Data from: Contrasting historical and recent gene flow among African buffalo herds in the Caprivi Strip of Namibia

Population genetic structure is often used to infer population
connectivity, but genetic structure may largely reflect historical rather
than recent processes. We contrasted genetic structure with recent
gene-flow estimates among 6 herds of African buffalo (Syncerus caffer) in
the Caprivi Strip, Namibia, using 134 individuals genotyped at 10
microsatellite loci. We tested whether historical and recent gene flows
were influenced by distance, potential barriers (rivers), or landscape
resistance (distance from water). We also tested at what scales
individuals were more related than expected by chance. Genetic structure
across the Caprivi Strip was weak, indicating that historically, gene flow
was strong and was not affected by distance, barriers, or landscape
resistance. Our analysis of simulated data suggested that genetic
structure would be unlikely to reflect human disturbances in the last
10–20 generations (75–150 years) because of slow predicted rates of
genetic drift, but recent gene-flow estimates would be affected. Recent
gene-flow estimates were not consistently affected by rivers or distance
to water but showed that isolation by distance appears to be developing.
Average relatedness estimates among individuals exceeded random
expectations only within herds. We conclude that historically, African
buffalo moved freely throughout the Caprivi Strip, whereas recent gene
flow has been more restricted. Our findings support efforts to maintain
the connectivity of buffalo herds across this region and demonstrate the
utility of contrasting genetic inferences from different time scales.