Neighborhood effects on territorial aggregations of the burrowing wolf spider Geolycosa xera archboldi McCrone (Araneae: Lycosidae)

Abstract

The effects of territorial neighbors on the foraging success of a burrowing wolf spider, Geolycosa xera archboldi McCrone, were examined in the field in central Florida, U.S.A. The rates of mass gain by juveniles were quantified and related to the following burrow neighborhood characteristics: mean nearest-neighbor size, mean nearest-neighbor distance, and mean number of neighbors within 1 m of the focal animal's burrow. Only nearest-neighbor size was correlated (negatively) with mass gain. Field tests with provisioned prey showed that larger neighbors were both more likely to take prey in a zone of territorial overlap and to do so sooner than smaller neighbors. Tests for exploitative competition using paired adhesive traps to mimic pairs of neighboring spiders were conducted at the mean nearest-neighbor distance for the population (30 cm) to model territorial dyads and pairs of traps at random smaller distances to model nonterritorial dyads. There was no difference in rates of prey capture by pairs of traps at the territorial distance and the shorter distances, indicating that resource depletion may not explain the patterns observed.