Title: | The evolution of prey body size reaction norms in diverse communities |
Address: | "School of Forestry and Environmental Studies, Yale University, 370 Prospect Street, New Haven, CT 06511 USA. urban@nceas.ucsb.edu" |
DOI: | 10.1111/j.1365-2656.2007.01337.x |
ISSN/ISBN: | 1365-2656 (Electronic) 0021-8790 (Linking) |
Abstract: | "1. Heterogeneous predation risks can select for predator-specific plastic defences in prey populations. However, diverse predation threats can generate diffuse selection, which, in turn, can lead to the evolution of more generalized reaction norms. Unreliable predator cues also can select for more generalized plasticity in prey. 2. Here, I evaluated the extent to which variation in risk from a focal predator vs. variation in risk from predator diversity and composition were associated with variation in body mass reaction norms in 18 prey populations. Toward this end, I assayed the body mass reaction norms in a common garden experiment for spotted salamander larvae Ambystoma maculatum in response to marbled salamander predators Ambystoma opacum, local predator richness and the densities of two auxiliary predator species. 3. When raised under controlled conditions, prey larvae generally were smaller when exposed to A. opacum kairomones. Among populations, the mean and slope of body mass variation was unrelated to A. opacum's local density. 4. Predator richness and several key environmental factors were not associated with reaction norm variation. Instead, the density of an auxiliary newt predator species was correlated with reduced mass reaction norm slopes. Results suggest that diffuse selection from auxiliary predators can modify the evolution of life-history plasticity" |
Keywords: | "Animals Behavior, Animal/physiology *Biodiversity Body Size/*physiology Female Larva Male Phenotype Population Density Population Dynamics Predatory Behavior/*physiology Species Specificity Urodela/*physiology;" |
Notes: | "MedlineUrban, Mark C eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. England 2007/12/18 J Anim Ecol. 2008 Mar; 77(2):346-55. doi: 10.1111/j.1365-2656.2007.01337.x. Epub 2007 Dec 11" |