The World Wildlife Fund (WWF) lists Bornean orangutans as endangered. About 41,000 live in Borneo, while there are far less Sumatran orangutans---or about 7,500---still in the wild. The Sumatran subspecies is listed by the WWF as critically endangered.
The WWF explains:
The two species of orangutan, Bornean and Sumatran, differ a little in appearance and behavior. While both have shaggy reddish fur, Sumatran orangutans have longer facial hair. Sumatran orangutans are reported to have closer social bonds than their Bornean cousins. Bornean orangutans are more likely to descend from the trees to move around on the ground. Both species have experienced sharp population declines. A century ago there were probably more than 230,000 orangutans in total, but the Bornean orangutan is now estimated to number about 45,000-69,000 (Endangered) and the Sumatran about 7,500 (Critically Endangered).
Orangutans can weigh up to 200 pounds.
They are the largest arboreal mammal, spending much of their time in trees, the WWF says.
