Apes’ insect buffet

Fruit and leaves are known to be the main component to the diet of great apes such as gorilla, chimpanzee, bonobo, orangutan and gibbon. However, these non-human primates have also been known to feast on insects, but this behavior has been difficult to understand and to track in the wild. To this date insect consumption by apes has been reported based on direct observations or trail signs in feces. 

Now, a group of researchers of Aix-Marseille Université in Marseilles and the University of Montpellier have gained further insight into apes’ insect-eating habits by using DNA Barcoding.

The researchers analyzed fecal samples from gorillas, bonobos, and chimpanzees and they were able to identify 106 different species from 32 families of insects, including flies, beetles, butterflies, moths, mosquitoes, and termites. Surprisingly, they did not find any ant or bee species within the samples, although they noted that could have been a result of DNA degradation in primate guts.

Compared with behavioral observations and/or analysis of trail signs in ape feces, we found many previously unknown insect families that are consumed by African great apes. Many insects, such as species in the orders Coleoptera and Lepidoptera or caterpillars detected in this study have strong associations with plants. Some of these insect species, such as member of family Chrysomelidae, feed on different plant parts. Consequently, they could be eaten incidentally (secondary predation) when African great apes feed on plants. Thus, one advantage of using a molecular approach to examine insects consumed is the inclusion of those consumed via secondary predation. These species may not have been otherwise detected through classical approaches, but they are still components of the diet that have nutritional value. These indirectly eaten insects may also contribute to an understanding of the feeding ecology and foraging strategy of a species.