Behavioral Ecology Advance Access published online on November 5, 2009
Behavioral Ecology, doi:10.1093/beheco/arp146
Predator escape tactics in birds: linking ecology and aerodynamics
a Department of Marine Ecology, Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands b Groupe de Recherche en Écologie Comportementale et Animale, Département des sciences biologiques, Université du Québec à Montréal, Case postale 8888, Succursale Centre-ville, Montréal, Québec, H3C 3P8, Canada c Department of Physical Oceanography, Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands d Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
Address correspondence to P.J. van den Hout. E-mail: piet.van.den.hout{at}nioz.nl.
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Abstract |
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In most birds, flight is the most important means of escape from predators. Impaired flight abilities due to increased wing loading may increase vulnerability to predation. To compensate for an increase in wing loading, birds are able to independently decrease body mass (BM) or increase pectoral muscle mass (PMM). Comparing nearshore and farshore foraging shorebird species, we develop a theory as to which of these responses should be the most appropriate. We hypothesize that nearshore foragers should respond to increased predation by increasing their PMM in order to promote speed-based escape. Instead, farshore foragers should decrease BM in order to improve agility for maneuvering escape. Experiments on 2 shorebird species are consistent with these predictions, but on the basis of the theoretical framework for evaluating effect size and biological significance developed here, more experiments are clearly needed.
Key words: aerodynamics, body mass, escape performance, flight, pectoral muscle, phenotypic flexibility, raptors, risk management.
Received 7 April 2009; revised 10 September 2009; accepted 23 September 2009.