Abstract # 4574 Poster # 156:

Scheduled for Friday, June 21, 2013 07:00 PM-09:00 PM: Session 21 (SG Foyer ABC) Poster Presentation


PERCEIVED PREDATOR ENCOUNTERS DO NOT INFLUENCE THE RANGING BEHAVIOR OF SPIDER MONKEYS IN YASUNI, ECUADOR

S. A. Suarez, E. L. Stefani and A. B. Blackburn
Anthropology Department, Miami University, 120 Upham Hall, Oxford, OH 45056, USA
line
     Wild primates are attracted to feeding sites, but may avoid parts of their home range where they recently encountered predators. Spider monkey fission-fusion social organization is characterized by subgroups containing few animals, theoretically resulting in high predation pressure, most likely from jaguars, eagles, and tayra. Therefore, we ask whether wild spider monkeys (Ateles belzebuth) avoid locations where they have given anti-predation vocalizations. Anti-predator vocalizations (n=60) were collected ad libitum during ten two-week focal samples of habituated focal spider monkey females conducted from 1999-2000 in Yasuni, Ecuador. In nearly all cases, we did not see predators. We mapped the location of focal subjects at 5-minute intervals all day during the observation period. We analyzed ranging patterns of monkeys using ArcMap 10.1, noting how many days until monkeys returned to a call location. We compared return intervals to randomly selected location data points (control, n=67) from the same observation period. Observed monkeys were no less likely to return to the location of an anti-predator call than to control locations (t-ratio=0.6, DF=6, P=0.5370). Spider monkeys returned to the site of the vocalization within one day of the call in 40% of the cases, and within two days in over 50% of cases. While predation pressure is likely to be important for spider monkeys, anti-predator vocalizations did not deter Yasuni spider monkeys from these areas of their home range.