[ed. I hadn't heard about this eradication program until this morning. Apparently, it's still going strong with a fourth drop just recently completed.]
In the U.S. government-funded project, tablets of concentrated acetaminophen, the active ingredient in Tylenol, are placed in dead thumb-size mice, which are then used as bait for brown tree snakes.In humans, acetaminophen helps soothe aches, pains, and fevers. But when ingested by brown tree snakes, the drug disrupts the oxygen-carrying ability of the snakes' hemoglobin blood proteins.
"They go into a coma, and then death," said Peter Savarie, a researcher with the U.S. Department of Agriculture (USDA) Wildlife Services, which has been developing the technique since 1995 through grants from the U.S. Departments of Defense and Interior.
Only about 80 milligrams of acetaminophen—equal to a child's dose of Tylenol—are needed to kill an adult brown tree snake. Once ingested via a dead mouse, it typically takes about 60 hours for the drug to kill a snake.
"There are very few snakes that will consume something that they haven't killed themselves," added Dan Vice, assistant state director of USDA Wildlife Services in Hawaii, Guam, and the Pacific Islands.
But brown tree snakes will scavenge as well as hunt, he said, and that's the "chink in the brown tree snake's armor." (...)
By contrast, this latest approach aims to take the fight into Guam's jungles, where most of the invasive snakes reside.
A popular misconception about Guam, Vice said, is that the entire island is overrun by brown tree snakes. In reality, most of the snakes are concentrated in the island's jungles, where it is difficult for humans to reach.
"You don't walk out the front door and bump into a snake every morning," Vice said. (...)
Before the laced mice are airdropped, they are attached to "flotation devices" that each consist of two pieces of cardboard joined by a 4-foot-long (1.2-meter-long) paper streamer.
The flotation device was designed to get the bait stuck in upper tree branches, where the brown tree snakes reside, instead of falling to the jungle floor, where the drug-laden mice might inadvertently get eaten by nontarget species, such as monitor lizards.
by Ker Than, National Geographic | Read more:
Image: Vice
