There are two species of orangutans: Bornean, ones that prefer the ground over the trees, and Sumatran, which have longer facial hair and develop closer bonds with each other. A century ago, their global population was more than 230,000. Now there are between 45,000 and 69,000 Bornean (endangered status) and only 7,500 Sumatran (critically endangered status).
That’s right, even squirrels are endangered, specifically the San Joaquin antelope ground squirrel. Native to California, these guys have been disappearing since 1979 on account of the construction and human developments going through their habitat. Their total population is unknown, but it could be anywhere between 124,000 and 413,000.
All six tiger species are endangered, with Sumatran and South China tigers at a critically endangered status. The main reasons for their population decline are poaching and destroyed habitats, as humans clear forests to gather timber and build roadways. Only about 3,890 tigers currently live in the wild.