Negative synergism of rainfall patterns and predators affects frog egg survival
Article first published online: 8 APR 2009
© 2009 The Authors. Journal compilation © 2009 British Ecological Society
Journal of Animal Ecology
Volume 78, Issue 4, pages 715–723, July 2009
How to Cite
Touchon, J. C. and Warkentin, K. M. (2009), Negative synergism of rainfall patterns and predators affects frog egg survival. Journal of Animal Ecology, 78: 715–723. doi: 10.1111/j.1365-2656.2009.01548.x
- Issue published online: 4 JUN 2009
- Article first published online: 8 APR 2009
- Received 6 September 2008; accepted 9 March 2009Handling Editor: Shai Meiri
- complex life cycle;
- Hyla ebraccata;
- interaction modification;
- predator–prey interaction
- 1The importance of rainfall is recognized in arid habitats, but has rarely been explored in ecosystems not viewed as rainfall limited. In addition, most attempts to study how rainfall affects organismal survival have focused on long-term rainfall metrics (e.g. monthly or seasonal patterns) instead of short-term measures. For organisms that are short lived or are sensitive to desiccation, short-term patterns of rainfall may provide insight to understanding what determines survival in particular habitats.
- 2We monitored daily rainfall and survival of arboreal eggs of the treefrog Dendropsophus ebraccatus at two ponds during the rainy season in central Panama. Desiccation and predation were the primary sources of egg mortality and their effects were not independent. Rainfall directly reduced desiccation mortality by hydrating and thickening the jelly surrounding eggs. In addition, rainfall reduced predation on egg clutches.
- 3To elucidate the mechanism by which rainfall alters predation, we exposed experimentally hydrated and dehydrated egg clutches to the two D. ebraccatus egg predators most common at our site, ants and social wasps. Ants and wasps preferentially preyed on dehydrated clutches and ants consumed dehydrated eggs three times faster than hydrated eggs.
- 4Rainfall patterns are expected to change and the responses of organisms that use rainfall as a reliable cue to reproduce may prove maladaptive. If rainfall becomes more sporadic, as is predicted to happen during this century, it may have negative consequences for desiccation-sensitive organisms.