Data from: Testing for multiple invasion routes and source populations for the invasive brown treesnake (Boiga irregularis) on Guam: implications for pest management

The brown treesnake (Boiga irregularis) population on the Pacific island
of Guam has reached iconic status as one of the most destructive invasive
species of modern times, yet no published works have used genetic data to
identify a source population. We used DNA sequence data from multiple
genetic markers and coalescent-based phylogenetic methods to place the
Guam population within the broader phylogeographic context of B.
irregularis across its native range and tested whether patterns of genetic
variation on the island are consistent with one or multiple introductions
from different source populations. We also modeled a series of demographic
scenarios that differed in the effective size and duration of a population
bottleneck immediately following the invasion on Guam, and measured the
fit of these simulations to the observed data using approximate Bayesian
computation. Our results exclude the possibility of serial introductions
from different source populations, and instead verify a single origin from
the Admiralty Archipelago off the north coast of Papua New Guinea. This
finding is consistent with the hypothesis that B. irregularis was
accidentally transported to Guam during military relocation efforts at the
end of World War II. Demographic model comparisons suggest that multiple
snakes were transported to Guam from the source locality, but that fewer
than 10 individuals could be responsible for establishing the population.
Our results also provide evidence that low genetic diversity stemming from
the founder event has not been a hindrance to the ecological success of B.
irregularis on Guam, and at the same time offers a unique ‘genetic
opening’ to manage snake density using classical biological approaches.