Responses of Resident Male Dendrobates pumilio to Territory Intruders

Abstract

Male Dendrobates pumilio are territorial, and vocalize in the presence of intruders. Territory displays are energetically expensive, and residents should modify display behavior according to costs and benefits associated with social contexts of intrusions by conspecifics. Activity censuses found no significant difference in the proportions of male and female D. pumilio found at various times of day, but a higher proportion of animals that were active at 0730 were male. Resident males exhibited a significantly greater mean call group duration when faced with male intruders in the morning than in the afternoon but did not respond differently to male or female intruders. This may reflect greater potential benefits of repelling territorial intruders in the morning than in the afternoon and use of the same territorial displays to defend territory boundaries as well as to attract potential mates. No significant differences were found in responses of resident males to familiar and unfamiliar conspecifics, which suggests that both neighbors and strangers may compete with residents for territory and mates.