Behavioral Ecology and Sociobiology

, Volume 63, Issue 12, pp 1773–1785

Underwater and above-water search patterns of an Arctic seabird: reduced searching at small spatiotemporal scales

  • Kyle Hamish Elliott
  • Roger D. Bull
  • Anthony J. Gaston
  • Gail K. Davoren
Original Paper

Abstract

How predators vary search patterns in response to prey predictability is poorly known. For example, marine invertebrates may be predictable but of low energy value, while fish may be of higher energy value but unpredictable at large (pelagic schools) or small (solitary benthics) spatial scales. We investigated the search patterns of the thick-billed murre (Uria lomvia), an Arctic seabird feeding on invertebrates, pelagic fish, or benthic fish. Foraging ranges at the Coats Island colony are generally smaller (<240 min per trip) than at larger colonies, and many birds specialize in foraging tactics and diet. Underwater search times for benthic fish were higher than for pelagic fish or invertebrates while above-water search times for pelagic fish were higher than for benthic fish or invertebrates. There were few stops during trips. Total trip time, flying time, number of flights, and number of dives were intercorrelated and increased with prey energy content, suggesting that longer trips involved fewer prey encounters due to selection of higher-quality, but rarer, prey items. Flight times were not Lévy-distributed and seabirds may have used area-restricted searches. The high degree of specialization, apparent absence of information center effects, and reduced above-water searching times may be linked to the relatively small colony size and the resulting short commuting distances to feeding areas, leading to greater prey predictability. We concluded that prey predictability over various scales affected predator search patterns.

Keywords

Predator–prey interactions Ecological scale Lévy search pattern Information Center Hypothesis Thick-billed murre Uria lomvia 

Supplementary material

265_2009_801_MOESM1_ESM.mht (530 kb)
ESM Table S1(MHT 529 kb)
265_2009_801_MOESM2_ESM.doc (24 kb)
ESMTime at splashdown (±SE) increases with time at the colony prior to departure.
265_2009_801_MOESM3_ESM.doc (49 kb)
ESMFrequency distribution for (a) arrival and (b) departure times using actual data (columns) and simulations (lines) for thick-billed murres at Coats Island 1999-2007. (DOC 49.0 kb)

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Kyle Hamish Elliott
    • 1
  • Roger D. Bull
    • 2
    • 3
  • Anthony J. Gaston
    • 2
  • Gail K. Davoren
    • 1
  1. 1.Department of ZoologyUniversity of ManitobaWinnipegCanada
  2. 2.Science and Technology BranchEnvironment CanadaOttawaCanada
  3. 3.Canadian Museum of NatureOttawaCanada

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