Abstract # 104:

Scheduled for Tuesday, June 4, 2002 09:00 AM-09:15 AM: Session 12 (Room 16/17, Cox Convention Center) Oral Presentation


DICHROMATIC AND TRICHROMATIC MARMOSETS (Callithrix geoffroyi) DIFFER IN RELATIVE FORAGING ABILITY FOR RED-GREEN COLOR-CAMOUFLAGED AND NON-CAMOUFLAGED FOOD.

N. G. Caine1, A. K. Surridge2 and N. I. Mundy2
1Cal State San Marcos, Dept. of Psychology, California State University, San Marcos, CA 92096, USA, 2Institute of Biological Anthropology, University of Oxford, UK
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      The importance of trichromatic color vision in primates is shown by its maintenance in many lineages, but less attention has been paid to the possibility that dichromats may have advantages over trichromats in certain situations. The foraging ability of trichromatic and dichromatic Geoffroy’s marmosets (Callithrix geoffroyi) for colored cereal balls (Kix®) was tested under conditions of red-green color camouflage (orange/green Kix® against an orange/green background) or lack of camouflage (Kix® same color as background) in a naturalized captive setting at the Center for Reproduction of Endangered Species, San Diego Wild Animal Park. In separate experiments designed to test foraging ability at long distances (up to 6m) and short distances (less than 0.5m), Wilcoxon tests revealed that trichromats found significantly fewer Kix® under the camouflage condition than the non-camouflage condition. In contrast, no differences were found in the ability of dichromats to detect color-camouflaged versus non-camouflaged Kix®. No significant differences were found between dichromats and trichromats (Mann-Whitney U tests) for either camouflaged or non-camouflaged Kix®, but these comparisons were confounded by high inter-individual variability. These results demonstrate a potential foraging cost to trichromats which is absent in dichromats.