The Herpetological Journal

pp.252-256

Authors: Sergius L. Kuzmin

Abstract: Competition occurs when resources are limited and may be determined only by its effects on the component species. It must change the condition ofresources and the fitness of competitors (or at least part of them) so that both are negatively affected. Original data and analysis of the literature revealed that food competition in amphibians is usually discussed in terms of (1) negative interactions between individuals; (2) density-dependent responses of individuals; (3) density-dependent responses without estimation of food resources; (4) differences in the biology of syntopic species; (5) feeding rate variability; (6) the impact of amphibians on their food resources; and (7) density-dependent responses with estimation of food resources. Food competition can only be identified in the last case, where depletion of food resources is demonstrated together with negative interactions between species. Such events have been demonstrated in some laboratory or microcosm experiments, but not in nature. Food competition appears to be rather rare in natural guilds of amphibians.