Edaphically-biased distributions of amphibians and reptiles in a lowland tropical rainforest

Abstract

I surveyed amphibians and reptiles in primary forest growing on two different soil types in northeastern Costa Rica to determine if animals showed edaphically-biased distribution patterns. Species composition of the herpetofaunal assemblage and the density of two of the four most abundant species in the sample differed significantly between soil types. There were no differences in multivariate habitat profiles between the two soil types, and species composition was not related to habitat characteristics. The density of one species (Dendrobates pumilio) was negatively related to leaf litter cover. The distribution of D. pumilio, a diet specialist, did not appear to be related to the distribution of arthropod prey items. While these data suggest that amphibian and reptile density varies between edaphically-differentiated forest types at this site, the mechanisms generating observed distribution patterns remain unclear.