Temporal and geographical genetic variability in Namaqua and Burchell's Sandgrouse

Abstract

Sandgrouse of southern Africa occur in semi-nomadic flocks which show opportunistic responses to unpredictable food and water availability. To test whether flock fidelity leads to genetic differentiation among flocks, we examined the products of 37 enzyme-encoding loci in 215 Namaqua and 106 Burchell's Sandgrouse with electrophoretic methods. Both species showed average or above average levels of gene diversity over samples:H= 0·076 in Namaqua Sandgrouse andH= 0·058 in Burchell's Sandgrouse. In Namaqua Sandgrouse, no significant allele-frequency differences were found among four localities scattered over 1000 km, and Nei's genetic distances between pairs of samples were less than 0·004. However, significant differences were detected between days and between months at some localities for one locus in each case. Waples' test for temporal differences between years was significant forMPI-1at Rooipoort and forPEP-Cat Nossob. In Burchell's Sandgrouse, significant regional heterogeneity among samples was detected forPEP-DandPGD-1, and genetic distances between samples were 0·018 or less. Significant allele-frequency differences between months for two loci at Rooipoort and between years appeared for another locus at Nossob. The results show either that flock fidelity is sufficient in these species of sandgrouse to produce weak, but significant genetic differences among flocks, or that birds from families within flocks were sampled.