Predators affect prey populations not only by prey consumption but also in nonconsumptive ways including modifying prey behavior. I tested the effects of fire salamander larvae (Salamandra infraimmaculata) on populations of co-occurring crustacean species in artificial outdoor pools. I also tested whether these effects were due entirely to prey consumption by Salamandra larvae or alternatively to some nonconsumptive effect. The soil (containing crustacean eggs) added to the artificial pools was collected from a dried-out temporary pool that is inhabited by Salamandra during the early part of the hydroperiod. I randomly assigned the pools to one of three treatments: control, free Salamandra, or caged Salamandra. Free salamander larvae could roam the entire pool and prey upon crustaceans. Caged salamander larvae were placed within a cage with having 250-μm mesh windows. They could not prey upon the crustaceans but could, for example, influence them by chemical cues. Densities of the three dominant crustacean species (Arctodiaptomus similis, Ceriodaphnia quadrangula and Cyzicus sp.) were drastically reduced in both salamander treatments compared to the control. Crustacean densities, however, were not significantly different between the two salamander treatments. One plausible explanation is that crustacean eggs can detect the presence of this predator via chemical cues and delay hatching.
|Number of pages||6|
|State||Published - 1 Apr 1997|
Bibliographical noteFunding Information:
Acknowledgements I gratefully acknowledge the Israel Nature Reserves Authority for permission to conduct research on the fire salamander, an endangered species in Israel. Robert Ditzion, Ellen Steiner and members of the course ‘‘Principles of Ecological Research’’ assisted with field work. I benefited from discussions with Michael Warburg, Gad Degani, Chanan Dimentman, and Joel S. Brown. Anurag Agruwal, Amos Bouskila, Rick Karban, Burt Kotler, Marc Mangel, Andy Sih and two anonymous reviewers kindly read and improved the manuscript. This study was partially funded by a joint Israel Ministry of Science-GSF (For-schungszentrum fuer Unwelt und Gesundheit GmbH, Nuerher-berg) grant number 1426 awarded to L. Blaustein, B. Breckling and E. Nevo.
- Induced response
- Temporary pools
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics