A 2018 study in Current Biology sequenced whole genomes from 32 tiger specimens. It found six clades that match the living subspecies. A 2013 study compared the genomes of an Amur tiger, a white Bengal tiger, an African lion, a white African lion and a snow leopard. It found genetic signatures that may reflect adaptations to the big cats' hypercarnivorous (mostly meat) diet and muscle strength. Researchers also compared an Amur tiger genome with the genomes of a lion and a snow leopard, both in the genus Panthera.
There are eight recognized subspecies of Panthera tigris, according to Animal Diversity Web, while the San Diego Zoo and the Smithsonian's National Zoo count six living subspecies. The Amur tiger is the largest kind of tiger, and the Sumatran tiger is the smallest kind of tiger. Indochinese male tigers are smaller than Siberian tigers in body size, but have the longest skull of any tiger subspecies, 319 to 365 mm.
Researchers at the University of Bristol used machine learning and image processing to embed targets in two different environments. They found the colour that would either minimise or maximise how visible a target is. Dark stripes on a pale background break up a tiger's outline as it waits for prey to come near. Animal Diversity Web says the spots on the backs of a tiger's ears may also be used to communicate with other tigers, and so may its stripe pattern.
In 2010 in St. Petersburg, leaders of 13 tiger-range countries met with scientists to create a comprehensive strategy to save tigers. In 2010 the world set a goal of doubling tiger numbers, or reaching at least 6,000 by 2022. In July 2022 Panthera said the goal had been missed and that range states would set a new 12-year recovery plan at a second Global Tiger Summit. A 2020 award was set up for sites that had doubled their wild tigers since 2010.
Smithsonian efforts to save tigers began in 1972 with the Smithsonian-Nepal Tiger Ecology Project. In 2008 the Smithsonian joined the World Bank Group and the Global Environmental Facility to launch the Global Tiger Initiative. Rangers in tiger-range countries are trained in SMART patrolling, a Spatial Monitoring and Report Tool. Panthera says its Tigers Forever program monitors tigers and their prey in critical sites across five tiger range countries.
The 2022 IUCN assessment said South Asia held 76% of the global tiger population and that its tigers were gaining numbers, particularly in India and Nepal. It said that in Northeast Asia tiger numbers were relatively stable in Russia and likely increasing along the border with China. It also said Southeast Asia's tigers had fared worst. They had been lost from Cambodia, Lao PDR and Vietnam since the turn of the century. As of November 2026, Panthera says that with partners it helped more than triple the number of tigers detected in Manas National Park, India, a former conflict area where the tiger population was nearly poached to local extinction.
Female Indian tigers have home ranges of 200 to 1000 square kilometers, and a male's home range averages 2 to 15 times larger. Young female tigers often settle near their mother's territory, while young males disperse farther from home. Tigers can share home ranges peacefully or wander with no home range at all.
Words to know
- genomes: full gene sets
- clades: family branches
- specimens: sample animals
- patrolling: watching rounds
