Sex-specific fitness consequences of dispersal in Siberian jays
In most birds, natal dispersal is female-biased, but the selective pressures leading to this pattern have rarely been explored with comprehensive data on lifetime reproductive success. In territorial birds, the benefit of philopatry should be higher for males than for females when males establish territories for which knowledge about the local environment is important. As females may use male characteristics for mate choice, and hence indirectly for territory choice, the benefit from the direct knowledge of the local environment may be lower for females than males. We tested this hypothesis using data from a long-term study of group living corvids, the Siberian jays (Perisoreus infaustus). In this species, the socially dominant offspring delay dispersal while the sub-dominant offspring leave the family group directly after reaching independence. Our results show that natal dispersal distance (a proxy for local knowledge) was related to sex and dispersal timing (a proxy for “quality”): Females and early dispersers traveled further on average than males and delayed dispersers. Furthermore, dispersal distance and timing were negatively related to the number of recruits produced over an individual’s lifetime in males, but not in females. Hence, the results support the hypothesis that the female-biased natal dispersal found in this and other bird species may come about through higher lifetime reproductive success of philopatric males than females.
KeywordsNatal dispersal Philopatry Fitness Lifetime reproductive success Siberian jay Local knowledge
This work was financially supported by the Academy of Finland (to P.G. and to J.M.), the University of Helsinki (to J.M.), Maj & Tor Nessling Foundation (to J.M.), and Kone Foundation (to P.G.). Bo-Göran Lillandt managed the fieldwork for many years and put the data at our disposal. He and many others also collected the data. Hanna Kokko, John Loehr, Amber Teacher, and Mark Hauber made helpful comments on the manuscript.
Fieldwork for this study has been carried out under the necessary licenses and was in accordance with the relevant animal welfare regulations. The authors declare that they have no conflict of interest.
- Andersson M (1994) Sexual selection. Princeton University Press, PrincetonGoogle Scholar
- Bélichon S, Clobert J, Massot M (1996) Are there differences in fitness components between philopatric and dispersing individuals? Acta Oecol 17:503–517Google Scholar
- Blomgren A (1964) Lavskrika. Bonniers, StockholmGoogle Scholar
- Clobert J, Danchin E, Dhondt AA, Nichols JD (2001) Dispersal. Oxford University Press, OxfordGoogle Scholar
- Cox DR (1972) Regression models and life tables. Biometrics 39:67–77Google Scholar
- Cramp S, Perrins CM (eds) (1993) The birds of the western Palaearctic. Vol. VII. Oxford University Press, OxfordGoogle Scholar
- Hanski I, Gilpin ME (1997) Metapopulation biology: ecology, genetics and evolution. Academic, LondonGoogle Scholar
- Lillandt B (1993) Lavskrikans (Perisoreus infaustus) populationsutveckling inom ett sammanhängande skogsområde i Sydösterbotten 1974–1992. M.Sc. Thesis, University of HelsinkiGoogle Scholar
- Lillandt B, Bensch S, von Schantz T (2001) Parentage determination in kin-structured populations: microsatellite analyses in the Siberian Jay Perisoreus infaustus during a 25-year population study. Avian Sci 1:3–14Google Scholar
- R Development Core Team (2007) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar