Territoriality in the dragonfly Libellula saturata Uhler: mutual avoidance or resource defense? (Anisoptera: Libellulidae)

2 models of territoriality were compared in an observational study. The "mutual avoidance" model predicts that males should become more territorial as densities increase. The "resource monopolization” model proposes the opposite. Because some males were territorial throughout the season, even at low densities, the mutual avoidance model was rejected and the resource monopolization was supported. However, another prediction of the resource monopolization model is that if females are easily defended in space, then males benefit by being territorial. This prediction was not met. Mate-encounter points were randomly distributed. Thus it appears difficult for males to monopolize females, and yet some males were territorial throughout the season for reasons that remain to be identified.