Abstract # 201:

Scheduled for Monday, September 21, 2009 11:45 AM-11:55 AM: Session 20 (Del Mar Room) Oral Presentation


ENVIRONMENTAL AND SPATIAL INFLUENCES ON URINE-WASHING BEHAVIOR IN WHITE-FACED CAPUCHINS AT SANTA ROSA NATIONAL PARK, COSTA RICA

F. A. Campos and L. M. Fedigan
University of Calgary, Dept. of Anthropology, 2500 University Dr. NW, Calgary, AB T2N1N4, Canada
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Urine-washing (UW) is a peculiar behavior, common among Cebids, that involves applying urine to the hands and feet. While its appearance suggests a scent-marking behavior, empirical evidence for its functional significance remains highly contradictory. I used 395h of focal animal samples to examine environmental and spatial influences on UW behavior in wild white-faced capuchins (Cebus capucinus) inhabiting a highly seasonal dry forest in Costa Rica. UW frequency per pooled focal hour was over 10 times greater in the dry season, and bootstrapping analysis revealed that the low relative humidity rather than the heat of the dry season may have been primarily responsible for the seasonal difference. Some individuals [3/13] urine-washed in significant association with foraging on ant-defended acacia trees [behavioral co-occurrence above 95% bootstrap confidence interval], but most urine-washes did not occur during foraging. The behavior states immediately before and after UW differed significantly from expectations based on baseline activity rates: UW was relatively more frequent in travel, vigilance, and self-grooming contexts and less frequent in resting, foraging, and social contexts [Friedman’s tests, p<0.001 for 6 behavior contexts]. The hypothesis that UW is used for between-group signaling was not strongly supported. Although UW was more frequent in spatially peripheral areas and less frequent in heavily used areas, UW was not significantly more common in areas where intergroup encounters occurred or near valuable resources.