Foraging success of biological Levy flights recorded in situ.

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Humphries, Nicolas E, Weimerskirch, Henri, Queiroz, Nuno, Southall, Emily J, Sims, David W
• Other Authors: The Laboratory (Marine Biological Association of the United Kingdom), Marine Biological Association of the United Kingdom (MBA), School of Marine Science and Engineering, Plymouth University, Centre d'études biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Universidade do Porto, National Oceanography Centre Southampton (NOC), University of Southampton, Centre for Biological Sciences (University of Southampton)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: [SDE]Environmental Sciences; Levy; Diomedea exulans
• Online Access: https://hal.archives-ouvertes.fr/hal-00700869; https://doi.org/10.1073/pnas.1121201109

International audience It is an open question how animals find food in dynamic natural environments where they possess little or no knowledge of where resources are located. Foraging theory predicts that in environments with sparsely distributed target resources, where forager knowledge about resources' locations is incomplete, Lévy flight movements optimize the success of random searches. However, the putative success of Lévy foraging has been demonstrated only in model simulations. Here, we use high-temporal-resolution Global Positioning System (GPS) tracking of wandering (Diomedea exulans) and black-browed albatrosses (Thalassarche melanophrys) with simultaneous recording of prey captures, to show that both species exhibit Lévy and Brownian movement patterns. We find that total prey masses captured by wandering albatrosses during Lévy movements exceed daily energy requirements by nearly fourfold, and approached yields by Brownian movements in other habitats. These results, together with our reanalysis of previously published albatross data, overturn the notion that albatrosses do not exhibit Lévy patterns during foraging, and demonstrate that Lévy flights of predators in dynamic natural environments present a beneficial alternative strategy to simple, spatially intensive behaviors. Our findings add support to the possibility that biological Lévy flight may have naturally evolved as a search strategy in response to sparse resources and scant information.