Data from: Population divergence and gene flow in an endangered and highly mobile seabird

Seabirds are highly vagile and can disperse up to thousands of kilometers,
therefore it can be difficult to identify the factors that promote
isolation between populations. The endemic Hawaiian petrel (Pterodroma
sandwichensis) is one such species. Today it is endangered, and known to
breed only on the islands of Hawaii, Maui, Lanai, and Kauai. Historical
records indicate that a large population formerly bred on Molokai as well,
but this population has recently been extirpated. Given the great
dispersal potential of these petrels it remains unclear if populations are
genetically distinct and which factors may contribute to isolation between
them. We sampled petrels from across their range, including individuals
from the extirpated Molokai population. We sequenced 524 bp of
mitochondrial DNA, 741 bp from three nuclear introns, and genotyped 18
microsatellite loci in order to examine patterns of divergence in this
species and to investigate the potential underlying mechanisms.
Mitochondrial and nuclear data sets indicated significant genetic
differentiation among all modern populations, but no differentiation was
found between historic samples from Molokai and modern birds from Lanai.
Population-specific non-breeding distribution or perhaps strong natal
philopatry may reduce gene flow between populations. However, the lack of
population structure between extirpated Molokai birds and modern birds on
Lanai suggests that petrels may be able to overcome these barriers and
disperse prior to complete extirpation. Hawaiian petrel populations should
be managed as distinct units, except potentially for the dwindling
population on Hawaii, which may require translocation to prevent
extirpation in the near future.