Leaf swallowing and parasite expulsion in Khao Yai white ‐handed gibbons (Hylobates lar), the first report in an Asian ape species

We present the first evidence of leaf swallowing (Gironniera nervosa Planch CANNABACEA) behavior (N = 5 cases) and parasite (Streptopharagus pigmentatus) expulsion (N = 4 cases), recorded during 4,300 hr of direct animal observations during two distinct research projects. We recovered 4–18 rough, hairy, and hispid surfaced leaves from each sample, undigested and folded, from the freshly evacuated feces of five different individuals (2 males, 3 females, 5 to 34+ years old) living in three different social groups, between the hours of 06:00 to 10:30. Based on close inspection of the leaves, as observed in chimpanzees, it was clear that they were taken into the mouth, one at a time, folded and detached from the stem with the teeth before swallowing them whole. All instances occurred during the rainy season, the time when nematode worms were also found in the feces, although they were not found together with leaves in the same feces. These striking similarities in the details of leaf swallowing between white‐handed gibbons and African great apes, and other animal species, suggest a similar self‐medicative function. Am. J. Primatol. 9999:XX–XX, 2016. © 2016 Wiley Periodicals, Inc.

Source: American Journal of Primatology - October 25, 2016 Category: Psychiatry & Psychology Authors: Claudia Barelli, Michael A. Huffman Tags: Research Article Source Type: research