Title
Bigger groups have fewer parasites and similar cortisol levels: A multi-group analysis in red colobus monkeys
Author(s)
Snaith T.V., Chapman C.A., Rothman J.M., Wasserman M.D.
Published
2008
Publisher
American Journal of Primatology
Abstract
If stress and disease impose fitness costs, and if those costs vary as a function of group size, then stress and disease should exert selection pressures on group size. We assessed the relationships between group size, stress, and parasite infections across nine groups of red colobus monkeys (Procolobus rufomitratus) in Kibale National Park, Uganda. We used fecal cortisol as a measure of physiological stress and examined fecal samples to assess the prevalence and intensity of gastrointestinal helminth infections. We also examined the effect of behaviors that could potentially reduce parasite transmission (e.g., increasing group spread and reducing social interactions). We found that cortisol was not significantly related to group size, but parasite prevalence was negatively related to group size and group spread. The observed increase in group spread could have reduced the rate of parasite transmission in larger groups; however, it is not clear whether this was a density-dependent behavioral counter-strategy to infection or a response to food competition that also reduced parasite transmission. The results do not support the suggestion that gastrointestinal parasitism or stress directly imposed group-size-related fitness costs, and we cannot conclude that they are among the mechanisms limiting group size in red colobus monkeys. © 2008 Wiley-Liss, Inc.
Keywords
behavioral ecology; disease; disease transmission; group behavior; group size; host-parasite interaction; parasite; parasite transmission; primate; stress; Africa; East Africa; Kibaale; Sub-Saharan Africa; Uganda; Western Province [Uganda]; Colobinae; Colobus; Colobus sp.; Procolobus badius; Procolobus rufomitratus; Vermes; hydrocortisone; animal; article; chemistry; Colobinae; feces; female; male; metabolism; parasitology; population density; psychological aspect; social behavior; stress; Animals; Colobus; Feces; Female; Hydrocortisone; Male; Population Density; Social Behavior; Stress
Access Full Text
A full-text copy of this article may be available. Please email the WCS Library to request.
![]()
Back
PUB10510