Risk assessment based on indirect predation cues: revisiting fine‐grained variation

Ecology and Evolution

Michael W. McCoy¹  Stefan K. Wheat²  Karen M. Warkentin³ 

[1] Department of Biology, Virginia Commonwealth University, Richmond, VA;Department of Biology, Whitman College, Walla Walla, WA;Department of Biology, Boston University, Boston, MA

关键词: Inducible defense;    phenotypic plasticity;    predation;    tadpole;   

DOI  :  10.1002/ece3.1552

来源: Wiley

【 摘 要 】

Abstract

To adaptively express inducible defenses, prey must gauge risk based on indirect cues of predation. However, the information contained in indirect cues that enable prey to fine-tune their phenotypes to variation in risk is still unclear. In aquatic systems, research has focused on cue concentration as the key variable driving threat-sensitive responses to risk. However, while risk is measured as individuals killed per time, cue concentration may vary with either the number or biomass killed. Alternatively, fine-grained variation in cue, that is, frequency of cue pulses irrespective of concentration, may provide a more reliable signal of risk. Here, we present results from laboratory experiments that examine the relationship between red-eyed treefrog tadpole growth and total cue, cue per pulse, and cue pulse frequency. We also reanalyze an earlier study that examined the effect of fine-grained variation in predator cues on wood frog tadpole growth. Both studies show growth declines with increasing cue pulse frequency, even though individual pulses in high-frequency treatments contained very little cue. This result suggests that counter to earlier conclusions, tadpoles are using fine-grained variation in cue arising from the number of predation events to assess and respond to predation risk, as predicted by consumer–resource theory.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.