Habitat separation in a species-rich assemblage of jumping spiders (Araneae: Salticidae) in a suburban study site in Zimbabwe

Abstract

A 40-species assemblage of jumping spiders inhabiting a small (0.6 ha) tropical suburban study site in Zimbabwe was studied over 4 years. It was hypothesized that marked habitat separation is one of the critical factors permitting the close coexistence of so many species from the same family (Salticidae). The 25 most common salticids (i.e. species with 10 or more records) were found to occupy six primary habitat types: tree trunks (with three salticid species), tree leaves (two species), shrubs (five species), walls (three species), low herbaceous plants and grasses (three species) and ground and litter (six species). The remaining three species, termed habitat generalists, frequented three or more of these habitats. Finer-scale microhabitat separation was also recorded in many species. The remaining 15 less common species (i.e. <10 records) could not be assigned to particular habitats with certainty. Twenty-one (84%) of the 25 common salticids showed a significant association with a single primary habitat type. Three-quarters of species were present for 3 or 4 years of this 4-year study. It was concluded that the narrow spatial niches occupied by most species, combined with the numerous microhabitats within the site, were conducive to the highly diverse salticid assemblage. Attention is drawn to the problems of long-term sampling of such a small area without undue disturbance to the fauna. The impacts of long-term weather cycles on habitats, ephemeral niches, age-dependent use of habitats, inter- and intraspecific associations of individuals within habitats, and the relationship between suburban and wild habitats are discussed. Suburban environments, by providing a wide range of microhabitats, can support a high diversity of salticid species and thus contribute to their conservation.