Meeting Abstract
Sex pheromones are potent signals mediating mate choice, and the manipulation of pheromone production in natural populations serves as a powerful management strategy for pest and invasive species. At least one invasive reptile species, the brown tree snake (Boiga irregularis), is known to use skin-based cues for locating and choosing between potential mates, especially in its invasive range on Guam. The components of brown tree snake skin lipids that have pheromonal properties have been described previously, but it is not known if the their lipid profiles are strongly sexually dimorphic or respond to steroidal manipulation. Previous work in another snake species demonstrated that both estrogen implantation and testosterone removal (castration) could induce female pheromone expression in male red-sided garter snakes. It was thus the goal of this study to use estrogen implantation to manipulate putative pheromone expression in male brown tree snakes and determine the effect of implantation on male attractiveness. We implanted male brown tree snakes (n=7) with silastic implants (1 cm) containing estradiol and found that implanted males had significantly altered expression of long-chain methyl ketones, specifically the longer, monunsaturated ketones. This was supported by both general abundance analyses of specific compounds and using MRPP and multidimensional scaling plots. Next, we plan to test the pheromone extracts in bioassays to assess attractiveness of the isolates. If male brown tree snakes can be induced to express female-typical skin lipids that are attractive to other males, it may be possible to generate an attractant that could be used in trapping efforts currently in place on Guam.
