1Anthropology, Hunter College of the City University of New York, 2Institute of Natural Sciences, Massey University, 3Anthropology & School of Environment, McGill University, 4New York Consortium in Evolutionary Primatology
Friday All day, Plaza Level
Redtail monkeys (Cercopithecus ascanius) are traditionally considered frugivorous, but invertebrates can compose a large part of their diets in some areas. We examined the nutritional contributions of insects in the diets of redtail monkeys in Kibale National Park, Uganda by conducting full day focal follows of adult females in one group from August 2010 to August 2011. Female redtails spent 63% of their foraging time eating insects (including solitary insects and leaf galls), 22% on reproductive parts of plants (including ripe fruit, unripe fruit, flowers, seeds), and 15% on leaves (including young leaves, mature leaves, leaf petioles, leaf buds). Redtails fed primarily on solitary insects, such as cicadas and crickets, as opposed to social invertebrates. Of the consumed insects that could be identified, 81.6% were cicadas (Order Hemiptera), 4.3% were grasshoppers (Order Orthoptera), 0.5% were crickets (Order Orthoptera), 13.5% caterpillars (Order Lepidoptera). Insects were fairly low in fat (<10%), very high in crude protein content (mean = 69%, range = 39 – 78%), and contained moderate amounts of chitin (ADF mean = 16%, range = 8 – 36%). Insects, rather than fruits and leaves contributed the majority of protein and energy in the redtail diet; over 50% of protein and over 50% of energy were obtained through insectivory according to weight-based estimates of food intake. Our findings demonstrate high insectivory in the diet of a species traditionally categorized as a frugivore and indicate that the nutritional importance of invertebrates in the diets of some primates has been underestimated.
This research was funded by Hunter College and the National Science Foundation Grant #0922709