the shoulder and weighing 3,500 kilograms (7,700 lb) to a reported 12,000 kilograms (26,000 lb).[21]. The female is smaller, standing about 3 metres (9.8 ft) at the shoulder[22]. Most often, Savanna Elephants are found in open grasslands, marshes, and lakeshores. They range over much of the savanna zone south of the Sahara.

The other putative species, the Forest Elephant (Loxodonta cyclotis), is usually smaller and rounder, and its tusks thinner and straighter compared with the Savanna Elephant. The Forest Elephant can weigh up to 4,500 kilograms (9,900 lb) and stand about 3 metres (10 ft) tall. Much less is known about these animals than their savanna cousins, because environmental and political obstacles make them difficult to study. Normally, they inhabit the dense African rain forests of central and western Africa, although occasionally they roam the edges of forests, thus overlapping the Savanna elephant territories and hybridizing. In 1979, Iain Douglas-Hamilton estimated the continental population of African elephants at around 1.3 million animals.[23] This estimate is controversial and is believed to be a gross overestimate,[24] but it is very widely cited and has become a de facto baseline that continues to be incorrectly used to quantify downward population trends in the species. Through the 1980s, Loxodonta received worldwide attention due to the dwindling numbers of major populations in East Africa, largely as a result of poaching. Today, according to IUCN’s African Elephant Status Report 2007[25] there are approximately between 470,000 and 690,000 African elephants in the wild. Although this estimate only covers about half of the total elephant range, experts do not believe the true figure to be much higher, as it is unlikely that large populations remain to be discovered.[26] By far the largest populations are now found in Southern and Eastern Africa, which together account for the majority of the continental population. According to a recent analysis by IUCN experts, most major populations in Eastern and Southern Africa are stable or have been steadily increasing since the mid-1990s, at an average rate of 4.5% per year.[27][28]

Elephant populations in West Africa, on the other hand, are generally small and fragmented, and only account for a small proportion of the continental total.[29] Much uncertainty remains as to the size of the elephant population in Central Africa, where the prevalence of forest makes population surveys difficult, but poaching for ivory and bushmeat is believed to be intense through much of the region.[30] South Africa elephant population more than doubled, rising from 8,000 to over 20,000, in the thirteen years after a 1995 ban on killing the animals.[31] The ban was lifted in February 2008, sparking controversy among environmental groups.[32]

Asian Elephant
Main article: Asian Elephant
The Asian elephant, Elephas maximus, is smaller than the African. It has smaller ears, and typically, only the males have large external tusks.

An Asian elephant named Sri Hari during Sree Poornathrayesa temple festival, Thrippunithura.
A decorated Indian elephant in Jaipur, India.
"O Elephante" - Hand-coloured engraving drawn by H.Gobin and engraved by Ramus[33]

Elephant in Sri Lanka
The world population of Asian elephants – also called Indian Elephants – is estimated to be around 60,000, about a tenth of the number of African elephants. More precisely, it is estimated that there are between 38,000 and 53,000 wild elephants and between 14,500 and 15,300 domesticated elephants in Asia with perhaps another 1,000 scattered around zoos in the rest of the world.[34] The Asian elephants' decline has possibly been more gradual than the African and caused primarily by poaching and habitat destruction by human encroachment.

Several subspecies of Elephas maximus have been identified, using morphometric data and molecular markers. Elephas maximus maximus (Sri Lankan Elephant) is found only on the island of Sri Lanka. It is the largest of the Asians. There are an estimated 3,000–4,500 members of this subspecies left today in the wild, although no accurate census has been carried out recently. Large males can weigh upward to 5,400 kg (12,000 lb) and stand over 3.4 m (11 ft) tall. Sri Lankan males have very large cranial bulges, and both sexes have more areas of depigmentation than other Asians. Typically, their ears, face, trunk, and belly have large concentrations of pink-speckled skin. There is an orphanage for elephants in Pinnawala, Sri Lanka, which plays a large role in protecting the Sri Lankan Elephant from extinction.

Elephas maximus indicus (Indian Elephant) makes up the bulk of the Asian elephant population. Numbering approximately 36,000, these elephants are lighter grey in colour, with depigmentation only on the ears and trunk. Large males will ordinarily weigh only about 5,000 kg (11,000 lb), but are as tall as the Sri Lankan. The mainland Asian can be found in 11 Asian countries, from India to Indonesia. They prefer forested areas and transitional zones, between forests and grasslands, where greater food variety is available.

The smallest of all the elephants is the Sumatran Elephant, Elephas maximus sumatranus. Population estimates for this group range from 2,100 to 3,000 individuals. It is very light grey in colour and has less depigmentation than the other Asians, with pink spots only on the ears. Mature Sumatrans will usually only measure 1.7–2.6 m (5.6–8.5 ft) at the shoulder and weigh less than 3,000 kg (6,600 lb). It is considerably smaller than its other Asian (and African) cousins and exists only on the island of Sumatra, usually in forested regions and partially wooded habitats.

In 2003, a further subspecies was identified on Borneo. Named the Borneo pygmy elephant, it is smaller and tamer than any other Asian elephants. It also has relatively larger ears, longer tail and straighter tusks.

Physical characteristics

Trunk
The proboscis, or trunk, is a fusion of the nose and upper lip, elongated and specialized to become the elephant's most important and versatile appendage. African elephants are equipped with two fingerlike projections at the tip of their trunk, while Asians have only one. According to biologists, the elephant's trunk may have over forty thousand individual muscles in it,[35] making it sensitive enough to pick up a single blade of grass, yet strong enough to rip the branches off a tree. Some sources indicate that the correct number of muscles in an elephant's trunk is closer to one hundred thousand.[36]

Most herbivores (plant eaters, like the elephant) possess teeth adapted for cutting and tearing off plant materials. However, except for the very young or infirm, elephants always use their trunks to tear up their food and then place it in their mouth. They will graze on grass or reach up into trees to grasp leaves, fruit, or entire branches. If the desired food item is too high up, the elephant will wrap its trunk around the tree or branch and shake its food loose or sometimes simply knock the tree down altogether.

The trunk is also used for drinking. Elephants suck water up into the trunk (up to fifteen quarts or fourteen litres at a time) and then blow it into their mouth. Elephants also inhale water to spray on their body during bathing. On top of this watery coating, the animal will then spray dirt and mud, which act as a protective sunscreen. When swimming, the trunk makes an excellent snorkel.[14][15]

This appendage also plays a key role in many social interactions. Familiar elephants will greet each other by entwining their trunks, much like a handshake. They also use them while play-wrestling, caressing during courtship and mother / child interactions, and for dominance displays – a raised trunk can be a warning or threat, while a lowered trunk can be a sign of submission. Elephants can defend themselves very well by flailing their trunk at unwanted intruders or by grasping and flinging them.

An elephant can use its trunk for a variety of purposes. This one is wiping its eye.
An elephant also relies on its trunk for its highly developed sense of smell. Raising the trunk up in the air and swivelling it from side to side, like a periscope, it can determine the location of friends, enemies, and food sources.

Tusks
The tusks of an elephant are its second upper incisors. Tusks grow continuously; an adult male's tusks will grow about 18 cm (7 in) a year. Tusks are used to dig for water, salt, and roots; to debark trees, to eat the bark; to dig into baobab trees to get at the pulp inside; and to move trees and branches when clearing a path. In addition, they are used for marking trees to establish territory and occasionally as weapons.

Like humans who are typically right- or left-handed, elephants are usually right- or left-tusked. The dominant tusk, called the master tusk, is generally shorter and more rounded at the tip from wear. Both male and female African elephants have large tusks that can reach over 3 m (10 ft) in length and weigh over 90 kg (200 lb). In the Asian species, only the males have large tusks. Female Asians have tusks which are very small or absent altogether. Asian males can have tusks as long as the much larger Africans, but they are usually much slimmer and lighter; the heaviest recorded is 39 kg (86 lb). The tusk of both species is mostly made of calcium phosphate in the form of apatite. As a piece of living tissue, it is relatively soft (compared with other minerals such as rock), and the tusk, also known as ivory, is strongly favoured by artists for its carvability. The desire for elephant ivory has been one of the major factors in the reduction of the world's elephant population.

Some extinct relatives of elephants had tusks in their lower jaws in addition to their upper jaws, such as Gomphotherium, or only in their lower jaws, such as Deinotherium.

Teeth
Elephants' teeth are very different from those of most other mammals. Over their lives they usually have 28 teeth. These are:
The two upper second incisors: these are the tusks.
The milk precursors of the tusks.
12 premolars, 3 in each side of each jaw.
12 molars, 3 in each side of each jaw.

Replica of an Asian Elephant's molar, showing upper side
This gives elephants a dental formula of:
Unlike most mammals, which grow baby teeth and then replace them with a permanent set of adult teeth, elephants have cycles of tooth rotation throughout their entire life. The tusks have milk precursors, which fall out quickly and the adult tusks are in place by one year of age, but the molars are replaced five times in an average elephant's lifetime.[37] The teeth do not emerge from the jaws vertically like with human teeth. Instead, they have move horizontally, like a conveyor belt. New teeth grow in at the back of the mouth, pushing older teeth toward the front, where they wear down with use and the remains fall out. When an elephant becomes very old, the last set of teeth is worn to stumps, and it must rely on softer foods to chew. Very elderly elephants often spend their last years exclusively in marshy areas where they can feed on soft wet grasses. Eventually, when the last teeth fall out, the elephant will be unable to eat and will die of starvation. Were it not for tooth wearout, their metabolism would allow them to live much longer. Rupert Sheldrake has proposed this as an explanation for the elephant graveyards. However, as more habitat is destroyed, the elephants' living space becomes smaller and smaller; the elderly no longer have the opportunity to roam in search of more appropriate food and will, consequently, die of starvation at an earlier age.

Tusks in the lower jaw are also second incisors. These grew out large in Deinotherium and some mastodons, but in modern elephants they disappear early without erupting.

Skin

Skin of an African elephant
Elephants are colloquially called pachyderms (from their original scientific classification), which means thick-skinned animals. An elephant's skin is extremely tough around most parts of its body and measures about 2.5 centimetres (1.0 in) thick. However, the skin around the mouth and inside of the ear is paper-thin. Normally, the skin of an Asian is covered with more hair than its African counterpart. This is most noticeable in the young. Asian calves are usually covered with a thick coat of brownish red fuzz. As they get older, this hair darkens and becomes more sparse, but it will always remain on their heads and tails.

The species of elephants are typically greyish in colour, but the Africans very often appear brown or reddish from wallowing in mud holes of coloured soil. Wallowing is an important behaviour in elephant society. Not only is it important for socialization, but the mud acts as a sunscreen, protecting their skin from harsh ultraviolet radiation. Although tough, an elephant's skin is very sensitive. Without regular mud baths to protect it from burning, as well as from insect bites and moisture loss, an elephant's skin would suffer serious damage. After bathing, the elephant will usually use its trunk to blow dirt on its body to help dry and bake on its new protective coat. As elephants are limited to smaller and smaller areas, there is less water available, and local herds will often come too close over the right to use these limited resources.
Wallowing also aids the skin in regulating body temperatures. Elephants have difficulty in releasing heat through the skin because, in proportion to their body size, they have very little of it. The ratio of an elephant's mass to the surface area of its skin is many times that of a human. Elephants have even been observed lifting up their legs to expose the soles of their feet, presumably in an effort to expose more skin to the air. Since wild elephants live in very hot climates, they must have other means of getting rid of excess heat.

Legs and feet

Elephant using its feet to crush a watermelon prior to eating it
An elephant's legs are great straight pillars, as they must be to support its bulk. The elephant needs less muscular power to stand because of its straight legs and large pad-like feet. For this reason an elephant can stand for very long periods of time without tiring. In fact, African elephants rarely lie down unless they are sick or wounded. Indian elephants, in contrast, lie down frequently.

The feet of an elephant are nearly round. African elephants have three nails on each hind foot, and four on each front foot. Indian elephants have four nails on each hind foot and five on each front foot. Beneath the bones of the foot is a tough, gelatinous material that acts as a cushion or shock absorber. Under the elephant's weight the foot swells, but it gets smaller when the weight is removed. An elephant can sink deep into mud, but can pull its legs out readily because its feet become smaller when they are lifted.[citation needed]
An elephant is a good swimmer, but it can not trot, jump, nor gallop. It does have two gaits: a walk; and a faster gait that is similar to running.

In walking, the legs act as pendulums, with the hips and shoulders rising and falling while the foot is planted on the ground. With no "aerial phase", the faster gait does not meet all the criteria of running, as elephants always have at least one foot on the ground. However, an elephant moving fast uses its legs much like a running animal, with the hips and shoulders falling and then rising while the feet are on the ground. In this gait, an elephant will have three feet off the ground at one time. As both of the hind feet and both of the front feet are off the ground at the same time, this gait has been likened to the hind legs and the front legs taking turns running.[38]
Although they start this "run" at only 8 km/h,[39] elephants can reach speeds up to 25 km/h, all the while using the same gait. At this speed, most other four-legged creatures are well into a gallop, even accounting for leg length. Spring-like kinetics could explain the difference between the motion of elephants and other animals.[40]

Ears

An Elephant sanctuary at Punnathur kotta, Kerala, south India.
The large flapping ears of an elephant are also very important for temperature regulation. Elephant ears are made of a very thin layer of skin stretched over cartilage and a rich network of blood vessels. On hot days, elephants will flap their ears constantly, creating a slight breeze. This breeze cools the surface blood vessels, and then the cooler blood gets circulated to the rest of the animal's body. The hot blood entering the ears can be cooled as much as ten degrees Fahrenheit before returning to the body. Differences in the ear sizes of African and Asian elephants can be explained, in part, by their geographical distribution. Africans originated and stayed near the equator, where it is warmer. Therefore, they have bigger ears. Asians live farther north, in slightly cooler climates, and thus have smaller ears.

The ears are also used in certain displays of aggression and during the males' mating period. If an elephant wants to intimidate a predator or rival, it will spread its ears out wide to make itself look more massive and imposing. During the breeding season, males give off an odour from the musth gland located behind their eyes. Joyce Poole, a well-known elephant researcher, has theorized that the males will fan their ears in an effort to help propel this "elephant cologne" great distances. [41]

Biology and behavior
Social behavior
Elephant footprints (tire tracks for scale)

Elephants live in a structured social order. The social lives of male and female elephants are very different. The females spend their entire lives in tightly knit family groups made up of mothers, daughters, sisters, and aunts. These groups are led by the eldest female, or matriarch. Adult males, on the other hand, live mostly solitary lives.

The social circle of the female elephant does not end with the small family unit. In addition to encountering the local males that live on the fringes of one or more groups, the female's life also involves interaction with other families, clans, and subpopulations. Most immediate family groups range from five to fifteen adults, as well as a number of immature males and females. When a group gets too big, a few of the elder daughters will break off and form their own small group. They remain very aware of which local herds are relatives and which are not.

The life of the adult male is very different. As he gets older, he begins to spend more time at the edge of the herd, gradually going off on his own for hours or days at a time. Eventually, days become weeks, and somewhere around the age of fourteen, the mature male, or bull, sets out from his natal group for good. While males do live primarily solitary lives, they will occasionally form loose associations with other males. These groups are called bachelor herds. The males spend much more time than the females fighting for dominance with each other. Only the most dominant males will be permitted to breed with cycling females. The less dominant ones must wait their turn. It is usually the older bulls, forty to fifty years old, that do most of the breeding.
The dominance battles between males can look very fierce, but typically they inflict very little injury. Most of the bouts are in the form of aggressive displays and bluffs. Ordinarily, the smaller, younger, and less confident animal will back off before any real damage can be done. However, during the breeding season, the battles can get extremely aggressive, and the occasional elephant is injured. During this season, known as musth, a bull will fight with almost any other male it encounters, and it will spend most of its time hovering around the female herds, trying to find a receptive mate.

Males will sometime also engage in same-sex bonding and mounting. Such encounters are often associated with affectionate interactions, such as kissing, trunk intertwining, and placing trunks in each other's mouths. Unlike heterosexual relations however, which are always of a fleeting nature, those between males result in a "companionship", consisting of an older individual and one or two younger, attendant males.[citation needed]

Rogue elephant is a term for a lone, violently aggressive wild elephant. It is a calque of the Sinhala term hora aliya. Its introduction to English has been attributed by the Oxford English Dictionary to Sir James Emerson Tennent, but this usage may have been pre-dated by William Sirr.

Intelligence
Main article:
Elephant intelligence

Human, dolphin and elephant brains up to scale. (1)-cerebrum (1a)-temporal lobe and (2)-cerebellum
With a mass just over 5 kg (11 lb), elephant brains are larger than those of any other land animal, and although the largest whales have body masses twentyfold those of a typical elephant, whale brains are barely twice the mass of an elephant's. A wide variety of behaviours, including those associated with grief, making music, art, altruism, allomothering, play, use of tools,[42] compassion and self-awareness [43] evidence a highly intelligent species on par with cetaceans[6] and primates[7]. The largest areas in the elephant brain are those responsible for hearing, smell and movement coordination.

Senses
Elephants have well innervated trunks, and an exceptional sense of hearing and smell. The hearing receptors reside not only in ears, but also in trunks that are sensitive to vibrations, and most significantly feet, which have special receptors for low frequency sound and are exceptionally well innervated. Elephants communicate by sound over large distances of several kilometers partly through the ground, which is important for their social lives. Elephants are observed listening by putting trunks on the ground and carefully positioning their feet.
Their eyesight is relatively poor, and the eyes are aiming down the trunk. An elephant has to raise his head conspicuously to look out horizontally[citation needed].

Self-awareness
Mirror self recognition is a test of self awareness and cognition used in animal studies. A mirror was provided and visible marks were made on the elephant. The elephants investigated these marks, that were visible only via the mirror. The tests also included non-visible marks to rule out the possibility of their using other senses to detect these marks. This shows that elephants recognize the fact that the image in the mirror is their own self and such abilities are considered the basis for empathy, altruism and higher social interactions. This ability has been demonstrated in humans, apes, dolphins,[44] and magpies.[45]

A young elephant in Zimbabwe.

Communication
In addition to their bellows, roars and widely recognized trumpet-like calls; elephants communicate over long distances by producing and receiving low-frequency sound (infrasound), a sub-sonic rumbling, which can travel through the ground farther than sound travels through the air. This can be felt by the sensitive skin of an elephant's feet and trunk, which pick up the resonant vibrations much as the flat skin on the head of a drum. To listen attentively, every member of the herd will lift one foreleg from the ground, and face the source of the sound, or often lay its trunk on the ground. The lifting presumably increases the ground contact and sensitivity of the remaining legs. This ability is thought also to aid their navigation by use of external sources of infrasound. Discovery of this new aspect of elephant social communication and perception came with breakthroughs in audio technology, which can pick up frequencies outside the range of the human ear. Pioneering research in elephant infrasound communication was done by Katy Payne, of the Elephant Listening Project,[46] and is detailed in her book Silent Thunder. Though this research is still in its infancy, it is helping to solve many mysteries, such as how elephants can find distant potential mates, and how social groups are able to coordinate their movements over extensive range.

Diet
Elephants are herbivores, spending 16 hours a day collecting plant food. Their diet is at least 50% grasses, supplemented with leaves, bamboo, twigs, bark, roots, and small amounts of fruits, seeds and flowers. Because elephants only digest 40% of what they eat, they have to make up for their digestive system's lack of efficiency in volume. An adult elephant can consume 140–270 kg (300–600 lb) of food a day. 60% of that food leaves the elephant's body undigested[citation needed].

Reproduction and life cycle
Elephant calves

Elephant social life revolves around breeding and raising of the calves. A female will usually be ready to breed around the age of thirteen, when she comes into estrus, a short phase of receptiveness lasting a couple of days, for the first time. Females announce their estrus with smell signals and special calls.

Females prefer bigger, stronger, and, most importantly, older males. Such a reproductive strategy tends to increase their offspring's chances of survival.
After a twenty-two-month pregnancy, the mother will give birth to a calf that will weigh about 113 kg (250 lb) and stand over 76 cm (2.5 ft) tall. Elephants have a very long childhood. They are born with fewer survival instincts than many other animals. Instead, they must rely on their elders to teach them the things they need to know. Today, however, the pressures humans have put on the wild elephant populations, from poaching to habitat destruction, mean that the elderly often die at a younger age, leaving fewer teachers for the young.

A new calf is usually the centre of attention for all herd members. All the adults and most of the other young will gather around the newborn, touching and caressing it with their trunks. The baby is born nearly blind and at first relies, almost completely, on its trunk to discover the world around it.

As everyone in the herd is usually related, all members of the tightly knit female group participate in the care and protection of the young. After the initial excitement, the mother will usually select several full-time baby-sitters, or "allomothers", from her group. According to Cynthia Moss, a well known researcher, these allomothers will help in all aspects of raising the calf[47]. They walk with the young as the herd travels, helping the calves along if they fall or get stuck in the mud. The more allomothers a baby has, the more free time its mother has to feed herself. Providing a calf with nutritious milk means the mother has to eat more nutritious food herself. So, the more allomothers, the better the calf's chances of survival. An elephant is considered an allomother when she is not able to have her own baby. A benefit of being an allomother is that she can gain experience or receive assistance when caring for her own calf.

Effect on the environment
Elephants are a species which many other organisms depend on. One particular example of that are termites mounds: termites eat elephant feces and often begin building their mounds under piles of elephant feces.

Elephants' foraging activities can sometimes greatly affect the areas in which they live. By pulling down trees to eat leaves, breaking branches, and pulling out roots they create clearings in which new young trees and other vegetation can establish itself. During the dry season, elephants use their tusks to dig into dry river beds to reach underground sources of water. These newly dug water holes may then become the only source of water in the area. Elephants make pathways through their environment which are also used by other animals to access areas normally out of reach. This pathways have sometimes been used by several generations of elephants and today are converted by humans to paved roads.

Threat of extinction

Men with African Elephant tusks, Dar es Salaam, c. 1900
An Elephant resting his head on a tree trunk, Samburu National Reserve, Kenya

An elephant in the Ngorongoro crater, Tanzania

African Savanna Elephant Loxodonta africana, born 1969 (left), and Asian Elephant Elephas maximus, born 1970 (right), at an English zoo

Hunting
The threat to the African elephant presented by the ivory trade is unique to the species. Larger, long-lived, slow-breeding animals, like the elephant, are more susceptible to overhunting than other animals. They cannot hide, and it takes many years for an elephant to grow and reproduce. An elephant needs an average of 140 kg (300 lb) of vegetation a day to survive. As large predators are hunted, the local small grazer populations (the elephant's food competitors) find themselves on the rise. The increased number of herbivores ravage the local trees, shrubs, and grasses. Elephants themselves have few natural predators besides man and, occasionally, lions.

Habitat loss
Another threat to elephant's survival in general is the ongoing cultivation of their habitats with increasing risk of conflicts of interest with human cohabitants. These conflicts kill 150 elephants and up to 100 people per year in Sri Lanka.[48] Lacking the massive tusks of its African cousins, the Asian elephant's demise can be attributed mostly to loss of its habitat.

As larger patches of forest disappear, the ecosystem is affected in profound ways. The trees are responsible for anchoring soil and absorbing water runoff. Floods and massive erosion are common results of deforestation. Elephants need massive tracts of land because, much like the slash-and-burn farmers, they are used to crashing through the forest, tearing down trees and shrubs for food and then cycling back later on, when the area has regrown. As forests are reduced to small pockets, elephants become part of the problem, quickly destroying all the vegetation in an area, eliminating all their resources.

National parks
Africa's first official reserve, Kruger National Park, eventually became one of the world's most famous and successful national parks. [49] There are, however, many problems associated with the establishment of these reserves. For example, elephants range through a wide tract of land with little regard for national borders. Once a reserve is established and fence erected, many animals find themselves cut off from their winter feeding grounds or spring breeding areas. Some animals may die as a result, while others, like the elephants, may just trample over the fences, wreaking havoc in nearby fields. When confined to small territories, elephants can inflict an enormous amount of damage to the local landscapes. [50]

Additionally, some reserves, such as Kruger National Park has, in the opinion of wildlife managers, suffered from elephant overcrowding, at the expense of other species of wildlife within the reserve. On 25 February 2008, the South Africa announced that they would reintroduce culling for the first time since 1994 to control elephant numbers.[51] Nevertheless, as scientists learn more about nature and the environment, it becomes very clear that these parks may be the elephant's last hope against the rapidly changing world around them.

Humanity and elephants
Further information: cultural depictions of elephants

Harvest from the wild
The harvest of elephants, both legal and illegal, has had some unexpected consequences on elephant anatomy as well. African ivory hunters, by killing only tusked elephants, have given a much larger chance of mating to elephants with small tusks or no tusks at all. The propagation of the absent-tusk gene has resulted in the birth of large numbers of tuskless elephants, now approaching 30% in some populations (compare with a rate of about 1% in 1930). Tusklessness, once a very rare genetic abnormality, has become a widespread hereditary trait.

It is possible, if unlikely, that continued selection pressure could bring about a complete absence of tusks in African elephants, a development normally requiring thousands of years of evolution. The effect of tuskless elephants on the environment, and on the elephants themselves, could be dramatic. Elephants use their tusks to root around in the ground for necessary minerals, tear apart vegetation, and spar with one another for mating rights. Without tusks, elephant behaviour could change dramatically.[52]

Domestication and use
Elephants have been working animals used in various capacities by humans. Seals found in the Indus Valley suggest that the elephant was first domesticated in ancient India. However, elephants have never been truly domesticated: the male elephant in his periodic condition of musth is dangerous and difficult to control. Therefore elephants used by humans have typically been female, war elephants being an exception, however: as female elephants in battle will run from a male, only males could be used in war. It is generally more economical to capture wild young elephants and tame them than breeding them in captivity (see also elephant "crushing").

The Judean rebel Eleazar Maccabeus kills a Seleucid war elephant and is crushed under it (Miniature from a manuscript Speculum Humanae Salvationis).
Elephants are also commonly exhibited in zoos and wild animal parks.

Warfare
Main article: War elephant
War elephants were used by armies in the Indian sub-continent, the Warring States of China, and later by the Persian Empire. This use was adopted by Hellenistic armies after Alexander the Great experienced their worth against king Porus, notably in the Ptolemaic and Seleucid diadoch empires. The Carthaginian general Hannibal took elephants across the Alps when he was fighting the Romans, but brought too few elephants to be of much military use, although his horse cavalry was quite successful; he probably used a now-extinct third African (sub)species, the North African (Forest) elephant, smaller than its two southern cousins, and presumably easier to domesticate. A large elephant in full charge could cause tremendous damage to infantry, and cavalry horses would be afraid of them (see Battle of Hydaspes).

Industry

Elephant work camp in Thailand. Elephants are used for heavy forest work and in circus presentations
Throughout Myanmar (Burma), Siam, India, and most of South Asia elephants were used in the military for heavy labour, especially for uprooting trees and moving logs, and were also commonly used as executioners to crush the condemned underfoot.
Elephants have also been used as mounts for safari-type hunting, especially Indian shikar (mainly on tigers), and as ceremonial mounts for royal and religious occasions, whilst Asian elephants have been used for transport and entertainment.

Zoo and Circuses

Devi (little princess), a 30-year-old Asian Elephant raised in captivity at the San Diego Zoo exhibiting "rocking behavior", a rhythmic and repetitive swaying which is unreported in free ranging wild elephants. Thought to be symptomatic of stress disorders, and probably made worse by a barren environment,[53] rocking behavior may be a precursor to aggressive behavior in captive elephants.[54][55]

Elephants have traditionally been a major part of circuses around the world, being intelligent enough to be trained in a variety of acts (see for example P.T. Barnum's Jumbo and John L. Sullivan, the famous "Boxing Elephant"). However, conditions for circus elephants are highly unnatural (confinement in small pens or cages, restraints on their feet, lack of companionship of other elephants, etc) and, perhaps as a result, there are instances of them turning on their keepers or handlers (examples include Black Diamond and "Murderous Mary").

There is growing resistance[56] against the capture, confinement, and use of wild elephants. Animal rights advocates allege that elephants in zoos and circuses "suffer a life of chronic physical ailments, social deprivation, emotional starvation, and premature death".[57] Zoos argue that standards for treatment of elephants are extremely high and that minimum requirements for such things as minimum space requirements, enclosure design, nutrition, reproduction, enrichment and veterinary care are set to ensure the wellbeing of elephants in captivity. Circuses continue to have a mixed record. Recently, the city of Los Angeles' closed an elephant act with Circus Vazquez due to numerous instances of abuse and neglect (April 2008) [58], and according to PETA, Ringling Bros. and Barnum & Bailey Circus has lost 25 elephants since 1992. [59]

Hybrids
Although successful hybridisation between African and Asian Elephant species is highly unlikely in the wild, in 1978 at Chester Zoo, an Asian elephant cow gave birth to a hybrid calf sired by an African elephant bull (the old terms are used here as these events pre-date the current classifications). "Motty", the resulting hybrid male calf, had an African elephant's cheeks, their ears (large with pointed lobes) and legs (longer and slimmer), but the toenail numbers, (5 for each front foot, 4 hind) and the single trunk finger of an Asian elephant. His wrinkled trunk was like that of an African elephant. His forehead was sloping with one dome and two smaller domes behind it. The body was African in type, but had an Asian-type centre hump and an African-type rear hump. The calf died of infection 12 days later[60]. It is preserved as a mounted specimen at the British Natural History Museum, London. There are unconfirmed rumours of three other hybrid elephants born in zoos or circuses; all are said to have been deformed and none survived.

Elephant rage
Despite its popularity in zoos, and cuddly portrayal as gentle giants in fiction, elephants are among the world's most potentially dangerous animals. They can crush and kill any other land animal, even the rhinoceros. They can experience unexpected bouts of rage, and can be vindictive.[61] In Africa, groups of young teenage elephants attack human villages in what is thought to be revenge for the destruction of their society by massive cullings done in the 1970s and 80s.[62] In India, male elephants attack villages at night, destroying homes and killing people on a regular basis. In the Indian state of Jharkhand, 300 people were killed by elephants between 2000 and 2004, and in Assam, 239 people have been killed by elephants since 2001.[61] In India elephants kills up to 200 humans every year, and in Sri Lanka around 50 per year.

Musth
Main article:
Musth
Adult male elephants naturally periodically enter the state called musth (Hindi for "madness"), sometimes spelt "must" in English.

Other causes
At least a few elephants have been suspected to be drunk during their attacks. In December 1998, a herd of elephants overran a village in India. Although locals reported that nearby elephants had recently been observed drinking beer which rendered them "unpredictable", officials considered it the least likely explanation for the attack.[63] An attack on another Indian village occurred in October 1999, and again locals believed the reason was drunkenness, but the theory was not widely accepted.[64] Purportedly drunk elephants raided yet another Indian village again on December 2002, killing six people, which led to killing of about 200 elephants by locals.

Black Mamba
Black mambas are fast, nervous, lethally venomous, and when threatened, highly aggressive. They have been blamed for numerous human deaths, and African myths exaggerate their capabilities to legendary proportions. For these reasons, the black mamba is widely considered the world’s deadliest snake.Black mambas live in the savannas and rocky hills of southern and eastern Africa. They are Africa’s longest venomous snake, reaching up to 14 feet (4.5 meters) in length, although 8.2 feet (2.5 meters) is more the average. They are also among the fastest snakes in the world, slithering at speeds of up to 12.5 miles per hour (20 kilometers per hour).They get their name not from their skin color, which tends to be olive to gray, but rather from the blue-black color of the inside of their mouth, which they display when threatened.Black mambas are shy and will almost always seek to escape when confronted. However, when cornered, these snakes will raise their heads, sometimes with a third of their body off the ground, spread their cobra-like neck-flap, open their black mouths and hiss. If an attacker persists, the mamba will strike not once, but repeatedly, injecting large amounts of potent neuro- and cardiotoxin with each strike.Before the advent of black mamba antivenin, a bite from this fearsome serpent was 100 percent fatal, usually within about 20 minutes. Unfortunately, antivenin is still not widely available in the rural parts of the mamba’s range, and mamba-related deaths remain frequent.The black mamba has no special conservation status. However, encroachment on its territory is not only putting pressure on the species but contributes to more potentially dangerous human contact with these snakes.

Cnemidophorus sexlineatus
The Six-lined Racerunner (Cnemidophorus sexlineatus) is a species of lizard found in the United States, from Wyoming across the Great Plains east to Rhode Island, south to Florida and west to southern Texas, and in northern Mexico, in Tamaulipas.

Description
The Six-lined Racerunner is typically dark green, brown or black in color, with six yellow or green-yellow stripes that extend down the body from head to tail. The underside is usually white in color on females, and a pale blue in males. Males also sometimes have a pale green colored throat. They are slender bodied, with a tail nearly twice the body length.

Behavior
Like other species of whiptail lizard, the Six-lined Racerunner is diurnal and insectivorous. They are wary, energetic, and fast moving, darting for cover if approached. Due to its extensive range, it is found in a wide variety of habitats including grasslands, woodlands, open floodplains, or rocky outcroppings. It prefers lower elevations, with dry loamy soils. Breeding takes place in the spring and early summer, with up to six eggs being laid in mid-summer and hatch six to eight weeks later. A second clutch of eggs may be laid several weeks after the first.

Wild Turkey
The turkey was Benjamin Franklin's choice for the United States's national bird. The noble fowl was a favored food of Native Americans. When Europeans arrived, they made it one of only two domestic birds native to the Americas—the Muscovy duck shares the distinction.Yet by the early 20th century, wild turkeys no longer roamed over much of their traditional range. They had been wiped out by hunting and the disappearance of their favored woodland habitat.Wild turkeys typically forage on forest floors, but can also be found in grasslands and swamps. They feed on nuts, seeds, fruits, insects, and salamanders.Wild turkey reintroduction programs began in the 1940s, and the birds were relocated to areas where populations had been decimated but woodlands were recovering. Such efforts worked so well that wild turkeys now live in areas where they may not have occurred when Europeans first reached the Americas. Today, flocks are also found in Hawaii, Europe, and New Zealand.Only male turkeys display the ruffled feathers, fanlike tail, bare head, and bright beard commonly associated with these birds. They also gobble with a distinctive sound that can be heard a mile (a kilometer and a half) away.Females lay 4 to 17 eggs, and feed their chicks after they hatch—but only for a few days. Young turkeys quickly learn to fend for themselves as part of mother/child flocks that can include dozens of animals. Males take no role in the care of young turkeys.Domestic turkeys have white-tipped tails because they are the descendants of a Mexican subspecies that was taken to Europe for domestication in the early 16th century. The feature distinguishes them from most modern wild turkeys, though captive diet, lifestyle, and breeding have caused other physical discrepancies.

Squirrel

Squirrels are familiar to almost everyone. More than 200 squirrel species live all over the world, with the notable exception of Australia.The tiniest squirrel is the aptly named African pygmy squirrel—only five inches (thirteen centimeters) long from nose to tail. Others reach sizes shocking to those who are only familiar with common tree squirrels. The Indian giant squirrel is three feet (almost a meter) long.Like other rodents, squirrels have four front teeth that never stop growing so they don't wear down from the constant gnawing. Tree squirrels are the types most commonly recognized, often seen gracefully scampering and leaping from branch to branch. Other species are ground squirrels that live in burrow or tunnel systems, where some hibernate during the winter season.Ground squirrels eat nuts, leaves, roots, seeds, and other plants. They also catch and eat small animals, such as insects and caterpillars. These small mammals must always be wary of predators because they are tasty morsels with few natural defenses, save flight. Sometimes groups of ground squirrels work together to warn each other of approaching danger with a whistling call.Tree squirrels are commonly seen everywhere from woodlands to city parks. Though they are terrific climbers, these squirrels do come to the ground in search of fare such as nuts, acorns, berries, and flowers. They also eat bark, eggs, or baby birds. Tree sap is a delicacy to some species.Flying squirrels are a third, adaptable type of squirrel. They live something like birds do, in nests or tree holes, and although they do not fly, they can really move across the sky. Flying squirrels glide, extending their arms and legs and coasting through the air from one tree to another. Flaps of skin connecting limbs to body provide a winglike surface. These gliding leaps can exceed 150 feet (46 meters). Flying squirrels eat nuts and fruit, but also catch insects and even baby birds.Whether they dwell high in a tree or in an underground burrow, female squirrels typically give birth to two to eight offspring. Babies are blind and totally dependent on their mothers for two or three months. Mothers may have several litters in a year, so most squirrel populations are robust.

Pig

Pigs, also called hogs or swine, are ungulates which have been domesticated as sources of food, leather, and similar products since ancient times. More recently, they have been involved in biomedical research and treatments, especially for their eyes and hearts, which closely resemble those of humans. Their long association with humans has led to their considerable representation in cultural milieux from paintings to proverbs. There are 2 billion pigs on the planet.[1][2]
Native to Eurasia, they are collectively grouped under the genus Sus within the Suidae family. Despite pigs' reputation for gluttony, and another reputation for dirtiness, a lesser known quality is their intelligence. The nearest living relatives of the swine family are the peccaries

Description and behavior

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A pig has a snout for a nose, small eyes, and a small tail, which may be curly, kinked, or straight. It has a thick body, short legs, and coarse hair. There are four toes on each foot, with the two large middle toes used for walking.
Pigs are omnivores, which means that they consume both plants and animals. Pigs will scavenge and have been known to eat any kind of food, including dead insects, worms, tree bark, rotting carcasses, garbage, and even other pigs. In the wild, they are foraging animals, primarily eating leaves, grasses, roots, fruits and flowers. Occasionally while in captivity, pigs may eat their own young if they become severely stressed. A typical pig has a large head with a long snout which is strengthened by a special bone called the prenasal bone and by a disk of cartilage in the tip.[citation needed] The snout is used to dig into the soil to find food and is a very sensitive sense organ.

Pigs have a full set of 44 teeth. The canine teeth, called tusks, grow continually and are sharpened by the lowers and uppers rubbing against each other.
Pigs that are allowed to forage may be watched by swineherds. Because of their foraging abilities and excellent sense of smell, they are used to find truffles in many European countries. Domesticated pigs are commonly raised as livestock by farmers for meat (called pork), as well as for leather. Their bristly hairs are also used for brushes. Some breeds of pigs, such as the Asian pot-bellied pig, are kept as pets.

Breeding occurs throughout the year in the tropics, but births peak around rainy seasons. A female pig can become pregnant at around 8-18 months of age. She will then go into estrus every 21 days if not bred. Male pigs become sexually active at 8-10 months of age.[3] A litter of piglets typically contains between 6 and 12 piglets. After the young are weaned, two or more families may come together until the next mating season.

Pigs do not have functional sweat glands,[4] so pigs cool themselves using water or mud during hot weather. They also use mud as a form of sunscreen to protect their skin from sunburn. Mud also provides protection against flies and parasites.

Chicken

The chicken (Gallus gallus, sometimes G. gallus domesticus) is a domesticated fowl which is traditionally believed to have descended from the wild Red Junglefowl found in India (species: Gallus Gallus).[1] However, some genetic research has suggested that the bird likely descended from both Red and the Grey Junglefowl (G. sonneratii). Although hybrids of both wild types usually tend toward sterility, recent genetic work has revealed that the genotype for yellow skin present in the domestic fowl is not present in what is otherwise its closest kin, the Red Junglefowl. It is deemed most likely, then, that the yellow skin trait in domestic birds originated in the Grey Junglefowl.[2]

As the species spread domestication occurred throughout multiple sites in Asia—including India where it was used for cock fighting.[3] From India the domestication of chicken spread throughout Near East, Africa and the Greco-Roman world.[3]

The chicken is one of the most common and widespread domestic animals. With a population of more than 24 billion in 2003,[4] there are more chickens in the world than any other bird. Humans keep chickens primarily as a source of food, with both their meat and their eggs consumed.

Terminology
In the U.S.A., Canada and Australia, adult male chickens are known as roosters; in the UK they are known as cocks.[citation needed] Males under a year old are cockerels.[5] Castrated roosters are called capons (though both surgical and chemical castration are now illegal in some parts of the world). Females over a year old are known as hens, and younger females are pullets.[6] In Australia and New Zealand (also sometimes in Britain), there is a useful generic term chook (rhymes with "book") to describe all ages and both genders.[7]. Babies are called chicks, and the meat is called chicken.

"Chicken" was originally the word only for chicks, and the species as a whole was then called domestic fowl, or just fowl. This use of "chicken" survives in the phrase "Hen and Chickens," sometimes used as a UK pub or theatre name, and to name groups of one large and many small rocks or islands in the sea (see for example Hen and Chicken Islands).

General biology and habitat

Hen and chicks searching for food in Kosovo
Chickens are omnivores.[8] In the wild, they often scratch at the soil to search for seeds, insects and even larger animals such as lizards or young mice.[9]

Chickens in nature may live for five to eleven years depending on the breed.[10] In commercial intensive farming, a meat Chicken generally lives only six weeks before slaughter.[11] A free range or organic meat chicken will usually be slaughtered at about 14 weeks. Hens of special laying breeds may produce as many as 300 eggs a year. After 12 months, the hen's egg-laying ability starts to decline, and commercial laying hens are then slaughtered and used in baby foods, pet foods, pies and other processed foods.[12] The world's oldest chicken, according to the Guinness Book of World Records, died of heart failure when she was 16 years.[13]

Roosters can usually be differentiated from hens by their striking plumage, marked by long flowing tails and shiny, pointed feathers on their necks and backs (the hackles and saddle)—these are often colored differently from the hackles and saddles of females.

However, in some breeds, such as the Sebright, the cock has only slightly pointed neck feathers, the same colour as the hen's. The identification must be made by looking at the comb, or eventually from the development of spurs on the male's legs (in a few breeds and in certain hybrids the male and female chicks may be differentiated by colour). Adult chickens have a fleshy crest on their heads called a comb or cockscomb, and hanging flaps of skin either side under their beaks called wattles. These organs help to cool the bird by redirecting blood flow to the skin.[citation needed] Both the adult male and female have wattles and combs, but in most breeds these are more prominent in males.

Wild Red Junglefowl- Male at 23 Mile near Jayanti in Buxa Tiger Reserve in Jalpaiguri district of West Bengal, India.

Domestic chickens are not capable of long distance flight, although lighter birds are generally capable of flying for short distances, such as over fences or into trees (where they would naturally roost). Chickens will sometimes fly to explore their surroundings, but usually do so only to flee perceived danger. Because of the risk of escape, chickens raised in open-air pens often have one of their wings clipped by the breeder—the tips of the longest feathers on one of the wings are cut, resulting in unbalanced flight which the bird cannot sustain for more than a few meters, and it is thus discouraged from flying at all.[citation needed]

Chickens are gregarious birds and live together as a flock. They have a communal approach to the incubation of eggs and raising of young. Individual chickens in a flock will dominate others, establishing a "pecking order," with dominant individuals having priority for access to food and nesting locations. Removing hens or roosters from a flock causes a temporary disruption to this social order until a new pecking order is established. Adding hens—especially younger birds—to an existing flock, can lead to violence and injury.[14]

Hens will try to lay in nests that already contain eggs, and have been known to move eggs from neighbouring nests into their own. Some farmers use fake eggs made from plastic or stone (or golf balls) to encourage hens to lay in a particular location. The result of this behavior is that a flock will use only a few preferred locations, rather than having a different nest for every bird.
Hens can also be extremely stubborn about always laying in the same location. It is not unknown for two (or more) hens to try to share the same nest at the same time. If the nest is small, or one of the hens is particularly determined, this may result in chickens trying to lay on top of each other.

Rooster crowing during daylight hours
Contrary to popular belief, roosters do not crow only at dawn, but may crow at any time of the day or night. Their crowing (a loud and sometimes shrill call) is a territorial signal to other roosters. However, crowing may also result from sudden disturbances within their surroundings. Hens cluck loudly after laying an egg, and also to call their chicks.

In 2006, scientists researching the ancestry of birds "turned on" a chicken recessive gene, talpid2, and found that the embryo jaws initiated formation of teeth, like those found in ancient bird fossils. John Fallon, the overseer of the project, stated that chickens have "...retained the ability to make teeth, under certain conditions..."[15]

Courting
When a rooster finds food he may call the other chickens to eat it first. He does this by clucking in a high pitch as well as picking up and dropping the food. This behavior can also be observed in mother hens, calling their chicks. In some cases the rooster will drag the wing opposite the hen on the ground, while circling her. This is part of chicken courting ritual. When a hen is used to coming to his "call" the rooster may mount the hen and proceed with the fertilization.

Breeding

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Chicken eggs vary in color depending on the hen, typically ranging from bright white to shades of brown and even blue, green, and recently reported purple (found in South Asia) (Araucana varieties).

Under natural conditions most birds lay only until a clutch is complete, and they will then incubate all the eggs. Many domestic hens will also do this – and are then said to go broody. The broody hen will stop laying and instead will focus on the incubation of the eggs (a full clutch is usually about 12 eggs). She will sit or set fast on the nest, protesting or pecking in defense if disturbed or removed, and she will rarely leave the nest to eat, drink, or dust-bathe. While brooding, the hen maintains the nest at a constant temperature and humidity, as well as turning the eggs regularly during the first part of the incubation. To stimulate broodiness, an owner may place many artificial eggs in the nest, or to stop it they may place the hen in an elevated cage with an open wire floor.

At the end of the incubation period (about 21 days), the eggs, if fertile, will hatch. Development of the egg starts only when incubation begins, so they all hatch within a day or two of each other, despite perhaps being laid over a period of two weeks or so. Before hatching the hen can hear the chicks peeping inside the eggs, and will gently cluck to stimulate them to break out of their shells. The chick begins by pipping – pecking a breathing hole with its egg tooth towards the blunt end of the egg, usually on the upper side. It will then rest for some hours, absorbing the remaining egg-yolk and withdrawing the blood supply from the membrane beneath the shell (used earlier for breathing through the shell). It then enlarges the hole, gradually turning round as it goes, and eventually severing the blunt end of the shell completely to make a lid. It crawls out of the remaining shell and its wet down dries out in the warmth of the nest.

A day-old chick
The hen will usually stay on the nest for about two days after the first egg hatches, and during this time the newly-hatched chicks live off the egg yolk they absorb just before hatching. Any eggs not fertilized by a rooster will not hatch, and the hen eventually loses interest in these and leaves the nest. After hatching the hen fiercely guards the chicks, and will brood them when necessary to keep them warm, at first often returning to the nest at night. She leads them to food and water – she will call them to edible items, but rarely feeds them directly. She continues to care for them until they are several weeks old, when she will gradually lose interest and eventually start to lay again.

Modern egg-laying breeds rarely go broody, and those that do often stop part-way through the incubation. However, some "utility" (general purpose) breeds, such as the Cochin, Cornish and Silkie, do regularly go broody, and they make excellent mothers, not only for chicken eggs but also for those of other species -- even those with much smaller or larger eggs and different incubation periods, such as quail, pheasants, turkeys or geese. Chicken eggs can also be hatched under a broody duck, with varied success.

Artificial incubation
Chicken egg incubation can successfully occur artificially as well. Nearly all fertilized Chicken eggs will hatch after 21 days of good conditions - 99.5 °F (37.5 °C) and around 55% relative humidity (increase to 70% in the last three days of incubation to help soften egg shell). Eggs must be turned regularly (usually three to eight times each week) during the first part of the incubation. If the eggs aren't turned, the embryo inside will stick to the shell and may hatch with physical defects. Some incubators turn the eggs automatically. This turning mimics the natural process – an incubating hen will stand up several times a day and shift the eggs around with her beak. However, if the egg is turned during the last week of incubation the chick may have difficulty settling in the correct hatching position.

Many commercial incubators are industrial-sized with shelves holding tens of thousands of eggs at a time, with rotation of the eggs a fully automated process. Home incubators are boxes holding from half a dozen to 75 eggs; they are usually electrically powered, but in the past some were heated with an oil or paraffin lamp.

Chickens as food
Main article: Chicken (food)
The meat of the chicken, also called "chicken," is a type of poultry meat. Because of its relatively low cost, chicken is one of the most used meats in the world. Nearly all parts of the bird can be used for food, and the meat can be cooked in many different ways. Popular chicken dishes include fried chicken, chicken soup, Buffalo wings, tandoori chicken, butter chicken, and chicken rice. Chicken is also a staple of fast food restaurants. Commercially produced chicken usually has a fairly neutral flavor and texture,[citation needed] and is used as a reference point for describing other foods; many are said to "taste like chicken" if they are indistinctive.

Chickens as pets
Chickens can make good companion animals and can be tamed by hand feeding, but roosters can sometimes become aggressive. Some have advised against keeping them around very young children. Some people find chickens' behaviour entertaining and educational.

A rooster.
While some cities in the United States allow chickens as pets, the practice is not approved in all localities. Some communities ban only roosters, allowing the quieter hens. The so called "urban hen movement" harks back to the days when chicken keeping was much more common, and involves the keeping of small groups of hens in areas where they may not be expected, such as closely populated cities and suburban areas. City ordinances, zoning regulations or health boards may determine whether chickens may be kept.[3] A general requirement is that the birds be confined to the owner's property, not allowed to roam freely. There may be strictures on how far from human dwellings a coop may be located, etc.[16]

Chickens are generally low-maintenance. The major challenge is protecting the birds from predators such as dogs, raccoons and foxes. A bird left out at night is likely to be killed by a predator. Chickens are usually kept in a roost at night and a pen in the day (unless they are free-range). The floor is covered with bedding such as straw or wood shavings, which, with the high-nitrogen droppings, can go into a compost pile.

Roosters are not required, as hens still lay eggs, but these eggs are not fertilized by the rooster therefore they will not hatch. Fresh egg yolks are "perky" and float above the white. Yolk color varies. According to Gail Damerow's handbook, "Egg yolks get their color from xanthophyll, a natural yellow-orange pigment in green plants and yellow corn, and the same pigment that colors the skin and shanks of yellow-skinned hens. The exact color of a yolk depends on the source of the xanthophyll." A subsequent table ascribes raw yolks colored "orange to dark yellow" to "green feed, yellow corn."[17]

If hens are allowed to forage or are fed additional greens, their eggs may differ from USDA standards. Barb Gorski, a Pennsylvania farmer of pastured poultry, had some of her chicken eggs analyzed under the USDA-supported Sustainable Agriculture Research and Education (SARE) program. According to the laboratory results, "Eggs of the pastured chickens contained 34% less cholesterol, 10% less fat, 40% more vitamin A, twice as much omega-6 fatty acid, and four times as much omega-3 fatty acid as the USDA standard."[18]

While the bulk of a pet chickens' diet should be a balanced commercial mix, for household chickens "green feed" can be as simple as poison-free, short grass clippings from lawn mowing. Chickens will forage for chickweed and other plants, seeds, and insects.

Chickens can also consume pulverized eggshells or otherwise unused food, such as meal leavings and old (but not rotted) produce. Damerow recommends leftover baked goods, fruit, or vegetable peelings, excess milk in modest amounts; advises against making such scraps the sole diet, or including raw potato peels "which chickens can't easily digest..." or "...anything spoiled or rotten...strong-tasting foods like onions, garlic, or fish."[19]

In Asia, chickens with striking plumage have long been kept for ornamental purposes, including feather-footed varieties such as the Cochin from Vietnam, the Silkie from China, and the extremely long-tailed Phoenix from Japan. Asian ornamental varieties were imported into the United States and Great Britain in the late 1800s. Distinctive American varieties of chickens have been developed from these Asian breeds. Poultry fanciers began keeping these ornamental birds for exhibition, a practice that continues today. Individuals in rural communities commonly keep chickens for both ornamental and practical value. Zoos sometimes use chickens instead of insecticides to control insect populations.[

Giant house spider

The Giant house spider (Tegenaria duellica; formerly known as T. gigantea) is a member of the genus Tegenaria and is a close relative of both the Domestic house spider and the infamous Hobo spider. The bite of this species does not pose a threat to humans or pets.

Appearance
Females can reach 18 mm in length, with males having a slightly smaller body at around 12 mm to 15 mm in length. The female leg span is typically around 45 mm. The leg span of the male is highly variable, with spans between 25 mm to 75 mm being common.

The Giant house spider has the same coloration as the Domestic house spider; it has earthy tones of brown and muddy red or yellow. They also have conspicuously hairy legs and abdomen.

Habitat
The Giant house spider is indigenous to north western Europe. It was however unwittingly introduced to the pacific northwest of North America circa 1900 due to human activity and strongly increased in numbers for the last decade.

The webs built by the Giant house spider are flat and messy with a funnel at one end. The spider lurks in the funnel until a small invertebrate happens to get trapped in the web, at which point the spider runs out and attacks it.

They usually build their webs in corners (on both the floor and ceiling), between boxes in basements, attics, or any other area that is rarely disturbed by large animals, or humans.
Males can often be seen wandering around during the late summer and early autumn looking for a mate.

Toxicity
Like most spiders, the spider possesses quite a potent venom to subdue its prey; but it is not known to bite humans.

Speed
With speeds clocked at 1.73 ft/s (0.53 m/s), the giant house spider held the Guinness Book of World Records for top spider speed until 1987 when it was displaced by sun spiders (solpugids) although the latter are not true spiders as they belong to a different order.[1] This species has been seen in humid areas.

Tegenaria duellica can attain a leg span of up to 4 inches (100 mm). This specimen is approximately 3 inches (76 mm).

A population of Giant house spiders is popularly thought to be a deterrent to the establishment of Tegenaria agrestis[citation needed], known in North America as the hobo spider, and considered by some to be more likely to bite humans. Giant house spiders may compete with hobo spiders for the same resources. Hobo spiders grow no more than a body size of 15 millimetres (0.59 in) long as where the larger female giant house spider can have a body size of 18 millimetres (0.71 in)[2], but has proportionately much longer legs[3].

Taxonomy
This species was referred to as Tegenaria gigantea until 1995, when it was first realized that this name was a synonym of T. duellica (published in 1875), making the latter the oldest available name. Other authors suggested that T. gigantea was a synonym of T.saeva, but molecular evidence indicates that these are distinct taxa, not synonyms[4].

Giant tortoise

Giant tortoises are characteristic reptiles of certain tropical islands. They occur (some species are now extinct) in such places as Madagascar, the Seychelles, Mauritius, Réunion, the Galápagos Islands, Sulawesi, Timor, Flores and Java, often reaching enormous size — they can weigh as much as 300 kg (660 lbs) and can grow to be 1.3 m (4 ft) long. However, giant tortoises also once lived on the mainland of Asia and Australia, as follows from fossil finds in the Shivalik Hills in India. Today, the world's largest population inhabits Aldabra Atoll in Seychelles, where there are approximately 100,000 individuals.

These animals belong to the most ancient group of reptiles, appearing about 250 million years ago. In the Upper Cretaceous, 70 or 80 million years ago some already became gigantic and about 1 million years ago these reptiles reached the Galápagos Islands. Until 100,000 years ago most of the gigantic species began to disappear for unknown causes and only 250 years ago there were at least 20 species and subspecies in islands of the Indian Ocean and 14 or 15 species in the Galapagos Islands. From those, only one of the species of the Indian Ocean survives in the wild, the Aldabra Giant Tortoise (two more are claimed to exist in captive or re-released populations, but some genetic studies have cast doubt on the validity of these as separate species) and 11 in Galápagos.

They are one of the world's longest-living animals, with an average lifespan of 100 years or more. Harriet the Turtle, (Charles Darwin's turtle) as reported by the Australia Zoo was 175 years old.

Three-Toed Sloth

The sloth is the world's slowest mammal, so sedentary that algae grows on its furry coat. The plant gives it a greenish tint that is useful camouflage in the trees of its Central and South American rain forest home.Sloths are identified by the number of long, prominent claws that they have on each front foot. There are both two-toed and three-toed sloths.All sloths are built for life in the treetops. They spend nearly all of their time aloft, hanging from branches with a powerful grip aided by their long claws. (Dead sloths have been known to retain their grip and remain suspended from a branch.) Sloths even sleep in trees, and they sleep a lot—some 15 to 20 hours every day. Even when awake they often remain motionless. At night they eat leaves, shoots, and fruit from the trees and get almost all of their water from juicy plants.Sloths mate and give birth while hanging in the trees. Three-toed sloth babies are often seen clinging to their mothers—they travel by hanging on to them for the first nine months of their lives.On land, sloths' weak hind legs provide no power and their long claws are a hindrance. They must dig into the earth with their front claws and use their strong front legs to pull themselves along, dragging their bellies across the ground. If caught on land, these animals have no chance to evade predators, such as big cats, and must try to defend themselves by clawing and biting.Though they couldn't be clumsier on land, sloths are surprisingly good swimmers. They sometimes fall directly from rain forest trees into rivers and stroke efficiently with their long arms.The three-toed sloth emits a long, high-pitched call that echoes through the forests as "ahh-eeee." Because of this cry these sloths are sometimes called ais (pronounced "eyes").Three-toed sloths also have an advantage that few other mammals possess: They have extra neck vertebrae that allows them to turn their heads some 270 degrees.

Snail
The word snail is a common name that can be used for almost all members of the molluscan class Gastropoda which have coiled shells in the adult stage. (Those snails which do not have a shell or only a very small shell are usually called slugs. Snails which have a broadly conical shell which is not coiled, or appears not to be coiled, are often known as limpets.) When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails.
The class of Gastropoda (the snails and slugs) is second only to the insects in terms of total number of species. Snails are extraordinarily diverse in habitat, form, behavior, and anatomy, and therefore what is true of one snail species may not at all be true of another.
Snails can be found in a wide range of different and alike environments from ditches to deserts to the abyssal depths of the sea. The great majority of snail species are marine. Many others are terrestrial, and numerous kinds can be found in fresh water, and even brackish water. Many snails are herbivorous, though a few land species and many marine species are omnivores or predatory carnivores.
Although the average person might perhaps be more familiar with terrestrial snails, land snails are in the minority. Marine snails have much greater diversity, and a greater biomass. Snails which respire using a lung belong to the group Pulmonata, while those with gills form a paraphyletic group, in other words, snails with gills are divided into a number of taxonomic groups that are not very closely related.
Snails with lungs and with gills have diversified widely enough over geological time that a few species with gills can be found on land, numerous species with a lung can be found in freshwater, and a few species with a lung can be found in the sea.

Although the word snail is often used for all shelled gastropods, the word "snail" can also be used in a much more limited sense, to mean various larger species of air-breathing (pulmonate) land snails. The majority of this article is about air-breathing land snails.

Land snails
Species of land snails live in almost every kind of habitat, from deserts and mountains to marshes, woodland, and gardens. However, certain species are "anthropophilic", which means they are found most often around human habitation.

Whichever reasonably large land snail species is most commonly seen or most commonly eaten in a given area, that species will usually be referred to simply as "snails" by the local people. In many parts of the world, the fairly large edible species Helix aspersa or Cornu aspersum, has been introduced, and has become a pest in farms and gardens, so this is perhaps a good example of a species commonly known as "the snail."

Slugs
Gastropod species which lack a conspicuous shell are commonly called slugs rather than snails, although, other than having a reduced shell or no shell at all, there are really no appreciable differences between a slug and a snail except in habitat and behavior. A shell-less animal is much more maneuverable, and thus even quite large land slugs can take advantage of habitats or retreats with very little space – places that would be totally inaccessible to a similar-sized snail, such as under loose bark on trees or under stone slabs, logs or wooden boards lying on the ground.

Taxonomic families of land slugs and sea slugs occur within numerous larger taxonomic groups of shelled species. In other words, the reduction or loss of the shell has evolved many times independently within several very different lineages of gastropods, thus the various families of slugs are very often not closely related to one another.

Physical characteristics
Underside of a snail climbing a blade of grass, showing the muscular foot and the pneumostome on the animal's right side

Most snails move by gliding along on their muscular foot, which is lubricated with mucus. This motion is powered by succeeding waves of muscular contraction which move down the undersurface of the foot. This muscular action is clearly visible when a snail is crawling on the glass of a window or aquarium. Snails move at a proverbially low speed (1 mm/s is a typical speed for adult Helix lucorum[1]). They produce mucus in order to aid locomotion by reducing friction, and the mucus also helps reduce the snail's risk of mechanical injury from sharp objects. This means that they can 'walk' over sharp objects like razors without being injured.[2] Snails also have a mantle, a specialized layer of tissue which covers all of the internal organs as they are grouped together in the visceral mass, and the mantle also extends outward in flaps, which reach to the edge of the shell and in some cases can cover the shell, and which are partially retractible. The mantle is attached to the shell and creates it by secretion.

When retracted into their shells, many snails with gills (including many marine, some freshwater and some terrestrial species) are able to protect themselves with a door-like anatomical structure called an operculum. (The operculum of some sea snails has a pleasant scent when burned, so it is sometimes used as an ingredient in incense.)

Snails range greatly in size. The largest land snail is the Giant African Snail or Ghana Tiger Snail (Achatina achatina; Family Achatinidae), which can measure up to 30 cm. Pomacea maculata (Family Ampullariidae), or Giant Apple Snail is the largest freshwater snail, with a diameter of up to 15 cm and a mass of over 600 g. The biggest of all snails is Syrinx aruanus, an Australian marine species which can grow up to 77.2 cm (30 inches) in length[3] and 18 kg (40lbs) in weight.[4]

As the snail grows, so does its calcium carbonate shell. A snail's shell forms a logarithmic spiral. Most snail shells are right-handed, meaning that if you hold the shell with the apex (the tip, or the juvenile whorls) pointing towards you, then the spiral proceeds in a clockwise direction from the apex to the opening. When the animal reaches full adult size, many species of snails build a thickened lip around the opening of the shell. At this point the animal stops growing, and begins reproducing.

Sinistral (left handed) species of snail from western India
The shells of snails and other molluscs, and some snail egg casings, are primarily made up of calcium carbonate. Because of this, molluscs need calcium in their diet and environment to produce a strong shell. A lack of calcium, or low pH in their surroundings, can result in thin, cracked, or perforated shells. Usually a snail can repair damage to its shell over time if its living conditions improve, but severe damage can be fatal.

Most snails bear one or two pairs of tentacles on their heads. In most land snails the eyes are carried on the tips of the first (upper) set of tentacles (called ommatophores or more informally 'eye stalks') which are usually roughly 75% of the width of the eyes. The second (lower) set of tentacles act as olfactory organs. Both sets of tentacles are retractable in land snails. The eyes of most marine and freshwater snails are found at the base of the first set of tentacles.

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