The impacts of selective logging on three sympatric species of Leptodactylus in a Central Guyana rainforest

Abstract

Selective logging has the potential to significantly alter environmental conditions experienced by both larval and adult amphibians and, therefore, may affect the population viability of particular species. In this study we evaluated the impacts of selective logging on the occurrence, larval development, and survival of three sympatric foam nest-constructing Leptodactylus species in a central Guyanan rainforest. The occurrence and abundance of adults differed among species and between habitat complexes. Species-habitat associations appeared to be linked to species-specific reproductive habitat requirements. The response of tadpoles to logging-related habitat alterations varied among species. Experiments on one of the focal species showed that tadpole development and growth depend on larval residence time within foam nests, and on environmental factors related to solar exposure and temperature of aquatic habitats. Tadpoles that were reared in foam nests over extended periods of time showed significant decrease in body mass. Tadpoles reared under exposed conditions developed more slowly than those reared under shaded conditions. Likewise, larval growth decelerated in the former. Larval survival differed among species and between habitats. Species-specific responses to disturbance-related environmental changes indicate that simplified generalizations that do not take into account species-specific variation are problematic. We, therefore, argue that sound conservation strategies for this group of amphibians would benefit by moving from generalizations to species specific recommendations. © 2007 Brill Academic Publishers.