Feeding Ecology of Panamanian Litter Anurans: Patterns in Diet and Foraging Mode

Abstract

Litter frogs at two rainforest locations in Panama elect prey in a pattern similar to that found for litter frogs in lowland Peru (Toft, 1980) despite differences in the frog fauna between Panama and Peru. Species of litter frogs form a continuum from species that specialize on ants and mites, through generalists, to species that avoid ants and mites. Modes of foraging and predator defense and taxa of litter frogs are correlated with position along the continuum. Atelopus and Bufo (Bufonidae) and Dendrobates (Dendrobatidae) are poisonous, searching foragers which eat many small prey, primarily ants and mites, per day. Colostethus (Dendrobatidae) eat ants, but to a lesser degree, and have a more sedentary foraging behavior than Dendrobates. Eleutherodactylus (Leptodactylidae) are cryptic, sit-and-wait foragers which eat few large prey per day, with the exception of E. vocator, which eat ants in proportion similar to Colostethus. Evidence within the Dendrobatidae suggests that specialization on ants is derived from a generalized mode of foraging. Ecological correlates of foraging mode in litter anurans are summarized and are generally similar to