The demographic and life-history costs of fear: Trait-mediated effects of threat of predation on Aedes triseriatus

Authors

Geoffrey D. Ower
Steven A. Juliano, Illinois State UniversityFollow

Document Type

Article

Publication Title

Ecology and Evolution

Publication Date

3-2019

Keywords

carryover effects, chemical cues, life‐history traits, predation, trade‐offs, trait‐mediated effects

Abstract

1. Predators alter prey populations via direct lethality (density-mediated effects), but in many taxa, the indirect nonlethal threat of predation may be almost as strong an effect, altering phenotypically plastic traits such as prey morphology, behavior, and life history (trait-mediated effects). There are costs to antipredator defenses and the strength of prey responses to cues of predation likely depends on both the perceived level of risk and food availability.
2. The goal of this study was to test the hypothesis that the costs of nonlethal trait-mediated interactions impacting larvae can have carryover effects that alter life-history traits, adult characteristics, and ultimately population dynamics.
3. The effects of Toxorhynchites rutilus kairomones and chemical alarm cues on Aedes triseriatus were assessed in a two-level factorial design manipulating nutrient level (low or high) and chemical cues of predation (present or absent).
4. Nonlethal chemical cues of predation significantly decreased female survivorship and significantly decreased female size. Females emerged as adults significantly earlier when exposed to predation cues when there was high nutrient availability. When raised in the low nutrient treatment and exposed to predator cues, adult females had 2.1 times the hazard of death compared to high nutrient-no predator cues. Females raised in the high nutrient and predator cue treatment blood fed sooner than did females from other combinations.
5. Fear of predation can substantially alter prey life-history traits and behavior, which can cascade into dramatic population, community, and ecosystem effects. Exposure to predator cues significantly decreased the estimated cohort rate of increase, potentially altering the expected population density of the next generation.

Funding Source

National Institute of Allergy and Infectious Diseases, Grant/Award Number: 1R15AI094322‐01A1.

Comments

First published in Ecology and Evolution volume 9, issue 7 (March 2019). https://doi.org/10.1002/ece3.5003.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Recommended Citation

Ower, Geoffrey D. and Juliano, Steven A., "The demographic and life-history costs of fear: Trait-mediated effects of threat of predation on Aedes triseriatus" (2019). Faculty Publications – Biological Sciences. 142.
https://ir.library.illinoisstate.edu/fpbiosci/142

DOI

10.1002/ece3.5003