Animal feeding ecology and diet are influenced by the fear of predation. While the mechanistic bases for such changes are well understood, technical difficulties often prevent testing how these mechanisms interact to affect a mesopredator's diet in natural environments. Here, we compared the insectivorous lizard Acanthodactylus beershebensis' feeding ecology and diet between high- and low-risk environments, using focal observations, intensive trapping effort and fecal pellet analysis. To create spatial variation in predation risk, we planted "artificial trees" in a scrubland habitat that lacks natural perches, allowing avian predators to hunt for lizards in patches that were previously unavailable to them. Lizards in elevated-risk environments became less mobile but did not change their microhabitat use or temporal activity. These lizards changed their diet, consuming smaller prey and less plant material. We suggest that diet shifts were mainly because lizards from risky environments consumed prey items that required shorter handling time.
Bibliographical noteFunding Information:
Acknowledgements We thank Z. Abramsky and A. Bouskila who contributed substantially to the development of this research and J. Richardson, H. Jones, O. Schmitz, and three anonymous reviewers for helpful comments. We are indebted to all Weld assistants and to Z. Ortega for laboratory assistance. This research was supported by an International Arid Land Consortium grant (99R-10) to A. Bouskila, by the Gaylord Donnelley Environmental Fellowship to D. H. and by the CGL2006-10893-CO2-02 grant to V. P. M. The study was carried out with the appropriate permits from the Israeli Nature and Parks Authority.
- Acanthodactylus beershebensis
- Crossover hypothesis
- Handling time