60 years after they found their way to the shores of Guam, brown tree snakes have become the island's most pervasive invasive species. Now believed to number in the millions, the unwelcome serpents have decimated the region's wildlife, slithering without having to worry about any natural predator. Faced with this unchecked threat, experts have teamed up with an unlikely ally in the battle against snakes -- scores of parachuting mice laced with a lethal payload.
Authorities from the US Geological Survey believe that the snakes first arrived to Guam, a US territory in the west Pacific, hitching a ride by boat or plane during World War II. Since then, the snakes have proliferated on an unimaginable scale by feasting on the island's native bird species, and their population growth left unchecked shows no signs of slowing.
As conventional methods of controlling the snakes have done little to squelch the island's 2 million or so brown tree snakes, conservation officials have begun experimenting with a more creative approach.
From the BBC:
One effort has involved air-dropping mice that have been laced with poison and fitted with parachutes out of helicopters. It provides a deadly dinner for any unsuspecting snakes below.
"Right now we are using acetaminophen (paracetamol). It commonly used as a pain reliever and fever reducer in humans, but it is 100% lethal to all brown tree snakes," explains Dan Vice of the US Department of Agriculture.
If the move seems rooted in desperation, that may be because it is. In the last six decades, brown tree snakes have transformed Guam's island ecosystem, perhaps beyond repair.
"The brown tree snake has had a devastating impact. Ten out of 12 native forest bird species disappeared in 30 years," reports Cheryl Calaustro, of the Department of Agriculture. "The birds here evolved without predators. They were quite naive. And when the snake arrived on Guam it ate eggs, juveniles, adults. Whole generations disappeared."