Abstract

Sex-biased dispersal is often explained by assuming that the resource-defending sex pays greater costs of moving from a familiar area. We hypothesize that sex-biased dispersal may also be caused by a sex bias in breeding site availability. In avian resource-defense mating systems, site availability is often more constrained for females: males can choose from all vacant sites, whereas females are restricted to sites defended by males. Using data on breeding dispersal of a migratory passerine, we show that average number of available breeding options and availability of the previous year's territory was greater for males than females. The female bias in site unavailability may explain the female bias in probability of breeding dispersal because there was no sex bias in dispersal among birds with their previous year's territory available. We suggest that sex biases in the availability of breeding options may be an important factor contributing to observed variation in sex-biased dispersal patterns

Keywords

arrival time; breeding dispersal; habitat selection; mating

Published in

American Naturalist
2008, Volume: 171, number: 6, pages: 844-850
Publisher: UNIV CHICAGO PRESS

SLU Authors

• Arlt, Debora

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Pärt, Tomas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1086/587521

Permanent link to this page (URI)

https://res.slu.se/id/publ/15573