Oecologia

, Volume 170, Issue 4, pp 979–986

Philopatric predisposition to predation-induced ecological traps: habitat-dependent mortality of breeding eiders

Authors

    • ARONIA Coastal Zone Research TeamÅbo Akademi University and Novia University of Applied Sciences
    • Centre for Environmental and Climate ResearchLund University
  • Markus Öst
    • ARONIA Coastal Zone Research TeamÅbo Akademi University and Novia University of Applied Sciences
  • Patrik Karell
    • Department of Biology, Section for Evolutionary Ecology, Ecology BuildingLund University
    • Department of Biosciences, Environmental and Marine Biology, Behavioural and Evolutionary Ecology GroupÅbo Akademi University
  • Kim Jaatinen
    • ARONIA Coastal Zone Research TeamÅbo Akademi University and Novia University of Applied Sciences
  • Mikael Kilpi
    • ARONIA Centre for Environmental ResearchÅbo Akademi University and Novia University of Applied Sciences
Population ecology - Original research

DOI: 10.1007/s00442-012-2378-9

Cite this article as:
Ekroos, J., Öst, M., Karell, P. et al. Oecologia (2012) 170: 979. doi:10.1007/s00442-012-2378-9

Abstract

Because population size is sensitive to changes in adult survival, adult survival may be buffered against environmental variability. Philopatry may be adaptive in changing environments, but it could also constrain breeding habitat selection under changing conditions such as shifting predation regimes. Habitat preference and quality could become decoupled in long-lived philopatric species that evolved in stable environments when suddenly faced by increased adult predation risk, as dispersal may be triggered by past reproductive failure. We evaluated whether the Baltic eider (Somateria m. mollissima) population may currently face a predation-induced ecological trap. Eiders are philopatric and nest on open and forested islands. We hypothesized that open-nesting females would be disproportionately affected by increased predation. We compared female annual survival in these two habitats in 1996–2010. We also tested for effects of time trends, winter severity (NAO), female body condition, and habitat-specific predation pressure on survival. Our results revealed the lowest survival recorded for this species (Φ = 0.720), and survival on open islands was significantly lower (Φ = 0.679) than on forested islands (Φ = 0.761). Nonetheless, only 0.7 % of females changed breeding habitat type despite ample availability of alternative islands, and breeding phenology in both habitats was similar. Female survival increased with body condition, while it was unrelated to winter climate and stable over time. Open islands had a higher predation pressure on incubating females. Breeding philopatry results in a predator-mediated ecological trap for open-nesting eiders. Our results contribute to explaining the drastic decline of the Baltic eider population.

Keywords

Body conditionHabitat selectionPredation riskSite fidelitySurvival analysis

Copyright information

© Springer-Verlag 2012