Choice of Lookout Posts by Territorial Amberwing Dragonflies, Perithemis tenera (Anisoptera: Libellulidae)

Abstract

Many territorial insects use specific perches, or lookout posts, from which they perceive and react to conspecific males and females. We investigated the lookout post choice of territorial male amberwing dragonflies (Perithemis tenera). An observational study indicated that males rarely perched directly at their oviposition site; rather, they perched farther out from shore than, and within 2 m from, their oviposition site. In an experimental study, we provided an array of perches at different distances from the shore and oviposition site to eliminate perch limitation as a factor in perch choice. The results of the experimental study confirmed the patterns evident in the observational study; males perched farther from shore than their oviposition site was located. Interestingly, in both the observational and the experimental study, when neighbors were close, a male perched away from his closest neighbor, which usually resulted in his oviposition site being closer to his neighbor than he was. Thus, male amberwings apparently alter their perch choice within their territories in response to the location of other males. These lookout post locations may provide the best opportunity for the territorial male to perceive passing females and intruding males, while minimizing conflict with their neighbors.