Behavioral Ecology and Sociobiology

, Volume 56, Issue 1, pp 81–88

Brood neglect and contingent foraging behavior in a pelagic seabird

  • Sue Lewis
  • Keith C. Hamer
  • Luisa Money
  • Richard Griffiths
  • Sarah Wanless
  • Thomas N. Sherratt
Original Article
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Abstract

Among species where there is a risk to leaving offspring unattended, parents usually take alternating shifts guarding their young. However, they may occasionally exhibit brood neglect by leaving their offspring unattended at the nest. To investigate this phenomenon further, we examined the foraging behavior of the northern gannet (Morus bassanus) during chick-rearing. This species has a prolonged nestling period (13 weeks) and the single chick is usually guarded by one or other of its parents, because unattended chicks are frequently attacked by conspecifics. We tested the prediction that the foraging behavior of adults when they left their offspring alone at the nest (unattended trips) would differ in character to when adults left offspring with their partner (attended trips). Brood neglect typically occurred after a longer-than-average attendance period at the nest. Unattended trips were, on average, about half the duration of attended trips, and therefore much closer to the colony. There was also a difference in departure direction between attended and unattended trips, with unattended trips tending to be northeast of the colony. Chicks were fed by parents after both attended and unattended trips, but the frequency and the duration of unattended trips increased as chicks grew older whereas the duration of attended trips decreased as chicks grew. These results indicate that parents may be making a trade-off between risk of attack to their offspring and food-intake rate, and that the solution to this trade-off is dependent on chick age.

Keywords

Dual foraging strategy Gannet Morus bassanus Nest attendance State-dependent foraging 

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Sue Lewis
    • 1
  • Keith C. Hamer
    • 2
    • 3
  • Luisa Money
    • 1
  • Richard Griffiths
    • 4
  • Sarah Wanless
    • 1
  • Thomas N. Sherratt
    • 2
    • 5
  1. 1.NERC Centre for Hydrology and EcologyBanchory Research StationBanchoryUK
  2. 2.School of Biological and Biomedical SciencesUniversity of DurhamDurhamUK
  3. 3.Ecology and Evolution Group, School of BiologyUniversity of LeedsLeedsUK
  4. 4.Ornithology Group, Division of Environmental and Evolutionary BiologyUniversity of GlasgowGlasgow UK
  5. 5.Department of BiologyCarleton UniversityOttawaCanada

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