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Turn costs change the value of animal search paths
Author(s) -
Wilson R. P.,
Griffiths I. W.,
Legg P. A.,
Friswell M. I.,
Bidder O. R.,
Halsey L. G.,
Lambertucci S. A.,
Shepard E. L. C.
Publication year - 2013
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/ele.12149
Subject(s) - offset (computer science) , random walk , computer science , value (mathematics) , tortuosity , energy cost , ecology , mathematical optimization , simulation , economics , mathematics , engineering , biology , environmental economics , statistics , machine learning , geotechnical engineering , porosity , programming language
The tortuosity of the track taken by an animal searching for food profoundly affects search efficiency, which should be optimised to maximise net energy gain. Models examining this generally describe movement as a series of straight steps interspaced by turns, and implicitly assume no turn costs. We used both empirical‐ and modelling‐based approaches to show that the energetic costs for turns in both terrestrial and aerial locomotion are substantial, which calls into question the value of conventional movement models such as correlated random walk or Lévy walk for assessing optimum path types. We show how, because straight‐line travel is energetically most efficient, search strategies should favour constrained turn angles, with uninformed foragers continuing in straight lines unless the potential benefits of turning offset the cost.