Managing the Brown Treesnake Headache: Assessment of the Aerial Acetaminophen Bait Drop on Guam

9/22/2016

Managing the Brown Treesnake Headache: Assessment of the Aerial Acetaminophen Bait Drop on Guam

SERDP and ESTCP have launched a webinar series to promote the transfer of innovative, cost-effective and sustainable solutions developed through projects funded in five program areas. The webinar series targets Department of Defense and Department of Energy practitioners, the regulatory community and environmental researchers with the goal of providing cutting edge and practical information that is easily accessible at no cost.

Presented September 22, 2016- Presentation Slides

Abstract

“Managing the Brown Treesnake Headache: Assessment of the Aerial Acetaminophen Bait Drop on Guam” by Dr. Brian S. Dorr

The brown treesnake (Boiga irregularis) was introduced to Guam shortly after World War II and has caused serious ecological damage since including the extirpation of all but two of the 12 native forest birds. An ESTCP-funded project demonstrated an aerial control method deploying dead neonatal mice baits treated with acetaminophen, which is toxic to the snakes, to reduce snake populations in forested sites on Guam. The 16-month demonstration was conducted on three 55-hectare sites (one control and 2 treated sites) on DoD lands on Guam. Snake and rodent numbers were monitored on randomly selected transects on each site every 2 weeks (n = 6,756 bait checks) and 3 months (n = 2,777 trap nights), respectively. Treated mice were individually attached to four-foot-long paper flag streamers and deployed by hand from helicopters. The toxicant baits (dead mice containing 80 mg acetaminophen) were applied in the forest canopy at 36/ha during 7 and 8 drops on the two treated sites, respectively (n = 29,700 baits). The demonstration results were very promising. Significant reductions (p< 0.05) in snake abundance pre- and post- toxicant bait drops were recorded within and between drop sites and the control site with no increase in rodent numbers over the duration of the study. Within drop sites, 83% of recovered snakes were positive for acetaminophen residue (N=6), while no snakes outside of study sites tested positive (n=8).

This demonstration resulted in a significant and sustained reduction in the indices of snake numbers at the treated sites. The aerial application of acetaminophen treated baits can aid DoD interdiction efforts, control snake populations and assist in wildlife restoration efforts. The success of this demonstration project has also laid the groundwork for further advances in the technology using automated bait delivery systems, with the first field test occurring in 2016. For this innovative work, the project team received the 2015 ESTCP Project-of-the-Year Award for Resource Conservation and Climate Change.

Speaker Biographies

Dr. Brian S. Dorr is a Research Wildlife Biologist with the U.S. Department of Agriculture, Wildlife Services, National Wildlife Research Center, adjunct faculty with Mississippi State University, and a Certified Wildlife Biologist (CWB®) with The Wildlife Society. His current research is focused primarily on ecological relationships between avian predators and their environment, and managing invasive species particularly as it relates to wildlife-societal conflict issues. Brian has authored or co-authored 70 peer reviewed, technical papers and book chapters on wildlife and fisheries ecology, management, and wildlife societal conflict issues. He received his B.S. in Business Administration from the University of Arizona in 1990, and his M.Sc. in Wildlife Ecology and Ph.D. in Forest Resources from Mississippi State University in 1997 and 2006, respectively.