THE EFFECTS OF SIZE ON THE DIETS OF 6 SYMPATRIC SPECIES OF POSTMETAMORPHIC LITTER ANURANS IN CENTRAL AMAZONIA

All species of diurnal leaf-litter anurans in central Amazonia changed the type and size of their prey as they grew. Postmetamorphic individ uals of all species ate principally mites and collembolans, and larger frogs ate larger prey of other types. The shift in prey types was not a passive effect of selection for larger prey. There was a strong rel ationship between electivity for prey types and frog size, independent of electivities for prey size, in six of the seven species. This stud y showed that most species in the community had strong ontogenetic cha nges in diet composition and electivity for prey types, and these chan ges did not conform to simple models of the effects of predator size a nd diet quality.