The 85th Annual Meeting of the American Association of Physical Anthropologists (2016)

Life in a new world: The Silver River rhesus macaques’ feeding ecology and encounters with humans


Anthropology, San Diego State University

April 15, 2016 11:45, A 706/707 Add to calendar

The study of primates living in novel environments represents an interesting context in which to examine patterns of behavioral and ecological flexibility. Our research focused on an understudied, human-introduced primate population living in Florida, U.S.: the Silver River rhesus macaques (Macaca mulatta). We collected data on their feeding ecology and encounters with boaters along the Silver River from January – May 2013 to better understand how this population has ecologically adjusted to life in Florida’s riparian woodlands. Using scan sampling and all-occurrences sampling, we collected 166 hours of diet data and 105 hours of human-macaque encounter data. The Silver River macaques consumed a total of 31 plant species, representing 30% of the plant species in the floodplain swamp. Leaves and other vegetative plant parts (87.5%) were predominantly consumed, with ash trees (Fraxinus spp.) serving as a staple food (66.5% of feeding records). Although human-macaque encounters were frequent (80% of 611 boats observed), only a small proportion of boats (11.5%) provisioned the macaques. Motorized boats (e.g., pontoon and motor boats) were more likely to provision, while kayaks and canoes were more likely to move in close proximity of the macaques. Our results indicate that the Silver River macaques have adjusted to life in Florida by adopting a temperate-dwelling feeding strategy and incorporating locally available foods (e.g., sedges) into their diet. They have also learned that the river’s edge provides opportunities to receive provisions from boaters. However, because the rate of provisioning is low, these foods likely play a filler fallback role.

Supported by National Geographic/Waitt Foundation (grant #W257-12) and San Diego State University.