Environmental context explains Lévy and Brownian movement patterns of marine predators

Humphries, NE; Queiroz, N; Dyer, JRM; Pade, NG; Musyl, MK; Schaefer, KM; Fuller, DW; Brunnschweiler, JM; Doyle, TK; Houghton, JDR; Hays, GC; Jones, CS; Noble, LR; Wearmouth, VJ; Southall, EJ; Sims, DW. 2010 Environmental context explains Lévy and Brownian movement patterns of marine predators. Nature, 465 (7301). 1066-1069. 10.1038/nature09116

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Official URL: http://dx.doi.org/10.1038/nature09116

Abstract/Summary

An optimal search theory, the so-called Levy-flight foraging hypothesis(1), 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(2-4). Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Levy behaviour has recently been questioned(5,6). 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(1,7), supporting the contention(8,9) that organism search strategies naturally evolved in such a way that they exploit optimal Levy patterns.

Item Type: Publication - Article
Additional Keywords: Zoology Environmental science Animal behaviour Applied physics Engineering
Subjects: Biology
Ecology and Environment
Marine Sciences
Zoology
Divisions: Marine Biological Association of the UK > Ecosystems and Environmental Change > Movement ecology, behaviour and population structure
Depositing User: Nick Humphries
Date made live: 25 Sep 2014 10:45
Last Modified: 06 Jun 2017 16:12
URI: http://plymsea.ac.uk/id/eprint/6189

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