The tiger (Panthera tigris) is a mammal of the Felidae family, the largest of four "big cats" in the Panthera genus.Native to the mainland of Asia, the tiger is an apex predator and the largest feline species in the world,comparable in size to the biggest fossil felids.The Bengal Tiger is the most common subspecies of tiger, constituting approximately 80% of the entire tiger population, and is found in India, Bangladesh, Bhutan, Myanmar and Nepal. It has disappeared from much of its former distribution including the Caucasus, Java and Bali.
The tiger is an endangered species, with the majority of the world's tigers now living in captivity.Several subspecies are extinct and others critically endangered. Tigers have featured in ancient mythologies and folklore, and continue to be depicted in modern films and literature, as well as appearing on flags, coats of arms and as mascots for sporting teams. It is the national animal of India.
Naming and etymology
The word "tiger" is taken from the Greek word "tigris", which itself is derived "possibly from an Iranian source."In American English, "Tigress" was first recorded in 1611. "Tiger's-eye" is a name for a golden-brown striped, chatoyant, fibrous variety of quartz used as a semi-precious gemstone. It was one of the many species originally described, as Felis tigris, by Linnaeus in his 18th century work, Systema Naturae.The generic component of its scientific designation, Panthera tigris, is often presumed to derive from Greek pan- ("all") and ther ("beast"), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of East Asian origin, meaning "the yellowish animal," or "whitish-yellow".
Taxonomy and evolution
The Tiger is uncommon in the fossil record, which is why its evolution remains partly unclear. The oldest remains of a tiger like cat, called Panthera palaeosinensis have been found in China and Java. This species occurred about 2 million years ago at the beginning of the pleistocene and was smaller than a tiger. Early true tiger fossils stem from Java and are between 1.6 and 1.8 million years old. Distinct fossils from the early and middle Pleistocene were discovered in deposits from China, Sumatra and Java. A subspecies called Trinil tiger (Panthera tigris trinilensis) for example occurred about 1.2 million years ago and was found at the locality of Trinil, Java, Indonesia.In India, and northern Asia the tiger appears for the first time in the late pleistocene. Fossil tigers were also found in eastern Beringia (but not on the American Continent) and Sachalin island. Tiger fossils of the late Pleistocene have also turned up in Japan. These fossils indicate that the Japanese tiger was not bigger than the island subspecies of tigers of recent ages. This may be due to the phenomenon in which body size is related to environmental space (see island dwarfism), or in the case of a large predator like a tiger, availability of prey. Until the Holocene tigers occurred also in Borneo, where it is not present today.
Physical characteristics
Tigers are the heaviest cats found in the wild, but the subspecies differ strongly 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 and a weight of 306 kg.Apart from those exceptional large individuals, male Siberian tigers usually have a head and body length of 190–220 cm and an average weight of 227 kg(The tail of a tiger is 60–110 cm long.) The heaviest Indian Tiger (P. t. tigris) mentioned in literature weighed 389 kg (857 lb)[citation needed], the heaviest siberian tiger 384 kg, but according to Mazak these giants are not confirmed via reliable references.Females are smaller, those of the Siberian or Indian subspecies weigh only between 100 and 181 kg. Isle tigers like the sumatran subspecies (P. t. sumatrae) are much smaller than mainland tigers and weigh usually only 100–140 kg in males and 75–110 kg in females. The extinct Bali Tiger (P. t. balica) was even smaller with a weight of 90–100 kg in males and 65–80 kg in females.
Tigers have rusty-reddish to brown-rusty coats, a fair (whitish) medial and ventral area and stripes that vary from brown or hay to pure black. The form and density of stripes differs between subspecies, but most tigers have in excess of 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 as fingerprints are used to identify people. 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 hide these animals from their prey. The stripe pattern is found on a tiger's skin and if shaved, its distinctive camouflage pattern would be preserved.
Like most cats, tigers are believed to have some degree of colour vision.
Biology and behaviour
Adult tigers are fiercely territorial. The size of a tiger's home range mainly depends on prey abundance, and, in the case of male tigers, on access to females. A tigress may have a territory of 20 km² while the territories of males are much larger, covering 60–100 km². While females can at times be aggressive towards other females, their territories can overlap and they do tolerate each other. Males, however, are usually intolerant of other males within their territory. Because of their aggressive nature, territorial disputes can be violent, and may end in the death of one of the males. To identify his territory, the male marks trees by spraying urine and anal gland secretions on trees as well as by marking trails with scat. Males show a grimacing face, called the Flehmen response, when identifying a female's reproductive condition by sniffing their urine markings.
Male tigers can mingle easily with females in their territories and will even share kills. George Schaller observed a male tiger share a kill with two females and four cubs. Females are often reluctant to let males near their cubs, but Schaller saw that these females made no effort to protect or keep their cubs from the male. This suggests that the male might have been the father of the cubs. In contrast to male lions, male tigers will allow the females and cubs to feed on the kill first. Females will also share kills, even more so than the males. They are also much more tolerant of sharing kills with individuals of the same sex.
Tigers have been studied in the wild using a variety of techniques. The populations of tigers were estimated in the past using plaster casts of their pugmarks. In recent times, camera trapping has been used instead. Newer techniques based on DNA from their scat are also being evaluated. Radio collaring has also been a popular approach to tracking them for study in the wild.
Hunting and diet
In the wild, tigers mostly feed on larger and medium sized animals. Sambar, gaur, water buffalo, chital, wild boar and nilgai are the tiger's favored prey in India. In Siberia the main prey species are Mandchurian elk, wild boar, sika deer, roe deer and musk deer. In Sumatra; rusa deer, wild boar and Malayan tapir are preyed on. Like many predators, they are opportunistic and will eat much smaller prey such as as monkeys, peacocks, hares and fish.
They also may kill such formidable predators as dholes, leopards, and pythons. Tigers have been known to kill even crocodiles on occasion,[33][34][35] although predation is rare and the predators typically avoid one another. Siberian tigers and brown bears are a serious threat to each other and usually avoid confrotation; however, tigers will kill bear cubs and even some adults on occasion. Bears (Asiatic black bears and brown bears) make up 5-8% of the tigers diet in the Russian Far East. [24] Sloth bears are quite aggressive and will sometimes drive young tigers away from their kills although the opposite happens as well and in some cases Indian tigers even prey on sloth bears.[24]
Adult elephants are too dangerous to tigers to serve as common prey, but conflicts between elephants and tigers do sometimes take place. A case where a tiger killed an adult female Indian rhino has been observed.[36] Young elephant and rhino calves are occasionally taken.
Tigers sometimes prey on domestic animals such as dogs, cows, horses and donkeys. These individuals are termed cattle-lifters or cattle-killers in contrast to typical game-killers. Especially old and injured tigers have been known to attack humans and are then termed as man-eaters, which often leads to them being captured, shot or poisoned. The Sundarbans mangrove swamps of Bengal, where some healthy tigers have been known to hunt humans, have had a higher incidence of man-eaters.
Hunting methods
Tigers hunt alone and prefer medium to large sized herbivores. They ambush their prey as other cats do, overpowering them from any angle, using their body size and strength to knock large prey off balance. Even with their great masses, tigers can reach speeds of about 49-65 km/h (35-40 mph). Tigers prefer to bite the throats of large prey and use their muscled forelimbs to hold onto the prey, bringing it to the ground. The tiger remains latched onto the neck until its prey dies. With small prey, the tiger bites the nape, often breaking the spinal cord, piercing the windpipe, or severing the jugular vein or carotid artery. The prey is killed instantly.
In the wild, tigers can leap as high as 5 m (16 ft) and as far as 9–10 m (30–33 ft), making them one of the highest-jumping mammals (just slightly behind cougars in jumping ability).
They have been reported to carry domestic livestock weighing 50 kg (110 lb) while easily jumping over fences 2 m (6 ft 6 in) high. Their heavily muscled forelimbs are used to hold tightly onto the prey and to avoid being dislodged, especially by large prey such as gaurs. Gaurs and water buffalos weighing over a ton have been killed by tigers weighing about a sixth as much. The combination of claws and power behind a tiger's paws enables it to kill an adult human with one swipe.
Reproduction
A female is only receptive for a few days and mating is frequent during that time period. A pair will copulate frequently and noisily, like other cats. The gestation period is 103 days and 3–4 cubs of about 1 kg (2 lb) each are born. The females rear them alone. Wandering male tigers may kill cubs to make the female receptive. At 8 weeks, the cubs are ready to follow their mother out of the den. The cubs become independent around 18 months of age, but it is not until they are around 2–2½ years old that they leave their mother. The cubs reach sexual maturity by 3–4 years of age. The female tigers generally own territory near their mother, while males tend to wander in search of territory, which they acquire by fighting and eliminating another male. Over the course of her life, a female tiger will give birth to an approximately equal number of male and female cubs. Tigers breed well in captivity, and the captive population in the United States may rival the wild population of the world.
Habitat
Tigers are found in a variety of habitats, from tropical rainforests and boreal forests to dry savannas as they are found in Ranthambore National Park. The Caspian tiger was also found in steppes and mountainous areas. Compared to the lion, the tiger prefers more dense vegetation, for which its camouflage is ideally suited, and where a single predator is not at a disadvantage compared to a pride. Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers.
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