Orang utans crush tough foliage and hard-shelled nuts with their strong teeth and jaws. Outside of their native ranges, they can be differentiated only through chromosomal or DNA analysis. Orang utans are Asia's largest primates. Males are about twice the size of females, standing four and a half feet tall and weighing 130 to 200 pounds. Females stand about two and a half feet tall and weigh 90 to 110 pounds.
Zoo animals are often heavier.
Orang utans live in tropical rainforests, including hill forests and swamp forests. Orang utans feed primarily on forest fruits, including durians, jackfruits, lychees, mangos, and figs. Leaves and shoots make up the remainder of their diet, supplemented occasionally by small animals, tree bark, and soils rich in minerals. Researchers have documented more than 400 different foods eaten by wild orang utans. Male orang utans establish home ranges that embrace those of several females.