Evidence of intra-specific competition for food in a pelagic seabird

Sue Lewis, T. N. Sherratt, K. C. Hamer, S. Wanless

    Research output: Contribution to journalArticle

    268 Citations (Scopus)

    Abstract

    The factors affecting the population dynamics of seabirds have long intrigued biologists(1-5). Current data suggest that density-dependent depletion of prey during the breeding season may regulate population size(6-9). However, much of the evidence for this has been circumstantial, and the underlying mechanisms are unclear(5,10). Here, we show that the per capita population growth rates of northern gannet Morus bassanus at colonies in Britain and Ireland have declined with increasing population size. Furthermore, direct observations reveal that the mean foraging trip duration of breeding gannets is positively correlated with colony size, both among colonies of different sizes in the same year, and within colonies as they change in size. To understand this phenomenon, we have developed a model which demonstrates that disturbance of fish alone can readily generate conditions under which gannets at larger colonies have to travel further to obtain food.

    Original languageEnglish
    Pages (from-to)816-819
    Number of pages3
    JournalNature
    Volume412
    DOIs
    Publication statusPublished - 2001

    Keywords

    • COLONY DISTRIBUTIONS
    • BRITISH-ISLES
    • POPULATION
    • SIZE
    • SEA

    Cite this

    Lewis, S., Sherratt, T. N., Hamer, K. C., & Wanless, S. (2001). Evidence of intra-specific competition for food in a pelagic seabird. Nature, 412, 816-819. https://doi.org/10.1038/35090566