Breeding populations of northern pintails have similar mitochondrial DNA

Northern pintails (Anas acuta) are highly nomadic, which may result in
high levels of gene flow among nesting areas. To assess the extent of genetic
differentiation among nesting areas, we analyzed mitochondrial DNA (mtDNA)
variation in northern pintail females from three regions: Alaska, California,
and midcontinent prairies and parklands. Abundant mtDNA variation was evident
(20 genotypes among 289 birds), but there was no significant genetic
differentiation of nesting areas within or among regions. Results indicate that
pintails have had historically large breeding population sizes and a high rate
of gene flow among North American nesting areas. Specific nesting areas are not
independent units, but part of a larger continental population. High rates of
gene flow suggest that over time, localized reductions in recruitment or
survival may be compensated for by immigration.