The invasive brown treesnake (BTS) was introduced to Guam nearly 70 years ago, likely through post-World War II cargo shipments. Since its introduction, the snake has colonized the entire island, at densities of up to 33 snakes per acre.
These venomous snakes have caused the extinction of most of Guam's native birds, bats, and lizards; and they feed on young poultry and other small livestock, and threaten human health and safety. They also cause power outages throughout Guam, resulting in millions of dollars in structural damages and lost revenue.
Federal, state, and territorial governments are committed to preventing the spread of BTS from Guam and mitigating their day-to-day impacts on the island. The unintentional movement of snakes as a result of shipping or travel is a very real danger to all islands in the western Pacific basin and sections of the U.S. mainland. The economic costs of the potential BTS colonization to the Hawaiian Islands alone are estimated to be as high as $2 billion annually.
To prevent the spread of BTS and reduce the snake's impacts on Guam, the USDA Wildlife Services program has partnered with the Government of Guam's Department of Agriculture, the U.S. Department of Defense, Office of Insular Affairs, and the U.S. Fish and Wildlife Service. The prevention program uses a variety of control tools and strategies, including the use of traps, fumigants, hand capture, snake-detector dogs, public education, and an oral toxicant. In 2003, the toxicant acetaminophen was granted a registration by the U.S. Environmental Protection Agency based on research conducted by National Wildlife Research Center (NWRC) scientists. The toxicant is currently used in bait stations around ports, the airport, and other easily accessible areas of the island.
The prevention program uses a variety of control tools and strategies, including the use of traps, fumigants, hand capture, snake-detector dogs, public education, and an oral toxicant.
In 2009, the NWRC and Applied Design Corporation (ADC) entered into a series of cooperative agreements to design a bait cartridge, automated manufacturing system, and aerial bait delivery system for the distribution of acetaminophen to BTS in remote and inaccessible areas on Guam. The NWRC provided information on BTS ecology and behavior, and guidance regarding EPA's pesticide regulation and early prototype concepts. Working together, NWRC scientists and experts at ADC designed a biodegradable bait cartridge and delivery system that can disperse a bait cartridge every 15 meters (4 bait cartridges/second at a flight speed of 125 knots) via helicopter or fixed wing aircraft.
In 2014, ADC and the NWRC jointly filed for a U.S. patent for the bait cartridge; and ADC plans to file two additional patents related to its automated bait delivery system and bait manufacturing process. ADC plans to commercialize this technology for use in wildlife damage management. The new technology provides large-scale control of BTS populations on Guam, and invasive species management worldwide.