Chimpanzees have a mainly vegetarian diet, but do occasionally eat meat. Researchers at the University of Zurich have now shown for the first time that chimpanzees also eat crabs. In the rainforest of Guinea, the researchers observed how chimpanzees regularly fish for crabs.
“Our study is the first evidence showing that non-human apes regularly catch and eat aquatic fauna,” says Kathelijne Koops, researcher at the Department of Anthropology at the University of Zurich. She and her team discovered that chimpanzees in the rainforest of the Nimba Mountains in Guinea consumed fresh-water crabs year-round. The chimpanzees searched for crabs in shallow streams in the mountainous rainforest region by scratching and churning up the riverbed with their fingers.
The chimpanzees ate crabs irrespective of whether ripe fruit was available as an alternative. Surprisingly there was no correlation between the crab-fishing activity and the amount of monthly rainfall. The rate of crab-fishing also remained the same in the dry and in the rainy seasons: Even in the dry season there was enough water in the streams to provide a habitat for crabs. The chimpanzees, however, fished more often for crabs when they were eating fewer ants, which would indicate that crabs and ants have a similar nutritional value for the chimpanzees.
Read more at University of Zurich
Image: Chimpanzee fishing for crabs. (Credit: Kathelijne Koops)