Territoriality in the poison-dart frog Dendrobates pumilio (Anura: Dendrobatidae).

摘要

Territoriality has been observed in several species of anuran amphibians and is best understood in the context of intraspecific competition for some limited resource. The object of defense and its availability in nature must be determined to understand fully the ecological implications of the behavior. I increased the availability of tadpole-rearing sites (bromeliads) and oviposition substrates (leaf litter) to determine if these resources were the object of male defense in the strawberry poison-dart frog Dendrobates pumilio.; The addition of litter did not result in increased adult density however the addition of bromeliads led to an increase in the density of adult males and adult females. Demographically, the increase in the number of males resulted from increased survivorship on treatment plots whereas the increase in female density resulted from increased immigration rates. The population-level response suggests that bromeliad availability is limited and this resource is defended by males. These results are discussed in the context of the reproductive behaviors of both adult males and females.; Population density is one factor influencing space-use patterns in vertebrates. Home range size, overlap, and dispersion pattern were unaffected by the addition of the reproductive resources. These results indicate that increased numbers of adults on bromeliad addition plots are accomodated by additional animals utilizing unoccupied space. The addition of bromeliads enhanced the quality of the plots and additional animals were able to utilize habitat that was marginal prior to the addition of the supplemented resource. The sexes differ in the size of the home range; females have larger home ranges. The size of the "defended area" is significantly smaller than male home range and implies that it is not economical for males to defend the entire area.