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USDA To Mice Bomb Guam In Effort To Reduce Invasive Brown Tree Snake Population

Boiga irregularis first arrived on Guam during World War II.

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The U.S. Department of Agriculture’s Wildlife Service plans to mice bomb the island of Guam with acetaminophen-laced dead feeders in an effort to reduce the population of invasive brown tree snakes that have overtaken the U.S. territory. The agriculture department started conducting tests to determine if the mice drop would be effective in 2010 and believe that such a drop would have little impact on the other animals that inhabit the forests, such as birds, since most of them have been wiped out by the snakes already.

The planned drop is scheduled for April or May of this year. It will be near Andersen Air Force Base, which is on a peninsula that is heavily forested. The mice, to be dropped by hand, will be outfitted with a device that is designed to catch in the tree branches where the snakes are located and to prevent them from reaching the forest floor. The mice will also be implanted with a tracking device to further study the success of the drop.


The brown tree snake is an invasive species on Guam and is said to have made its way there by hitching a ride on an airplane or stowing away on a boat during the time of World War II. It is native to northern Australia, New Guinea, and the Solomon Islands. It averages two to four feet in length with the largest specimen captured on Guam measuring 10 feet. It has wreaked havoc on the local wildlife, and has decimated 10 of 12 native bird species to the point of extinction on Guam. With these birds removed from the ecosystem, the island’s spider populations have gone largely unchecked, according to a study published in the journal PLoS One. The snakes also cause blackouts on the island by climbing onto electric lines; disrupting power several times a week and occasionally causing island wide blackouts. According to the US Geological Survey, more than 1,600 brown tree snake-caused power outages occurred between 1978-1998.

“We are taking this to a new phase,” Daniel Vice, assistant state director of USDA’s Wildlife Services in Hawaii, Guam, and the Pacific Islands told the Associated Press. “There really is no other place in the world with a snake problem like Guam.”

To read more about the impact the brown tree snake has had on Guam’s bird populations, click here.


John B. Virata keeps a ball python, two corn snakes, a king snake, and two leopard geckos. His first snake, a California kingsnake, was purchased at the Pet Place in Westminster, CA for $5. Follow him on Twitter @johnvirata