The Herpetological Journal

pp. 45-48
Authors: Costa, Gabriel C.; Mesquita, Daniel O. & Colli, Guarino R.

Abstract: Pitfall trapping is a widely used sampling method in amphibian and reptile studies. Despite their broad use and numerous advantages, the question of whether diets of trapped animals differ from those under natural conditions remains uninvestigated. We use data on eight lizard species to test the hypotheses that lizards captured in pitfall traps differ in diet composition and/or have higher stomach content volumes when compared to lizards collected using other methods. The basis for these hypotheses is that many common lizard prey items fall into the traps and are thus available to trapped lizards. Testing these hypotheses is critical to validate the results of diet studies that use animals taken from pitfall traps. Our results showed that lizards collected from pitfall traps did not differ significantly from lizards collected outside the traps in diet composition or volume of prey consumed. However, two species (among eight) had different stomach content volumes inside the traps; one (Anolis chrysolepis) had a higher volume and the other (Tropidurus oreadicus) had a lower volume. For the species we studied, we found that lizards collected with pitfall traps can be used in diet studies. Nevertheless, we recommend checking traps at least once a day to avoid prolonged exposure to different prey items, collecting large sample sizes, and also collecting animals outside the traps.

Keywords: NICHE OVERLAP, TEIIDS, FORAGING BEHAVIOR, IGUANIDS, FOOD SELECTION