Publication Date:
2010-06-10
Description:
An optimal search theory, the so-called Levy-flight foraging hypothesis, predicts that predators should adopt search strategies known as Levy flights where prey is sparse and distributed unpredictably, but that Brownian movement is sufficiently efficient for locating abundant prey. Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Levy behaviour has recently been questioned. Consequently, whether foragers exhibit Levy flights in the wild remains unclear. Crucially, moreover, it has not been tested whether observed movement patterns across natural landscapes having different expected resource distributions conform to the theory's central predictions. Here we use maximum-likelihood methods to test for Levy patterns in relation to environmental gradients in the largest animal movement data set assembled for this purpose. Strong support was found for Levy search patterns across 14 species of open-ocean predatory fish (sharks, tuna, billfish and ocean sunfish), with some individuals switching between Levy and Brownian movement as they traversed different habitat types. We tested the spatial occurrence of these two principal patterns and found Levy behaviour to be associated with less productive waters (sparser prey) and Brownian movements to be associated with productive shelf or convergence-front habitats (abundant prey). These results are consistent with the Levy-flight foraging hypothesis, supporting the contention that organism search strategies naturally evolved in such a way that they exploit optimal Levy patterns.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Humphries, Nicolas E -- Queiroz, Nuno -- Dyer, Jennifer R M -- Pade, Nicolas G -- Musyl, Michael K -- Schaefer, Kurt M -- Fuller, Daniel W -- Brunnschweiler, Juerg M -- Doyle, Thomas K -- Houghton, Jonathan D R -- Hays, Graeme C -- Jones, Catherine S -- Noble, Leslie R -- Wearmouth, Victoria J -- Southall, Emily J -- Sims, David W -- England -- Nature. 2010 Jun 24;465(7301):1066-9. doi: 10.1038/nature09116. Epub 2010 Jun 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20531470" target="_blank"〉PubMed〈/a〉
Keywords:
Animal Identification Systems
;
Animals
;
Biological Evolution
;
*Ecosystem
;
Exploratory Behavior/physiology
;
Fishes/*physiology
;
*Food
;
Likelihood Functions
;
Locomotion/*physiology
;
Marine Biology
;
*Models, Biological
;
Perciformes/physiology
;
Predatory Behavior/*physiology
;
*Seawater
;
Sharks/physiology
;
Swimming/physiology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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