A Fuzzy Airstrike on the Brown Tree Snakes (Boiga irregularis) of Guam

This slideshow requires JavaScript.

Brown tree snakes (Boiga irregularis) are an invasive species introduced to the island of Guam accidently through cargo ships in the late 1940’s. Today their population has reached unprecedented numbers, devastating the majority of birds, lizards, bats, rats, and small rodents found on the island. It is now believed this snake is responsible for the extinction of twelve native bird species.

The abundance of prey and lack of predators have caused the snakes to grow to larger than their original  1 to 2 metres (3.3 to 6.6 feet) as found in native species on  Australia, Indonesia and Papua New Guinea. The longest on record found in Guam measured 3 metres (9.8 feet) in length.

The snakes are costing Western Pacific industries millions in annual repair costs and lost productivity as power failures caused by the snakes who wriggle into electric substations, shut down operations at an average rate of 80 times a year.

Many U.S. establishments in the Western Pacific are trying a number of ways to control the snake population including the use of snake traps, snake-sniffing dogs and snake-hunting inspectors. However, the best result so far has been using combination of mice laced with acetaminophen.

Brown tree snakes are uniquely sensitive to acetaminophen, an active ingredient in over-the-counter painkillers such as TYLENOL®. It only takes 80mg to kill a snake, whereas pigs or other similarly sized animals would have to eat about 500mg to get a lethal dose. To put this into perspective the size of a TYLENOL® Regular Strength Tablet contains 325 mg of acetaminophen.

But how would one disperse mice over large sections of the infested island? And the answer is:floating mice down from the sky. 2,000 mice at a time are wafted down on tiny cardboard parachutes into targeted areas.

 “Helicopters make low-altitude flights over forested areas, dropping their furry bundles on a timed sequence. Each mouse is laced with the deadly micro-dose of acetaminophen and strung up to two pieces of cardboard and green tissue paper.” M. Alex Johnson, Staff Writer, NBC News

“The process is quite simple,” states Dan Vice, the Agriculture Department’s assistant supervisory wildlife biologist for Guam. “The cardboard is heavier than the tissue paper and opens up in an inverted horseshoe. It then floats down and ultimately hangs up in the forest canopy. Once it’s hung in the forest canopy, snakes have an opportunity to consume the bait.”

In addition to the acetaminophen and the parachutes, some of the poison pests come equipped with tiny data-transmitting radios so researchers can check if a direct hit was achieved.

Guam is home to an estimated 2 million of these reptiles, with some areas reaching a density of 13,000 per square mile; a density considered more concentrated than Amazonian rainforests, the government says. Testing new and creative ways to control the Brown tree snake population goes a long way to helping preserve Guam’s ecological diversity.

For original article by By M. Alex Johnson, Staff Writer, NBC News click HERE