Bengal Tigers

Tiger

The tiger (Panthera tigris) is the largest cat species, reaching a total body length of up to 3.38 m (11.1 ft) over curves and exceptionally weighing up to 388.7 kg (857 lb) in the wild. Its most recognisable feature is a pattern of dark vertical stripes on reddish-orange fur with a lighter underside. The species is classified in the genus Panthera with the lion, leopard, jaguar and snow leopard. Tigers are apex predators, primarily preying on ungulates such as deer and bovids. They are territorial and generally solitary but social animals, often requiring large contiguous areas of habitat that support their prey requirements. 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.

Tigers once ranged widely across Asia, from Turkey in the west to the eastern coast of Russia. Over the past 100 years, they have lost 93% of their historic range, and have been extirpated from southwest and central Asia, from the islands of Java and Bali, and from large areas of Southeast and Eastern Asia. Today, they range from the Siberian taiga to open grasslands and tropical mangrove swamps. The remaining six tiger subspecies have been classified as endangered by IUCN. The global population in the wild is estimated to number between 3,062 and 3,948 individuals, down from around 100,000 at the start of the 20th century, with most remaining populations occurring in small pockets isolated from each other, of which about 2,000 exist on the Indian subcontinent.[4] Major reasons for population decline include habitat destruction, habitat fragmentation and poaching. The extent of area occupied by tigers is estimated at less than 1,184,911 km2 (457,497 sq mi), a 41% decline from the area estimated in the mid-1990s.

Tigers are among the most recognisable and popular of the world’s charismatic megafauna. They have featured prominently in ancient mythology and folklore, and continue to be depicted in modern films and literature. They appear on many flags, coats of arms, and as mascots for sporting teams. The tiger is the national animal of Bangladesh, India, Vietnam, Malaysia and South Korea.

Taxonomy and etymology
In 1758, Linnaeus first described the species in his work Systema Naturae under the scientific name Felis tigris.[3] In 1929, the British taxonomist Reginald Innes Pocock subordinated the species under the genus Panthera using the scientific name Panthera tigris.[5]

The word Panthera is probably of Oriental origin and retraceable to the Ancient Greek word panther, the Latin word panthera, the Old French word pantere, most likely meaning “the yellowish animal”, or from pandarah meaning whitish-yellow. The derivation from Greek pan- (“all”) and ther (“beast”) may be folk etymology.[6]

The specific epithet, tigris, as well as the common name, tiger, come from the Middle English tigre and the Old English tigras (a plural word), both used for the animal.[7] These derive from the Old French tigre, itself a derivative of the Latin word tigris and the Greek word tigris. The original source may have been the Persian tigra meaning pointed or sharp and the Avestan tigrhi meaning an arrow, perhaps referring to the speed with which a tiger launches itself at its prey.[8]

Evolution
The tiger’s closest living relatives are the lion, leopard and jaguar, all of which are classified under the genus Panthera. A 2010 genetic analysis shows the tiger began evolving 3.2 million years ago, and it may be more closely related to the snow leopard than other Panthera species.[9][10] The oldest remains of an extinct tiger relative, called Panthera zdanskyi or the Longdan tiger, have been found in the Gansu province of northwestern China. This species is considered to be a sister taxon to the extant tiger and lived about 2 million years ago, at the beginning of the Pleistocene. It was smaller than the modern tiger, being the size of a jaguar, and probably did not have the same coat pattern. Despite being considered more “primitive”, the Longdan tiger was functionally and possibly ecologically similar to its modern cousin. As Panthera zdanskyi lived in northwestern China, that may have been where the tiger lineage originated. Tigers grew in size, possibly in response to adaptive radiations of prey species like deer and bovids which may have occurred in Southeast Asia during the early Pleistocene.[11]

The earliest fossils of true tigers are from Java, and are between 1.6 and 1.8 million years old. Distinct fossils are known from the early and middle Pleistocene deposits in China and Sumatra. A subspecies called the Trinil tiger (Panthera tigris trinilensis) lived about 1.2 million years ago and is known from fossils found at Trinil in Java.[12]

Tigers first reached India and northern Asia in the late Pleistocene, reaching eastern Beringia (but not the American Continent), Japan, and Sakhalin. Fossils found in Japan indicate the local tigers were, like the surviving island subspecies, smaller than the mainland forms, an example of insular dwarfism. Until the Holocene, tigers also lived in Borneo, as well as on the island of Palawan in the Philippines.[13]

The tiger’s full genome sequence was published in 2013. It and other cat genomes were found to have similar repeat composition and an appreciably conserved synteny.[14]

Subspecies
There are 10 recognized tiger subspecies. One, the Trinil, became extinct in prehistoric times. The remaining subspecies all survived at least into the mid-20th century; three of these are also considered extinct. Their historical range in Bangladesh, Siberia, Iran, Afghanistan, India, China, and southeast Asia, including three Indonesian islands, is severely diminished today