Affiliation:
1. Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
2. Department of Medical Genetics, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, AB T2N 4N1, Canada
Abstract
Abstract
The polymorphic color vision system present in most North, Central, and South American monkeys is a textbook case of balancing selection, yet the mechanism behind it remains poorly understood. Previous work has established task-specific foraging advantages to different color vision phenotypes: dichromats (red-green colorblind) are more efficient foraging for invertebrates, while trichromats (color “normal” relative to humans) are more efficient foraging for “reddish” ripe fruit, suggesting that niche differentiation may underlie the maintenance of color vision variation. We explore a prediction of the niche differentiation hypothesis by asking whether dichromatic and trichromatic capuchin monkeys (Cebus imitator) diverge in their foraging activity budget, specifically testing whether dichromats forage more frequently for invertebrates and trichromats forage more frequently for “reddish” ripe fruit. To assess this, we analyze a large data set of behavioral scan samples (n = 21 984) from 48 wild adult female capuchins of known color vision genotype, dominance rank, and reproductive status, together with models of food conspicuity. We find no significant differences between dichromats and trichromats in the frequency of scans spent foraging for different food types but do find that nursing females forage less overall than cycling females. Our results suggest that the potential for color-vision-based niche differentiation in foraging time may be curtailed by the energetic requirements of reproduction, behavioral synchrony caused by group living, and/or individual preferences. While niche differentiation in activity budgets by color vision type is not apparent, fine-scale niche differentiation may be occurring. This research enhances our understanding of the evolutionary processes maintaining sensory polymorphisms.
Funder
Wenner-Gren Foundation
Leakey Foundation
Natural Sciences and Engineering Research Council of Canada
Canada Research Chairs
American Society of Primatologists
Alberta Children's Hospital Research Institute
Publisher
Oxford University Press (OUP)
Subject
Animal Science and Zoology,Ecology, Evolution, Behavior and Systematics
Cited by
6 articles.
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