Low levels of population structure among geographically distant populations of Pteropus vampyrus (Chiroptera: Pteropodidae)

Pteropus vampyrus, the largest bat in the world, has a broad geographic range covering much of Southeast Asia. The wide distribution of P vampyrus and its ability to cross oceanic expanses makes management of this threatened species an international concern. Pteropus vampyrus is an essential seed disperser and pollinator of rain forest trees, many of which are ecologically and economically important. Understanding population dynamics of P vampyrus is thus critical to addressing conservation issues and global health concerns. We used phylogenetic inference and population genetic indices to infer past gene flow between populations of P vampyrus throughout most of the species' range. Population genetic parameters indicate low levels of nucleotide variability with high haplotype diversity across its range, implying a demographic scenario of recent population expansion after a bottleneck. Subspecies were not found to be monophyletic from the genetic data, which may reflect some level of genetic variation on even shallower time scales. The low level of population genetic structure throughout the species range is not necessarily surprising given its high vagility and seasonal migratory behavior. However, it cannot be entirely excluded that these results may reflect historical connectivity or lineage sorting issues rather than more recent persistent gene flow. These findings highlight the need for international cooperation and monitoring to ensure persistence of populations and to create a species management plan that can protect the species throughout its range. Increased genetic sampling is needed to ascertain P vampyrus' commonly used dispersal routes and to assess the possibility of asymmetric gene flow among populations.