Food Habits of Invasive Bullfrogs and Native Thin-Toed Frogs Occurring in Sympatry in Southeastern Brazil

Abstract

Abstract. Although the feeding ecology of sympatric anurans has been studied, less is known about the food habits of co-occurring invasive and native frog species, particularly in the Neotropics. We compared the food habits of invasive bullfrogs (Lithobates catesbeianus) and native thin-toed frogs (Leptodactylus cf. latrans) in a locality of Southeastern Brazil. Monthly field surveys and stomach content analyses were performed between September 2008–April 2009 and September–November 2009. Prey items were identified to the lowest taxonomic level and diet overlap was estimated. Juveniles of both species had similar body sizes, but adult thin-toed frogs were smaller than adult bullfrogs. Insects and spiders dominated the diets of juveniles of both species and of adult thin-toed frogs, whereas anurans and water bugs predominated in adult bullfrog diets. Thin-toed frogs consumed a larger number of prey items than bullfrogs, which in turn consumed more voluminous prey items. Aquatic and amphibious prey items we...