Abstract # 63:

Scheduled for Thursday, August 18, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation


SEED DISPERSAL PATTERNS OF WHITE-FACED CAPUCHINS (Cebus capucinus) AND MANTLED HOWLER MONKEYS (Alouatta palliata), LA SUERTE BIOLOGICAL STATION, COSTA RICA

S. J. Smith
University of Illinois, Urbana-Champaign, Department of Anthropology, 109 Davenport Hall, 607 S. Mathews , Urbana, IL 61801, USA
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     Many primate species are believed to play an important role in seed dispersal, however it is unlikely that all primates treat and disperse seeds in the same manner. This study examines differences in the volumes, quantities, and diversity of seeds dispersed by capuchins and howlers in Costa Rica. Fecal samples from capuchins (n = 72) and howlers (n = 155) were collected during behavioral follows from Sept. – Nov. 2002 (howlers), May – July 2003 (both species), and June - July 2004 (capuchins). Seeds obtained from defecations were counted, measured, identified, and germinated in petri dishes to test for viability. Ninety-six percent of capuchin defecations and 48% of howler defecations contained undamaged seeds. Seed-containing howler defecations contained larger quantities (U = 1428.0, P < 0.01) and volumes (U = 2039.5, P = 0.03) of seeds than those of capuchins, however considerable intraspecific variation was observed in volumes of seeds dispersed for both howlers (> 0.01 – 15.48 ml, mean = 1.35 ml) and capuchins (0.01 – 4.91 ml, mean = 0.86 ml). The large variation in volumes of seeds in defecations of both species and the considerable overlap in their ranges suggest that the defecation patterns of these two species may not result in consistent or predictable consequences for the fate of the seeds they disperse. Supported by a National Science Foundation Graduate Research Fellowship.