The influence of multi-stage predation on population growth and the distribution of the pond-breeding salamander, Ambystoma jeffersonianum

Autor: Michael J. Rubbo, Joseph M. Kiesecker, Katriona Shea
Rok vydání: 2006
Předmět:
Zdroj: Canadian Journal of Zoology. 84:449-458
ISSN: 1480-3283
0008-4301
DOI: 10.1139/z06-015
Popis: Understanding the drivers of distributional patterns is a fundamental goal of ecology. For many organisms, distributions are determined by the habitats in which breeding occurs. Therefore, determining the factors that limit post-ovipositional success in specific habitats is critical to deciphering the factors that shape distributions. Using field surveys and laboratory, mesocosm, and field experiments, we conducted a study of the breeding effort of the salamander Ambystoma jeffersonianum (Green, 1827) in sites of varying predation pressure and the susceptibility of its embryos and larvae to predators. We then used these data to parameterize a matrix model examining the effects of predation on population growth. We found that A. jeffersonianum egg masses were less abundant in ponds with higher predation pressure. Moreover, A. jeffersonianum performance was negatively affected by both embryonic and larval predators. The results of the model suggest that only predation acting upon multiple life-history stages can limit population growth for A. jeffersonianum. These data provide support for the hypothesis that multi-stage predation can shape breeding distributions by imposing strong selective costs in specific environments. Furthermore, these data highlight the importance of conducting multi-stage studies and utilizing multiple ecological methodologies when addressing the factors that limit the distribution and abundance of organisms.
Databáze: OpenAIRE