Evol Ecol Res 1: 251-260 (1999)     Full PDF if your library subscribes.

A comparative study of breeding traits in colonial birds

Guy Beauchamp

Faculty of Veterinary Medicine, University of Montréal, CP 5000, St.-Hyacinthe, Québec J2S 7C6, Canada

e-mail: beauchgu@medvet.umontreal.ca


I examined the effect of an evolutionary transition to coloniality on several breeding traits in birds using 29 pairs of congeners that included one colonial and one solitary breeding species. Males in colonial and solitary species, as well as females, had similar body masses. The extent to which the sexes differed in body mass and plumage characteristics was also similar in colonial and solitary species. Although sexual selection is often assumed to be stronger in colonial species, coloniality appears to be a weak force in the sexual diversification of body mass and plumage characteristics in birds. Colonial species produced heavier eggs and invested more in their offspring per unit of female body mass than their solitary counterpart. The results support the hypothesis that coloniality is associated with greater foraging efficiency, which allows colonial birds to increase parental effort. Although offspring predation risk is often assumed to be smaller in colonial species, a fact that could lead to the production of larger clutches, colonial and solitary species produced clutches of similar size. The results thus provide little support for an effect of differential predation pressure on changes in clutch size in colonial species.

Keywords: birds, clutch size, colonial breeding, egg mass, pairwise comparative method.

IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.


        © 1999 Guy Beauchamp. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.