Intentional ingestion of wax scales (Ceroplastes sp.) in a group of Alouatta caraya in the Argentinean Wet Chaco

PEREZ-RUEDA, AMPARO; CANTARELLI, VERONICA; RAÑO, MARIANA; KOWALEWSKI, M MARTIN

Recife

Congreso; II Congresso Latino Americano XV Congresso Brasileiro de Primatologia; 2013

Sociedad Brasileira de Primatologia-Sociedad Latinoamericana de Primatologia

Alouatta caraya like all other howlers are folivorous-frugivorous primates. Howler monkeys are highly selective feeders and rely on slow and efficient digestion to extract energy and nutrients locked up in leaf structural carbohydrates. A strategy of energy minimization, moving little and resting for long periods of time each day, allow them to subsist predominantly on a diet of hard to digest leaves. However, several field studies report that arthropods may be inadvertently ingested with the vegetable matter and there are also observations of intentional consumption of bird eggs during periods of food scarcity. Here we report intentional consumption of wax scales, Ceroplastes sp. We observed 2 free-ranging social groups of Alouatta caraya living in the protected area of Chaco National Park, in Northern Argentina (26° 40´S, 59° 48´O). Groups were overlapped, and had no variation in the availability of any food item. We recorded behavior via focal animal-sampling to estimate activity pattern and diet composition form February to March 2012. We only observed wax scale feeding in one group, although the scales were available for both groups. All group members (n=5) consumed scales. Their feeding time represented 19.91% of their activity budget, and they devoted 53% of this time to feed on leaves, 38% to fruits, 7% to scales, and 2% to others. We presumed this was a case of novelty behavior for this group. The digestibility of animal protein is higher than that of plant protein. Scales also produce large amounts of honeydew, and this could represent an extra source of carbohydrates that attract howlers to feed on them. Dietary flexibility of black and gold howler monkeys is higher than we thought and we might underestimate animal matter ingestion. Feeding behavior is often difficult to observe, especially for arboreal primates, and insect ingestion can be easily overlooked.