Web Orientation by Nephila clavipes in Southeastern Texas

Abstract

-We undertook a longitudinal study of marked free-living individuals of the orb-weaving spider Nephila clavipes (Linnaeus), investigating the importance of individual web-site structure in determining the orientation of the web. A new method of analyzing pairwise circular data allowed comparisons of successive webs at a given site or by a given spider. Successive webs by the same spider at the same site were oriented in the same direction and successive, nonoverlapping occupants of the same site oriented their webs in the same direction. Additionally, spiders that built in aggregations of webs tended to orient their webs in the same direction. However, as an individual changed web sites, the orientation of webs at successive sites were not correlated. The analysis of orientation within each microhabitat revealed slightly significant correlations of web orientations, but there was no correlation of web orientations over the entire population. We conclude that the conditions at individual web sites were the dominant factor in determining the orientation of webs at this location.