POPULATION-STRUCTURE OF AFRICAN BUFFALO INFERRED FROM MTDNA SEQUENCESAND MICROSATELLITE LOCI - HIGH VARIATION BUT LOW DIFFERENTIATION

The African buffalo (Syncerus caffer) is widespread throughout sub-Sah aran Africa and is found in most major vegetation types, wherever perm anent sources of water are available, making it physically able to dis perse through a wide range of habitats. Despite this, the buffalo has been assumed to be strongly philopatric and to form large aggregations that remain within separate home ranges with little interchange betwe en units, but the level of differentiation within the species is unkno wn. Genetic differences between populations were assessed using mitoch ondrial DNA (control region) sequence data and analysis of variation a t six microsatellite loci among 11 localities in eastern and southern Africa. High levels of genetic variability were found, suggesting that reported severe population bottlenecks due to outbreak of rinderpest during the last century did not strongly reduce the genetic variabilit y within the species. The high level of genetic variation within the s pecies was found to be evenly distributed among populations and only a t the continental level were we able to consistently detect significan t differentiation, contrasting with the assumed philopatric behaviour of the buffalo. Results of mtDNA and microsatellite data were found to be congruent, disagreeing with the alleged male-biased dispersal. We propose that the observed pattern od: the distribution bf genetic vari ation between buffalo populations at the regional level can be caused by fragmentation of a previous panmictic population due to human activ ity, and at the continental level, reflects an effect of geographical distance between populations.