Over the past century, the number of wild tigers has plummeted by over 95% and sadly, there are more tigers in captivity in the US than are left in the wild. There's now estimated to be nearly 3,900 wild tigers. The tiger is officially classed as endangered by the IUCN. Each tiger has a unique set of stripes – like a fingerprint – and this helps WWF identify individuals in the wild. Animal adoptions give a huge boost to WWF's work. They help fund projects to work with local communities to monitor tiger movements, reduce poaching and help people live alongside wild tigers.