Populations of Chihuahuan Desert spiders that construct webs in naturally occurring cavities were followed over a 20-week-period with modified pitfall traps. Of the three species studied, Psilochorus imitatus (Pholocidae) was the most abundant, followed in order by Artema atlanta (Pholocidae) and Latroductus hesperus (Theridiidae). Canonical correlation analysis indicated a strong dependence of L. hesperus upon soil temperatures. A principal axis factor analysis explained 87 per cent of the variance in the spider-weather-habitat aspect system with five common factors. This model also gave a good fit to all monitored variables. This analysis demonstrated the importance of habitat aspect upon spider distributions, and allowed an examination of the partitioning of niche space by the three species. Experimental laboratory manipulations suggested that groups of A. atlanta can behaviorally dominate solitary L. hesperus females by restricting orb web construction, and suggested that patterns observed in the field may be shaped by interspecific competition.