The ecology of the web ofUloborus diversus (Araneae: Uloboridae)

The distribution ofUloborus diversus webs around pack rat nests on the desert near Cave Creek, Arizona, differences between webs there and in nearby residential Phoenix, and differences between the webs of large and small individuals indicate that these spiders select web sites and designs to minimize web damage by wind. The frequency of web construction decreased when spiders in captivity were exposed to wind or to relatively bright (5 Lamberts) nights. Observations of web sites on the desert revealed high rates of web-turnover and substantial frequencies of movements of spiders from one site to another. Much lower rates of web-turnover and spider movement occurred in less windy situations in the laboratory, and in suburban Phoenix. Partial web replacement and the extension of web construction over two nights are apparently methods used to improve catching ability of sheltered (longer lived) webs by extending their surface and/or tightening their mesh.