SHEEP

Sheep (Ovis aries) are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Although the name "sheep" applies to many species in the genus Ovis, in everyday usage it almost always refers to Ovis aries. Numbering a little over one billion, domestic sheep are also the most numerous species of sheep.

Sheep are most likely descended from the wild mouflon of Europe and Asia. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleece, meat (lamb, hogget or mutton) and milk. A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. Ovine meat is called lamb when from younger animals and mutton when from older ones. Sheep continue to be important for wool and meat today, and are also occasionally raised for pelts, as dairy animals, or as model organisms for science.

Sheep husbandry is practised throughout the majority of the inhabited world, and has been fundamental to many civilizations. In the modern era, Australia, New Zealand, the southern and central South American nations, and the British Isles are most closely associated with sheep production.

Sheep-raising has a large lexicon of unique terms which vary considerably by region and dialect. Use of the word sheep began in Middle English as a derivation of the Old English word scēap; it is both the singular and plural name for the animal. A group of sheep is called a flock, herd or mob. Adult female sheep are referred to as ewes, intact males as rams or occasionally tups, castrated males as wethers, and younger sheep as lambs. Many other specific terms for the various life stages of sheep exist, generally related to lambing, shearing, and age.

Being a key animal in the history of farming, sheep have a deeply entrenched place in human culture, and find representation in much modern language and symbology. As livestock, sheep are most-often associated with pastoral, Arcadian imagery. Sheep figure in many mythologies—such as the Golden Fleece—and major religions, especially the Abrahamic traditions. In both ancient and modern religious ritual, sheep are used as sacrificial animals.

Domestic sheep are relatively small ruminants, usually with a crimped hair called wool and often with horns forming a lateral spiral. Domestic sheep differ from their wild relatives and ancestors in several respects, having become uniquely neotenic as a result of selective breeding by humans.[1][2] A few primitive breeds of sheep retain some of the characteristics of their wild cousins, such as short tails. Depending on breed, domestic sheep may have no horns at all (polled), or horns in both sexes (as in wild sheep), or in males only. Most horned breeds have a single pair, but a few breeds may have several.[3]

Another trait unique to domestic sheep (as compared to wild ovines, not other livestock) is their wide variation in color. Wild sheep are largely variations of brown hues, and variation with species is extremely limited. Colors of domestic sheep range from pure white to dark chocolate brown and even spotted orpiebald.[4][5] Selection for easily dyeable white fleeces began early in sheep domestication, and as white wool is a dominant trait it spread quickly. However, colored sheep do appear in many modern breeds, and may even appear as a recessive trait in white flocks.[4][5] While white wool is desirable for large commercial markets, there is a niche market for colored fleeces, mostly for handspinning.[6] The nature of the fleece varies widely among the breeds, from dense and highly crimped, to long and hair-like. There is variation of wool type and quality even among members of the same flock, so wool classing is a step in the commercial processing of the fibre.

Suffolks are a medium wool, black-faced breed of meat sheep that make up 60% of the sheep population in the U.S.[7]

Depending on breed, sheep show a range of heights and weights. Their rate of growth and mature weight is a heritable trait that is often selected for in breeding.[7] Ewes typically weigh between 45 and 100 kilograms (99 and 220 lb), and rams between 45 and 160 kilograms (99 and 350 lb).[8] Mature sheep have 32 teeth. As with other ruminants, the front teeth in the lower jaw bite against a hard, toothless pad in the upper jaw. These are used to pick off vegetation, then the rear teeth grind it before it is swallowed. There are eight lower front teeth in ruminants, but there is some disagreement as to whether these are eight incisors, or six incisors and two incisor-shaped canines. This means that the dental formula for sheep is either I:0/4 C:0/0 P:3/3 M:3/3, or I:0/3 C:0/1 P:3/3 M:3/3.[9] There is a large toothless gap between the front "biting" teeth and the rear "grinding" teeth.

For the first few years of life it is possible to calculate the age of sheep from their front teeth, as a pair of milk teeth is replaced by larger adult teeth each year, the full set of eight adult front teeth being complete at about four years of age. The front teeth are then gradually lost as sheep age, making it harder for them to feed and hindering the health and productivity of the animal. For this reason, domestic sheep on normal pasture begin to slowly decline from four years on, and the average life expectancy of a sheep is 10 to 12 years, though some sheep may live as long as 20 years.[3][10][11]

Sheep have good hearing, and are sensitive to noise when being handled.[12] Sheep have horizontal slit-shaped pupils, possessing excellent peripheral vision; with visual fields of approximately 270° to 320°, sheep can see behind themselves without turning their heads.[6][13] However, sheep have poor depth perception; shadows and dips in the ground may cause sheep to baulk. In general, sheep have a tendency to move out of the dark and into well-lit areas,[14]and prefer to move uphill when disturbed. Sheep also have an excellent sense of smell, and, like 

GOAT

The domestic goat (Capra aegagrus hircus) is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of goat.

·         Goats are one of the oldest domesticated species. Goats have been used for their milk, meat, hair, and skins over much of the world. In the twentieth century they also gained in popularity as pets.

Female goats are referred to as does or nannies, intact males as bucks or billies; their offspring are kids. Note that many goat breeders prefer the terms "buck" and "doe" to "billy" and "nanny". Castrated males are wethers. Goat meat from younger animals is called kid or cabrito, and from older animals is sometimes called chevon, or in some areas “mutton”.

Diet:

Goats are reputed to be willing to eat almost anything, except tin cans and cardboard boxes. While goats will not actually eat inedible material, they are browsing animals, not grazers like cattle and sheep, and (coupled with their natural curiosity) will chew on and taste just about anything resembling plant matter in order to decide whether it is good to eat, including cardboard and paper labels from tin cans. Another possibility is that the goats are curious about the unusual smells of leftover food in discarded cans or boxes.

A domestic goat feeding in a field of capeweed, a weed which is toxic to most stock animals

Aside from sampling many things, goats are quite particular in what they actually consume, preferring to browse on the tips of woody shrubs and trees, as well as the occasional broad-leaved plant. However, it can fairly be said that their plant diet is extremely varied, and includes some species which are otherwise toxic. They will seldom consume soiled food or contaminated water unless facing starvation. This is one reason goat rearing is most often free ranging, since stall-fed goat rearing involves extensive upkeep and is seldom commercially viable.

Goats prefer to browse on shrubbery and weeds, more like deer than sheep, preferring them to grasses. Nightshade is poisonous; wilted fruit tree leaves can also kill goats. Silage (corn stalks) is not good for goats, but haylage can be used if consumed immediately after opening. Alfalfa is their favorite hay; fescueis the least palatable and least nutritious. Mold in a goat's feed can make it sick and possibly kill it. Goats should not be fed grass showing any signs of mold.

The digestive physiology of a very young kid (like the young of other ruminants) is essentially the same as that of a monogastric animal. Milk digestion begins in the abomasum, the milk having bypassed the rumen via closure of the reticular/esophageal groove during suckling. At birth, the rumen is undeveloped, but as the kid begins to consume solid feed, the rumen soon increases in size and in its capacity to absorb nutrients.

Reproduction:

In some climates, goats are able to breed at any time of the year. In temperate climates and among the Swiss breeds, the breeding season commences as the day length shortens, and ends in early spring. Does of any breed come into heat every 21 days for 2 to 48 hours. A doe in heat typically flags her tail often, stays near the buck if one is present, becomes more vocal, and may also show a decrease in appetite and milk production for the duration of the heat.

Bucks (intact males) of Swiss and northern breeds come into rut in the fall as with the doe's heat cycles. Rut is characterized by a decrease in appetite and obsessive interest in the does.

In addition to natural mating, artificial insemination has gained popularity among goat breeders, as it allows easy access to a wide variety of bloodlines. Gestation length is approximately 150 days. Twins are the usual result, with single and triplet births also common. Less frequent are litters of quadruplet, quintuplet, and even sextuplet kids. Birthing, known as kidding, generally occurs uneventfully. Right before kidding the doe will have a sunken area around the tail and hip. Also she will have heavy breathing, a worried look, become restless and show great display of affection for her keeper. The mother often eats the placenta, which gives her much needed nutrients, helps stanch her bleeding, and parallels the behavior of wild herbivores such as deer to reduce the lure of the birth scent for predators

Freshening (coming into milk production) occurs at kidding. Milk production varies with the breed, age, quality, and diet of the doe; dairy goats generally produce between 660 to 1,800 L (1,500 and 4,000 lb) of milk per 305 day lactation. On average, a good quality dairy doe will give at least 6 lb (2.7 l) of milk per day while she is in milk. A first time milker may produce less, or as much as 16 lb (7.3 l), or more of milk in exceptional cases. After the 305 day lactation, the doe will "dry off", typically after she has been bred. Occasionally, goats that have not been bred and are continuously milked will continue lactation beyond the typical 305 daysMeat, fibre, and pet breeds are not usually milked and simply produce enough for the kids until weaning.

Male lactation is also known to occur in goats.

RABBIT

Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world. There are eight different genera in the family classified as rabbits, including the European rabbit (Oryctolagus cuniculus), cottontail rabbits (genus Sylvilagus; 13 species), and the Amami rabbit (Pentalagus furnessi, an endangered species on Amami Ōshima, Japan). There are many other species of rabbit, and these, along with pikas andhares, make up the order Lagomorpha. The male is called a buck and the female is a doe; a young rabbit is a kitten or kit.

Habitat and range

Rabbit habitats include meadows, woods, forests, grasslands, deserts and wetlands. Rabbits live in groups, and the best known species, the European rabbit, lives in underground burrows, or rabbit holes. A group of burrows is called a warren.

More than half the world's rabbit population resides in North America. They are also native to southwestern Europe, Southeast Asia, Sumatra, some islands of Japan, and in parts of Africa and South America. They are not naturally found in most of Eurasia, where a number of species of hares are present. Rabbits first entered South America relatively recently, as part of the Great American Interchange. Much of the continent has just one species of rabbit, therapeutic, while most of South America's southern cone is without rabbits.

The European rabbit has been introduced to many places around the world

Characteristics and anatomy

The rabbit's long ears, which can be more than 10 cm (4 in) long, are probably an adaptation for detecting predators. They have large, powerful hind legs. The two front paws have 5 toes, the extra called the dewclaw. The hind feet have 4 toes. They are digitigrade animals; they move around on the tips of their toes. Wild rabbits do not differ much in their body proportions or stance, with full, egg-shaped bodies. Their size can range anywhere from 20 cm (8 in) in length and 0.4 kg in weight to 50 cm (20 in) and more than 2 kg. The fur is most commonly long and soft, with colors such as shades of brown, gray, and buff. The tail is a little plume of brownish fur (white on top for cottontails).

Because the rabbit's epiglottis is engaged over the soft palate except when swallowing, the rabbit is an obligate nasal breather. Rabbits have two sets of incisor teeth, one behind the other. This way they can be distinguished from rodents, with which they are often confused. Carl Linnaeus originally grouped rabbits and rodents under the class Glires; later, they were separated as the predominant opinion was that many of their similarities were a result of convergent evolution. However, recent DNA analysis and the discovery of a common ancestor has supported the view that they share a common lineage, and thus rabbits and rodents are now often referred to together as members of the superclass Glires.

Rabbits are hindgut digesters. This means that most of their digestion takes place in their large intestine and cecum. In rabbits the cecum is about 10 times bigger than the stomach and it along with the large intestine makes up roughly 40% of the rabbit's digestive tract. The unique musculature of the cecum allows the intestinal tract of the rabbit to separate fibrous material from more digestible material; the fibrous material is passed as feces, while the more nutritious material is encased in a mucous lining as a cecotrope. Cecotropes, sometimes called "night feces", are high in minerals,vitamins and proteins that are necessary to the rabbit's health. Rabbits eat these to meet their nutritional requirements; the mucous coating allows the nutrients to pass through the acidic stomach for digestion in the intestines. This process allows rabbits to extract the necessary nutrients from their food.

Rabbits are prey animals and are therefore constantly aware of their surroundings. If confronted by a potential threat, a rabbit may freeze and observe then warn others in the warren with powerful thumps on the ground. Rabbits have a remarkably wide field of vision, and a good deal of it is devoted to overhead scanning. They survive predation by burrowing, hopping away in a zig- zag motion, and, if captured, delivering powerful kicks with their hind legs. Their strong teeth allow them to eat and to bite in order to escape a struggle

Reproduction

Rabbits have a very rapid reproductive rate. The breeding season for most rabbits lasts 9 months, from February to October. In Australia & New Zealand breeding season is late July to late January. Normal gestation is about 30 days. The average size of the litter varies but is usually between 4 and 12 babies, with larger breeds having larger litters. A kit (baby rabbit) can be weaned at about 4 to 5 weeks of age. This means in one season a single female rabbit can produce as many as 800 children, grandchildren, and great-grandchildren. A doe is ready to breed at about 6 months of age, and a buck at about 7 months. Courtship and mating are very brief, lasting only 30 to 40 seconds. Courtship behavior involves licking, sniffing, and following the doe. Spraying urine is also a common sexual behavior. Female rabbits are reflex ovulators. The female rabbit also may or may not lose clumps of hair during the gestation period.

Ovulation begins 10 hours after mating. After mating, the female will make a nest or borough, and line the nest with fur from the dewlap, flanks, and belly. This behavior also exposes the nipples enabling her to better nurse the kits. Kits are altricial, which means they're born blind, naked, and helpless. Passive immunity (immunity acquired by transfer of antibodies or sensitized lymphocytes from another animal) is acquired by kits prior to birth via placental transfer. At 10 to 11 days after birth the baby rabbits' eyes will open and they will start eating on their own at around 14 days old.

Although born naked, they form a soft baby coat of hair within a few days. At the age of 5 to 6 weeks the soft baby coat is replaced with a pre-adult coat. At about 6 to 8 months of age this intermediate coat is replaced by the final adult coat, which is shed twice a year thereafter. Due to the nutritious nature of rabbit milk kits only need to be nursed for a few minutes once or twice a day.

The expected rabbit lifespan is about 9–12 years; the world's longest-lived was 18 years

CATTLE

Cattle (colloquially cows) are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius. Cattle are raised as livestock for meat (beef and veal), as dairy animals for milk and other dairy products, and as draft animals (pulling carts, plows and the like). Other products include leather and dung for manure or fuel. In some countries, such as India, cattle are sacred. It is estimated that there are 1.3 billion cattle in the world today. In 2009, cattle became the first livestock animal to have its genome mapped.

Word origin

Cattle did not originate as the term for bovine animals. It was borrowed from Old French catel, itself from Latin caput, head, and originally meant movablepersonal property, especially livestock of any kind, as opposed to real property (the land, to also include wild or small free-roaming animals such as chickens, which would be sold as part of the land). The word is closely related to "chattel" (a unit of personal property) and "capital" in the economic sense. The term replaced earlier Old English feoh "cattle, property" (cf. German: Vieh, Gothic: faihu).

The word cow came via Anglo-Saxon cū (plural cȳ), from Common Indo-European gʷōus (genitive gʷowes) = "a bovine animal", compare Persian Gâv, Sanskrit go, Welsh buwch.^[

In older English sources such as the King James Version of the Bible, "cattle" refers to livestock, as opposed to "deer" which refers to wildlife. "Wild cattle" may refer to feral cattle or to undomesticated species of the genus Boss. Today, when used without any other qualifier, the modern meaning of "cattle" is usually restricted to domesticated bovines

Anatomy

Cattle have one stomach with four compartments. They are the rumen, reticulum, omasum, and abomasum, with the rumen being the largest compartment. The reticulum, the smallest compartment, is known as the "honeycomb". Cattle sometimes consume metal objects which are deposited in the reticulum and irritation from the metal objects causes hardware disease. The omasum's main function is to absorb water and nutrients from the digestible feed. The omasum is known as the "many plies". The abomasum is like the human stomach; this is why it is known as the "true stomach".Cattle are ruminants, meaning that they have a digestive system that allows use of otherwise indigestible foods by regurgitating and rechewing them as "cud". The cud is then reswallowed and further digested by specialised microorganisms in the rumen. These microbes are primarily responsible for decomposingcellulose and other carbohydrates into volatile fatty acids that cattle use as their primary metabolic fuel. The microbes inside the rumen are also able to synthesize amino acids from non-protein nitrogenous sources, such as urea and ammonia. As these microbes reproduce in the rumen, older generations die and their carcasses continue on through the digestive tract. These carcasses are then partially digested by the cattle, allowing them to gain a high quality protein source. These features allow cattle to thrive on grasses and other vegetation.

The gestation period for a cow is nine months. A newborn calf weighs 25 to 45 kilograms (55 to 99 lb). The world record for the heaviest bull was 1,740 kilograms (3,840 lb), a Chaining named Donetto, when he was exhibited at the Arezzo show in 1955.The heaviest steer was eight year old ‘Old Ben’, a Shorthorn/Hereford cross weighing in at 2,140 kilograms (4,720 lb) in 1910. Steers are generally killed before reaching 750 kilograms (1,650 lb). Breeding stock usually live to about 15 years (occasionally as much as 25 years). The oldest recorded cow, Big Bertha, died at the age of 48 in 1993.

A common misconception about cattle (particularly bulls) is that they are enraged by the color red (something provocative is often said to be "like a red flag to a bull"). This is incorrect, as cattle are red-green color-blind. The myth arose from the use of red capes in the sport of bullfighting; in fact, two different capes are used. The capote is a large, flowing cape that is magenta and yellow. The more famous mullets is the smaller, red cape, used exclusively for the final, fatal segment of the fight. It is not the color of the cape that angers the bull, but rather the movement of the fabric that irritates the bull and incites it to charge.

Although cattle cannot distinguish red from green, they do have two kinds of color receptors in the cone cells in their retinas. Thus they are dichromatic, the same as most other mammals (including dogs, cats, horses and up to ten percent of male humans; see also color vision. ). They are able to distinguish some colors, particularly blue from yellow, in the same way as most other non-primate land mammals

HORSE

The horse (Equus ferus caballus) is a hooved (ungulate) mammal, a subspecies of the family Equipage. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today. Humans began to domesticate horses around 4000 BC, and their domestication is believed to have been widespread by 3000 BC. Although most horses today are domesticated, there are still endangered populations of the Przewalski's Horse, the only remaining true wild horse, as well as more common populations of feral horses which live in the wild but are descended from domesticated ancestors. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behaviour.

Horses' anatomy enables them to make use of speed to escape predators and they have a well-developed sense of balance and a strong fight-or-flightinstinct. Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down. Female horses, called mares, carry their young for approximately 11 months, and a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training under saddle or in harness between the ages of two and four. They reach full adult development by age five, and have an average lifespan of between 25 and 30 years.

Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance; "cold bloods", such as draft horses and some ponies, suitable for slow, heavy work; and "warm bloods", developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe. There are over 300 breeds of horses in the world today, developed for many different uses.

Horses and humans interact in a wide variety of sport competitions and non-competitive recreational pursuits, as well as in working activities such aspolice work, agriculture, entertainment, and therapy. Horses were historically used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control. Many products are derived from horses, including meat, milk, hide, hair, bone, and pharmaceuticals extracted from the urine of pregnant mares. Humans provide domesticated horses with food, water and shelter, as well as attention from specialists such as veterinarians and farriers.

Colors and markings

 

Horses exhibit a diverse array of coat color  and distinctive marking , described with a specialized vocabulary. Often, a horse is classified first by its coat color, before breed or sex. Horses of the same color may be distinguished from one another by white markings which, along with various spotting patterns, are inherited separately from coat color.

Many genes that create horse coat colors have been identified, although research continues to further identify factors that result in specific traits. One of the first genetic relationships to be understood was that between recessive "red) and dominant "black", which is controlled by the "red factor" or extension gene. Additional alleles control spotting, graying, suppression or dilution of color, and other effects that create the dozens of possible coat colors found in horses.

Chestnut, bay, and black are the basic equine coat colors. These colors are modified by at least ten other genes to create all other colors, including dilutions such as palomino and spotting patterns such as pinto. Horses which are white in coat color are often mislabeled as "white" horses. However, a horse that looks white is usually a middle-aged or older gray . Grays are born a darker shade, get lighter as they age, and usually have black skin underneath their white hair coat (with the exception of pink skin under white . The only horses properly called white are born with a white hair coat and have predominantly pink skin, a fairly rare occurrence There are no truly "albino" horses having both pink skin and red eyes

DONKEY

The donkey or ass, Equus africanus asinus is a domesticated member of the Equidae or horse family. The wild ancestor of the donkey is the African Wild Ass, E. africanus. In the western United States, a small donkey is sometimes called a burro (from the Spanish word for the animal).

A male donkey or ass is called a jack, a female a jenny, and offspring less than one year old, a foal (male: colt, female filly).

While different species of the Equities family can interbreed, offspring are almost always sterile. Nonetheless, horse/donkey hybrids are popular for their durability and vigor. A mule is the offspring of a jack (male donkey) and a mare (female horse). The much rarer successful mating of a male horse and a female donkey produces a hinny.

Asses were first domesticated around 3000 BC, approximately the same time as the horse, and have spread around the world. They continue to fill important roles in many places today and domesticated species are increasing in numbers, but the African wild ass and another relative, the Onsager, are endangered. As "beasts of burden" and companions, asses and donkeys have worked together with humans for millennia

Donkey hybrids

A male donkey (jack) can be crossed with a female horse to produce a mule. A male horse can be crossed with a female donkey (jennet or jenny) to produce a hinny. A female donkey in the UK is called a mare, or jenny.

Horse-donkey hybrids are almost always sterile because horses have 64 chromosomes whereas donkeys have 62, producing offspring with 63 chromosomes. Mules are much more common than hinnies. This is believed to be caused by two factors, the first being proven in cat hybrids, that when the chromosome count of the male is the higher, fertility rates drop (as in the case of stallion x jennet).^{[citation needed]} The lower progesterone production of the jenny may also lead to early embryonic loss. In addition, there are reasons not directly related to reproductive biology. Due to different mating behavior, jacks are often more willing to cover mares than stallions are to breed jennys. Further, mares are usually larger than jennys and thus have more room for the ensuing foal to grow in the womb, resulting in a larger animal at birth. It is commonly believed that mules are more easily handled and also physically stronger than hinnies, making them more desirable for breeders to produce, and it is unquestioned that mules are more common in total number.

The offspring of a zebra-donkey cross is called a zonkey, zeroed, zebrass, or zedonk; zebra mule is an older term, but still used in some regions today. The foregoing terms generally refer to hybrids produced by breeding a male zebra to a female donkey. Zebra hinny, zebret and zebrinny all refer to the cross of a female zebra with a male donkey. Zebrinnies are rarer than zedonkies because female zebras in captivity are most valuable when used to produce full-blooded zebras. There are not enough female zebras breeding in captivity to spare them for hybridizing; there is no such limitation on the number of female donkeys breeding

TIGER

The tiger (Panthera tigris), a member of the Fieldale family, is the largest of the four "big cats" in the genus Panthers.Native to much of eastern and southern Asia, the tiger is an apex predator and an obligate carnivore. Reaching up to 3.3 metres (11 ft) in total length, weighing up to 300 kilograms (660 pounds), and having canines up to 4 inches long. the larger tiger subspecies are comparable in size to the biggest extinct felids. Aside from their great bulk and power, their most recognisable feature is a pattern of dark vertical stripes that overlays near-white to reddish-orange fur, with lighter underparts. The most numerous tiger subspecies is the Bengal tiger while the largest is the Siberian tiger.

Tigers have a lifespan of 10–15 years in the wild, but can live longer than 20 years in captivity. They are highly adaptable and range from the Siberiantaiga to open grasslands and tropical mangrove swamps.

They are territorial and generally solitary animals, often requiring large contiguous areas of habitat that support their prey demands. This, coupled with the fact that they are indigenous to some of the more densely populated places on earth, has caused significant conflicts with humans. Three of the nine subspecies of modern tiger have gone extinct, and the remaining six are classified as endangered, some critically so. The primary direct causes arehabitat destruction, fragmentation and hunting.

Historically tigers have existed from Mesopotamia and the Caucasus throughout most of South and East Asia. Today the range of the species is radically reduced. While all surviving species are under formal protection, poaching, habitat destruction and inbreeding depression continue to threaten the tigers.

Tigers are among the most recognizable and popular of the world's charismatic megafauna. They have featured prominently in ancient mythology andfolklore, and continue to be depicted in modern films and literature. Tigers appear on many flags and coats of arms, as mascots for sporting teams, and as the national animal of several Asian nations, including India.

Physical characteristics

Tigers are easy to recognise. They typically have rusty-reddish to brown-rusty coats, a whitish medial and ventral area, a white "fringe" that surrounds the face, and stripes that vary from brown or gray to pure black. The form and density of stripes differs between subspecies (as well as the ground coloration of the fur; for instance, Siberian tigers are usually paler than other tiger subspecies), but most tigers have over 100 stripes.

The pattern of stripes is unique to each animal, and thus could potentially be used to identify individuals, much in the same way that fingerprints are used to identify humans. This is not, however, a preferred method of identification, due to the difficulty of recording the stripe pattern of a wild tiger. It seems likely that the function of stripes is camouflage, serving to help tigers conceal themselves amongst the dappled shadows and long grass of their environment as they stalk their prey. The stripe pattern is also found on the skin of the tiger. If a tiger were to be shaved, its distinctive camouflage pattern would be preserved.

Like other big cats, tigers have a white spot on the backs of their ears. These spots, called ocelot, serve a social function, by communicating the animal's mental state to conspecifics in the gloom of dense forest or in tall grass.

Tigers have the additional distinction of being the heaviest cats found in the wild.^] They also have powerfully built legs and shoulders, with the result that they, like lions, have the ability to pull down prey substantially heavier than themselves. However, the subspecies differ markedly in size, tending to increase proportionally with latitude, as predicted by Bergmann's Rule.

Large male Siberian Tigers (Panthera tigris altaica) can reach a total length of 3.5 m "over curves" (3.3 m. "between pegs") and a weight of 306 kilograms,. This is considerably larger than the sizes reached by island-dwelling tigers such as the Sumatran, the smallest living subspecies, with a body weight of only 75–140 kg. Tigresses are smaller than the males in each subspecies, although the size difference between male and female tigers tends to be more pronounced in the larger subspecies of tiger, with males weighing up to 1.7 times more than the females. In addition, male tigers have wider forepaw pads than females. Biologists use this difference to determine gender based on tiger tracks.^] The skull of the tiger is very similar to that of the lion, though the frontal region is usually not as depressed or flattened, with a slightly longer postorbital region. The skull of a lion has broader nasal openings. However, due to the amount of skull variation in the two species, usually, only the structure of the lower jaw can be used as a reliable indicator of species.Tigers have round pupils and yellow irises (except for the blue eyes of white tigers). Due to a retinal adaptation that reflects light back to the retina, the night vision of tigers is six times better than that of humans.