Orangutans cannot swim, but that has not prevented them from enjoying fishes for meals which they catch using their long limbs and a little assistance from sharp sticks. This has been found by anthropologist Anne Russon who spent over two years observing the animals.
Anne who is from York University in Toronto researched on Orangutans living in Indonesian Borneo Islands and reported her observations at a meeting of the American Association of Physical Anthropologists.
She found that although the apes could not swim, they used a little enterprise to jab at catfishes with a stick in small ponds and scavenge on the ones that washed ashore.
She said, “If orangutans can do this, then early hominids could also have practiced tool-assisted fishing.”
Anne and her team observed the orangutans of Borneo from 2004 till 2006. In 2007 they filled a pond with catfishes and observed the apes’ behavior recording videos of their visit to the pond in a day.
They found that seventeen times the apes grabbed fishes from the pond, and ate them. They also used sticks to hit the prey.
Interestingly, Anne also found that while orangutans preferred to fish alone, there was a pair that caught the catfish together. She noticed that while one of the apes was fishing, the other stood and watched, surely trying to learn the trick of catching fishes from its mate.
The finding, according to other anthropologists, points to the fact that hominids – human ancestors, ate meat, including fish, before the emergence of the Homo genus around 2.5 million years ago. Earlier the experts had always believed that meat eating traits developed later in the homo species and led to brain expansion.
Fish contains more fatty acids needed for brain growth than meat, and archeological evidence show that members of the homo genus did eat fish.
Fishing, according to Anne is not common among primates. Some chimpanzees have been seen fishing and also certain macaque and baboon species that swim well. Orangutans, however, cannot swim.
Anne said. “They sink like stones in the water.”
“Orangutans’ determined fishing efforts underscore the nutritional importance of marine foods for apes in general, not just people”, she added.
The act of fishing by these apes may have started out accidentally and then became a thought out intentional process, feels the anthropologist. She also stresses that in human ancestors known as the hominids too the process might have been the same – moving from opportunistic fish gathering to deliberate fishing.
