Crab-eating chimps intrigue Swiss scientists

Chimps are mainly vegetarian, but sometimes eat meat... or crabs. Keystone

Researchers from the University of Zurich have shown for the first time that chimpanzees catch and eat crabs. They say this could even teach us about human evolution.

Chimpanzees, our closest living relatives, are mainly vegetarian but occasionally eat meat. Now the Zurich researchers have discovered chimpanzees in the rainforest of Guinea’s Nimba Mountains  that consume freshwater crabs year-round. The chimpanzees search for crabs in shallow streams by scratching and churning up the riverbed with their fingers, according to a press releaseExternal link.

 “Our study is the first evidence showing that non-human apes regularly catch and eat aquatic fauna,” says Kathelijne Koops, researcher at the University of Zurich Department of Anthropology.  The chimpanzees ate crabs irrespective of whether ripe fruit was available as an alternative.

“Female chimpanzees and their offspring fished for crabs more often and for longer than adult males, which we had not expected,” says Koops. A possible explanation for this finding may be that crabs provide essential fatty acids, as well as micronutrients such as sodium and calcium, which are crucial for maternal and infant health.

The findings on chimpanzees may contribute to our understanding of why aquatic fauna became more and more important as a source of nutrition in the course of human evolution. It is thought that as long as 1.95 million years ago, ancestors of Homo sapiens consumed turtles, crocodiles and fish. Regular consumption of these types of aquatic fauna with their rich nutritional value is thought to have facilitated the growth of the developing brain in early man.