Leakey and the National Geographic Society helped Galdikas set up a research camp in Borneo to study orangutans. Although she grew up in Toronto and spends several months a year teaching in Vancouver at SFU, Galdikas has been living in the rainforest among the orangutans for the last 23 years. The tropical rainforest is one of the most stable ecosystems on the planet. A huge variety of plants and animals thrive there, and nothing has changed for millions of years. This is why the common ancestor for all apes including humans may have been somewhat like an orangutan.
Orangutans have no serious predators except humans.
Their dietary knowledge of the irregular fruiting patterns of tropical plants highlights their intelligence. It also explains their solitary lifestyle and the eight-year interval between births. A big animal needs a lot of foraging territory without too many others around. Structural Brachiators Orangutans are structural brachiators which means they are built to swing from branches with their upper limbs, but they have become too heavy to move quickly like this. Adult orangutans are the largest tree-dwelling animals on earth, averaging about 100 kilograms for males.