Patterns of Territoriality and Mating Success in the White-Tailed Skimmer Plathemis lydia (Odonata: Anisoptera)

Abstract

We studied the behavioral ecology of Plathemis lydia Drury (Odonata: Anisoptera) in central coastal California during summer 1983. Oviposition peaked in the early afternoon, was fairly synchronous, and varied sptially, with females avoiding a sandbar and preferring the deepest section of the pond. Only 79% of males known to be alive visited the pond any particular day. Those that did come were territorial, nonterritorial "poachers", or often both when within the same day. Territories were always defended individually and individual males were territorial for only a few hours in any one day, even though mating success was considerably higher for territory holders. Daily mating success of males was estimated based on the time, place and duration of territorial behavior. Estimated daily mating success correlated significantly with wing condition and body length. The components of mating success we measured all correlated with one another; thus, we found no evidence that tradeoffs occurred either among components of daily mating success or between estimated daily mating success and survivorship.