Biogeographic Patterns of Lemur Species Richness and Occurrence in a Fragmented Landscape

Dr Travis Steffens, will present the Department of Archaeology seminar with a talk entitled, "Biogeographic Patterns of Lemur Species Richness and Occurrence in a Fragmented Landscape". 

Dr Steffens received is PhD from the University of Toronto, is the founding Director of Planet Madagascar, and is an International Fellow of the Explorers Club. Dr. Steffens research focus is on theoretical and applied primate conservation biogeography. His specific research topics are multi-scale lemur community and species responses to habitat loss and fragmentation. Outside of theoretical research Dr. Steffens is dedicated to community conservation and development efforts, and environmental education, in rural communities in Madagascar

Determining the factors that affect species richness and occurrence is vital to the study of primate biogeography. I investigated the biogeographic patterns of a lemur community using the species-area relationship and individual lemur species using metapopulation dynamics and landscape ecology within a fragmented landscape in Ankarafantsika National Park, Madagascar. The landscape consists of 42 deciduous dry forest fragments ranging in size from 0.23 to 117.7 ha. I conducted lemur and vegetation surveys using standard methods, measured human disturbance metrics, and fragment isolation for each fragment. I found that lemurs in a fragmented landscape show a species-area relationship in the form of a convex power model and not the expected sigmoidal pattern. I found no evidence of a “small island effect.” Human disturbance and tree height also influence species richness. Lemur species form different metapopulations within the same landscape. Metapopulation dynamics suggest that area was a stronger factor determining individual lemur species occurrence than fragment isolation. However, for Microcebus species, area seems to have less influence than for other species (Cheirogaleus medius and Eulemur fulvus). Lemur species show species-specific scale responses to habitat amount. At a landscape-level area predicted species occurrence for C. medius and M. murinus, but not for M. ravelobensis. M. ravelobensis occurrence may be mediated by factors other than area, such as dispersal ability and edge tolerance. My study shows the importance of a multi-scale approach to lemur biogeography and how it is critical for understanding how lemur species respond forest loss and fragmentation.

Mon, 08 May 2017 - 13:00

Archaeology Department Teaching Studio, B3.10, Beattie Building, University Avenue, Upper Campus, UCT