An Evolutionary Approach to the Biological Management of Invasive Brown Treesnakes (Boiga irregularis) on Guam
Abstract
The ecological success of invasive brown treesnakes (Boiga irregularis) on Guam is related to a lack of natural population controls in the non-native environment. While certain techniques have successfully reduced the number of snakes entering ports and other critical infrastructure, limited research has explored the prospects for biological control as an additional management tool. We proposed to use the phylogenetic relationships of B. irregularis populations spanning the native species range as an evolutionary map for targeting native populations to survey for parasites. Our rationale was that once parasites could be characterized in native populations representing a range of phylogenetic distances to the Guam snakes, it would be possible to develop a candidate list of parasites for experimental studies on biocontrol efficacy. Our objectives address these endeavors by (1) genetically identifying the source population(s) for introduced Boiga on Guam, (2) providing preliminary phylogenetic data upon which to base decisions for parasite prospecting, (3) testing the longstanding presumption that Guam B. irregularis are parasite free, (4) assessing whether parasites from the source population persist on Guam and (5) providing an initial characterization of metazoan and protozoan parasites in B. irregularis populations within its native range. We used DNA sequence data from five genetic markers and Bayesian modeling to infer a phylogeny for B. irregularis populations occurring over much of the native range. We used these same data to compare indices of genetic diversity in the native and introduced range, as low genetic variation on Guam may indicate a reduced immunological capacity to respond to infection. We harvested parasites from field-captured snakes at two locations, one representing the putative source of the Guam population and one representing mainland New Guinea, and identified parasites to the lowest taxonomic rank possible based on morphology.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 14, 2012
- Accession Number
- ADA600553
Entities
People
- Dustin A. Wood
- James W. Stanford
- Jonathan Q. Richmond
- Robert N. Fisher