SMALL IN A BIG WORLD: ECOLOGY OF LEAF-LITTER GECKOS IN NEW WORLD TROPICAL FORESTS

Abstract

We studied the ecology of four species of closely related leaf litter geckos, Coleodactylus amazonicus, C. septentrionalis, Lepidoblepharis xanthostigma, and Pseudogonatodes guianensis in tropical rainforests of Brazil and Nicaragua. All are found in leaf litter of undisturbed tropical forest where mean hourly surface temperatures vary from 23.5-29.1 C. Surface temperatures, where individual C. amazonicus were found, averaged 27.4 C and air averaged 29.9 C. Coleodactylus amazonicus was the smallest species and L. xanthostigma was the largest. The latter was the most different morphologically as well. Tail loss rates varied from 45.5-81.8% among species. All four species ate very small prey items, largely springtails, homopterans, termites, small insect larvae, and spiders. Nevertheless, considerable differences existed among species. Some variation existed among populations of C. amazonicus. Prey size was correlated with lizard SVL within and among species. All four species are typically the smallest species in their respective lizard assemblages. Small body size may have consequences for predation. Partially due to small body size, these lizards are vulnerable to extirpation resulting from effects of tree removal on thermal attributes of their leaf litter environment.