No abstract

Although studies have explored how habitat structure and disturbance affect arthropod communities, few have explicitly tested the effects of both structure and disturbance level across trophic levels and phyla. We present here the results of a study conducted in the Arabuko‐Sokoke Forest (ASF) of coastal Kenya, in which abundance of arthropods and one of their avian predators, the East Coast Akalat Sheppardia gunning sokokensis was compared in relatively undisturbed habitat (outside elephant roaming areas) and in disturbed habitat (inside elephant roaming areas). Vegetation structure in both areas was measured using several metrics, including leaf litter depth, understory vegetation density, animal disturbance and fallen log counts. Leaf litter and coleopteran abundance were higher outside the elephant roaming areas, whereas understory visibility, animal disturbance and dipteran diversity were much higher inside the elephant areas. Species composition of several arthropod taxa (e.g. Hymenoptera, Coleoptera, Diptera, Hemiptera and Araneae) was also influenced by degree of disturbance, whereas akalat abundance was inversely related to understory visibility. Our results suggest that differences in species sensitivity to habitat disturbance and vegetation structure across trophic levels should be incorporated into the management and conservation of rare and endangered species.

The management of assemblages of species across many taxa is a common concern in conservation. Consequently, the use of one or a few surrogate or indicator species to represent an entire assemblage has become an increasingly important tool in conservation science. However, conservation schemes based on the needs of one or two focal species often fail to account for individualistic responses of larger assemblages of species. Data from bird point counts along with vegetation characteristics from a coastal tropical dry forest in Kenya that is subject to elephant disturbance were used to explore the differential responses of bird species to environmental conditions in a forest reserve where wildlife management includes both endangered birds and mammals. Results revealed that even birds with similar foraging habits had idiosyncratic responses to both environmental traits and elephant disturbance. While overall species responded to important characteristics such as percent canopy cover and leaf litter depth, individualistic responses of different species trait diversity defied easy characterization of optimal forest management schemes. Taken together, our analyses highlight the difficulty in basing the development of management plans for entire assemblages of species on the response of a single or a few species. Implications for wildlife conservation in Arabuko-Sokoke Forest and similar forest reserves are discussed, emphasizing the need for a better understanding of individual species' responses to forest conditions.