Effects of prey size and foraging mode on the ontogenetic change in feeding niche of Colostethus stepheni (Anura: Dendrobatidae) / Albertina P. Lima.

Dissertação (mestre) - INPA/UFAM, 1992

The feeding niche of Colostethus stepheni changes during ontogeny. Small individuals eat small arthropods that are principally mites and collembolans, and larger frogs eat bigger prey of other types. The shift in prey types is not a passive effect of selection for bigger prey types and frog size, independent of electivity for prey size. Four indices of general activity during foraging (number of movements, velocity, total area utilized and percent of time moving), which are associated with electivity for prey types in adult frogs and lizards, did not predict the ontogenetic change in the diet of C. stepheni. Apparently, the behavioral changes that cause the ontogenetic change in C. stepheni are more subtle than shifts in general activity during foraging. Studies on niche partioning in communities of anurans that do not take into consideration ontogenetic changes in diet and seasonal changes in the size structures of populations present a partial and possibly erroneous picture of the potential interactions among species.

Área de concentração: Ecologia.