RIO DE JANEIRO, BRAZIL – Dutch primatologist Carel van Schaik was able to observe an orang-utan for the first time in 1994 using tools it had developed in order to feed itself.
During an expedition to Gunung Leuser National Park in northwestern Sumatra, the expert noticed that some specimens used sticks to open a type of fruit with sweet and nutritious pulp, but which has thorns that can embed in the skin and cause great pain.
From an anthropological point of view, the use of tools represents a cultural aspect, since the whole group takes part in behavior that has developed over time. One important thing to clarify is that, until now, only the orang-utans of Sumatra had been observed using tools, not the orang-utans of Borneo.
The male orang-utan was photographed clinging tightly to a branch, suspended above the water, vigorously waving a spear into the water trying to pierce a fish with its tip.
The extraordinary picture was taken on Kaja Island in Borneo.
Although the method required too much skill for it to master, it was later able to improvise using the stick to catch fish that were trapped in local fishing lines.
Other primates have been seen using tools to feed themselves. In 2018, researchers found a group of capuchin monkeys from Jacarón Island in Panama, that has also evolved in the same direction.