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Predation risk as a driving force for sexual segregation: A cross-population comparison


Yan Wong


John R. G. Dyer

Darren P. Croft


Darren P. Croft

Amy S. Wade

Chantima Piyapong



Christos C. Ioannou

John R. G. Dyer

Ben B. Chapman


Yan Wong

Jens Krause


Sexual segregation is widespread throughout the animal kingdom. Although a number of hypotheses have been proposed to account for observed patterns, the generality of the mechanisms remains debated. One possible reason for this is the focus on segregation patterns in large mammals such as ungulates, where the majority of studies are descriptions of a single population. Here, we present the results of a cross-population comparison of patterns of sexual segregation in the Trinidadian guppy, Poecilia reticulata. We relate observed patterns to experimental quantification of predation risk and sexual harassment of females by males in eight populations. We find that the degree of segregation increases with predation risk, with deeper waters becoming increasingly female biased. Furthermore, we observed that levels of male harassment are lower in deeper water but only in those rivers that contain major guppy predators. We conclude that sexual segregation in guppies is consistent with the predation risk hypothesis: sexual segregation results from a combination of predation risk driving males ( the more vulnerable sex) into less risky habitats and females gaining benefits of reduced sexual harassment by remaining in high-predation environments.


Croft, D., Morrell, L. J., Wade, A. S., Piyapong, C., Ioannou, C. C., Dyer, J. R. G., …Krause, J. (2006). Predation risk as a driving force for sexual segregation: A cross-population comparison. The American naturalist, 167(6), 867-878.

Journal Article Type Article
Acceptance Date Mar 14, 2006
Online Publication Date Apr 28, 2006
Publication Date Jun 30, 2006
Print ISSN 0003-0147
Electronic ISSN 1537-5323
Publisher University of Chicago Press
Peer Reviewed Peer Reviewed
Volume 167
Issue 6
Pages 867-878
Keywords Sexual segregation; Predation risk; Habitat segregation; Sexual harassment; Guppy; Poecilia reticulata
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