Habitat structure is one of several factors influencing animal distribution patterns. Spiders, in particular, are widely known to be influenced by habitat structure. Some of the structural parameters spiders respond to include vegetation height, density, and orientation.  Although spiders respond to various components of vegetation architecture, it remains unclear whether spiders are actually responding to architecture, per se, or to differences in prey availability associated with different architectures. Here, the effects of prey availability and shrub architecture and their interactions on spider abundances were examined. Big sagebrush shrubs (Artemisia tridentata) were randomly assigned to six experimental treatments, with each treatment consisting of twenty five shrubs. Treatments consisted of two levels of insect attractant (shrubs that were either baited or not baited) and three levels of foliage density (low, natural/control, or high foliage density shrubs). Sampling was conducted four times during 2007.

Results/Conclusions

A total of 4,540 spiders were collected, representing near 40 species and 11 families, including members from Araneidae, Dictynidae, Gnaphosidae, Linyphiidae, Lycosidae, Mimetidae, Oxyopidae, Philodromidae, Salticidae, Theridiidae, and Thomisidae. Spider abundance was highest in July, followed by August and September, with June having the lowest number of spiders. Early results suggest that both prey availability and shrub architecture influence spider abundances. More spiders were collected on baited shrubs whether they were high foliage density or natural/control shrubs, with the high foliage density shrubs having the most spiders.