Anatomy and biology
Though similar to a lion's, the lower jaw structure is a reliable indicator of the species.
Tigers have muscular bodies with powerful forelimbs, large heads and long tails. The pelage is dense and heavy; colouration varies between shades of orange and brown with white ventral areas and distinctive vertical black stripes, whose patterns are unique to each individual.[22][57] Their function is likely for camouflage in vegetation such as long grass with strong vertical patterns of light and shade.[57][58] The tiger is one of only a few striped cat species; it is not known why spotted patterns and rosettes are the more common camouflage pattern among felids.[59] The tiger's stripes are also found on the skin, so that if it were to be shaved, its distinctive coat pattern would still be visible. They have a mane-like heavy growth of fur around the neck and jaws and long whiskers, especially in males. The pupils are circular with yellow irises. The small, rounded ears have a prominent white spot on the back, surrounded by black.[22] These false "eyespots", called ocelli, apparently play an important role in intraspecies communication.[60]
The skull is 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 variation in skulls of the two species, the structure of the lower jaw is a more reliable indicator of species.[61] The tiger also has fairly stout teeth; the somewhat curved canines are the longest among living felids with a crown height of up to 90 mm (3.5 in).[22]
The oldest recorded captive tiger lived for 26 years. A wild specimen, having no natural predators, could in theory live to a comparable age.