Vegetarian Turned Meat Eater: The Curious Case of Sumatran Orangutans

We always think of orangutans as placid, complacent animals. Science documentaries often showcase the animal chomping on vegetation and fruits, and occasionally on insects and eggs.

Some great apes, however, have developed a liking for meat. Jane Goodall first documented the meat-eating habit of chimps in the early 1960s. Since then, reports of meat-eating great apes have been made, and we can no longer see these animals as strictly vegetarian. 
Recently, the docile omnivore has been spotted dining on slow loris, a small primate dubbed the world's cutest animal.

Image: cute-n-tiny.com

A group of researchers studying orangutans in Ketambe Research Station in Sumatra, Indonesia observed in 2007, a female orangutans knocking a slow loris out of the tree and killing it with a bite to the head.

Madeleine Hardus and her colleagues observed Yet, a female orangutan and Yeni, her dependent infant for 38 days, during which three cases of slow loris eating occurred. The adult orangutan slapped the slow-moving loris, knocking it unconscious, and then captured and killed it with a bite to the skull.

Image: newscientist.com

Orangutans may not be as agile as chimps, but they do not have to be, because slow lorises, as their name suggests, are slow-moving. But the saliva of the slow loris is toxic, which explains why the orangutan knocked the slow loris unconscious before killing it.

Image: motherjones.com

Meat-eating, however, is still a rarity among orangutans. Hardus and her colleagues have thus far observed three cases, bringing the total to nine. The researchers also found that the hunting occurred when fruit was scarce, which is different from chimps, who hunt even when fruits are abundant.

Malcolm

info:

Behavioral, Ecological, and Evolutionary Aspects of Meat-Eating by Sumatran Orangutans (Pongo abelii). Madeleine E. Hardus et al. American Journal of Primatology, vol 43, p 159.