Male Dendrobates pumilio return home if displaced, suggesting that their vocal behaviors maintain territories. Many females are also site specific, perhaps because involved in parental care. Observations concerning mating behavior suggest that some D. pumilio are at times polygynous. RECENT studies relating ecology to social behavior and mating systems in anuran amphibians reveal an impressive diversity of social systems (Emlen, 1976; Wells, 1977a, b). Careful characterization of such systems are not available for most species, however. In species with vocal, hyperdispersed males, behaviors have been labeled as individual avoidance or territoriality when data to distinguish between these two superficially similar systems are lacking (Wells, 1977a). This study of Dendrobates pumilio was therefore designed to 1) test for territoriality and 2) provide a preliminary description of some breeding behaviors. D. pumilio, a "poison dart" frog (Meyers and Daly, 1976), is common in the Atlantic lowland tropical forests of Central America. It is diurnal and forages for small insects in leaf litter (Limerick, 1976). Both sexes are bright red with purple-blue legs and contain alkaloids in the skin (Albuquerque et al., 1971; Meyers and Daly, 1976). Males call from logs and tree bases. When such sites are evenly distributed on the forest floor, males appear to be hyperdispersed (Bunnell, 1973). Females lay eggs in moist leaf litter or under logs (Savage, 1968). Adults carry tadpoles from the ground to water-filled bromeliads (Starrett, 1960). Both males and females are reported to carry tadpoles (Kitasako, 1967; Silverstone, 1975; Wells, 1977b). Individual males remain in the same spot for many days and occasionally attack approaching intruders (Bunnell, 1973). Aggressive behaviors can be provoked by playing male calls through a speaker 1-2 m from a calling male (Bunnell, 1973), but such provocation does not
