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

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Michael W. McCoy (Creator)

James R. Vonesh (Creator)

Karen M. Warkentin (Creator)

Stefan K. Wheat (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

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.

Additional Information

Publication

Other

Language: English

Date: 2015

Keywords

Inducible defense, Tadpole, Predation, Phenotypic plasticity

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