Habitat-mediated population limitation in a colonial central-place forager: the sky is not the limit for the black-browed albatross

Wakefield, E. D. , Phillips, R. A. and Matthiopoulos, J. (2014) Habitat-mediated population limitation in a colonial central-place forager: the sky is not the limit for the black-browed albatross. Proceedings of the Royal Society of London Series B: Biological Sciences, 281(1778), p. 20132883. (doi: 10.1098/rspb.2013.2883) (PMID:24430849) (PMCID:PMC3906941)

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Abstract

Animal populations are frequently limited by the availability of food or of habitat. In central-place foragers, the cost of accessing these resources is distance-dependent rather than uniform in space. However, in seabirds, a widely studied exemplar of this paradigm, empirical population models have hitherto ignored this cost. In part, this is because non-independence among colonies makes it difficult to define population units. Here, we model the effects of both resource availability and accessibility on populations of a wide-ranging, pelagic seabird, the black-browed albatross Thalassarche melanophris. Adopting a multi-scale approach, we define regional populations objectively as spatial clusters of colonies. We consider two readily quantifiable proxies of resource availability: the extent of neritic waters (the preferred foraging habitat) and net primary production (NPP). We show that the size of regional albatross populations has a strong dependence, after weighting for accessibility, on habitat availability and to a lesser extent, NPP. Our results provide indirect support for the hypothesis that seabird populations are regulated from the bottom-up by food availability during the breeding season, and also suggest that the spatio-temporal predictability of food may be limiting. Moreover, we demonstrate a straightforward, widely applicable method for estimating resource limitation in populations of central-place foragers.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Wakefield, Dr Ewan and Matthiopoulos, Professor Jason
Authors: Wakefield, E. D., Phillips, R. A., and Matthiopoulos, J.
College/School:College of Medical Veterinary and Life Sciences > Institute of Biodiversity Animal Health and Comparative Medicine
Journal Name:Proceedings of the Royal Society of London Series B: Biological Sciences
Publisher:The Royal Society
ISSN:0962-8452
ISSN (Online):1471-2954
Copyright Holders:Copyright © 2014 The Authors
First Published:First published in Proceedings of the Royal Society of London Series B: Biological Sciences 281(1778):20132883
Publisher Policy:Reproduced under a Creative Commons License

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