Settling decisions of dispersing Stegodyphus Lineatus (eresidae) young

Dispersal and site selection determine the distribution of organisms in relation to habitat features. Natal philopatry and specific habitat requirements may result in a clumped distribution that may have important consequences for population structure. We investigated dispersal of young of the web-building spider Stegodyphus lineatus (Eresidae), which has a highly clumped distribution in dry watercourses (wadis) in the Negev Desert. The young dispersed from maternal nests in late summer to a median distance of only 2 m, and the dispersal directions differed among families and sites. More than 80% of the young settled in four species of perennial shrubs, a distribution that differed significantly from expected from the relative abundance of these shrubs in the habitat. Occupied shrubs were taller and had larger surface areas than unoccupied ones nearby. We suggest that the limited movement of young during dispersal and their preference for certain types of shrubs results in a clumped distribution.