Population genetics of the African buffalo : from ecology to evolution

The African buffalo ( Syncerus caffer ) is one of the most numerous mammals of sub-Saharan Africa. Since the end of the 19th it has been affected by rinderpest epidemics and by habitat fragmentation due to increasing urbanisation and cultivation. In this thesis the genetic diversity of the African buffalo is investigated. A better knowledge of the population genetics of the African buffalo is necessary for an effective management and protection of this species. The goals of this thesis were to study the effects of rinderpest and habitat fragmentation on the genetic diversity of buffalo populations, as well as the evolutionary history and herding behaviour of the African buffalo. Three types of genetic markers are used: autosomal microsatellites, Y-chromosomal microsatellites and mitochondrial DNA (mtDNA) D-loop sequences. Compared to other mammals buffalo populations show a high genetic diversity and little genetic differentiation for autosomal microsatellites and mtDNA. From the high genetic diversity it is concluded that rinderpest epidemics and habitat fragmentation had little effect on genetic diversity. The little population differentiation is attributed to a Pleistocene population expansion. Among herds significant differentiation is observed at mtDNA, while among neighbouring populations there are indications that there is relatively little genetic substructuring at autosomal microsatellites. These data support the field observations of male biased dispersal between herds. Buffalo from central and south-western Africa form a separate genetic lineage from those in eastern and southern Africa. Genetic diversity of the first lineage is relatively high for all three types of markers. It is suggested that this is due to fragmentation of wet habitats as a result of climatic changes in the evolutionary past. Finally, it is discussed how the results of this thesis can be used for a more effective management and protection of the African buffalo