Because tigers live in dense forests, they are hard to find, and counting them from the air or from vehicles does not work well. Scientists use motion-sensitive cameras in forests that let tigers take their own photographs. One research team in India reported in 2015 that each year it set up over 700 camera-trap stations covering 6,000 square kilometers, which produced over 15,000 images of tigers, leopards, dholes, elephants, deer and other animals. In Bangladesh, Smithsonian scientists collect field data on tigers, prey and mangrove habitat, including with camera-trap studies to estimate tiger populations.
Scientists can tell individual wild tigers apart by their stripe patterns, because no two tigers have the same stripes. Matching thousands of tiger photographs by eye is hard, so a pattern-matching program called ExtractCompare, developed by statistician Lex Hiby, extracts stripe patterns and shortlists the closest matches. Trained technicians then pick the tiger from the shortlist.
Tigers have more rods than cones in their eyes, which helps them see movement in the dark. Tigers also have a mirror-like layer at the back of the eye, called the tapetum lucidum, that makes their eyes glow at night when a light shines on them. A tiger's night vision is six times better than a human's, according to the San Diego Zoo, and tigers have binocular vision.
According to SeaWorld, a tiger's hearing is its sharpest sense. Its ears can rotate like a radar dish to find where sounds come from, such as the high-pitched sounds of prey in thick undergrowth. Amur tigers have large ears that are cup-shaped, which lets them catch and focus sounds. Tigers cannot purr continually. They roar instead, thanks to changes in the larynx and an elastic hyoid structure, and they also chuff, which is a non-threatening sound.
A 2022 IUCN assessment estimated between 3,726 and 5,578 wild tigers in Asia, with an average of 4,500. In that assessment, 3,140 of the 4,500 estimated wild tigers were adults. As of November 2026, WWF-UK says tigers occupy around 8% of their original range.
Newborn tiger cubs are blind and weigh 780 to 1,600 grams, and their ears open at 9 to 11 days. Weaning happens at 90 to 100 days, and from about 2 months old cubs follow their mother and begin to eat some solid food. A mother tiger begins teaching her cubs to hunt at about 3 months, and her cubs begin to take part in hunting trips at 5 to 6 months old. Young female tigers often settle near their mother's territory, while young males disperse farther from home. A female tiger reaches sexual maturity between age 3 and 4, and a male at about age 4 or 5.
Tigers keep several dens within their home range, often in dense plants, a cave or a hollow tree. Tigers mark their range with a musky scent sprayed on grass, trees and rocks, and with scrapes and claw marks. The size of a tiger's range depends on how much prey there is, and tigers mostly live alone.
Words to know
- tapetum: eye mirror
- individual: one by one
- assessment: a careful estimate
- weaning: ending milk feeding
