USDA keeps snakes off of planes, out of cargo

ANDERSEN AIR FORCE BASE, Guam - -- Last year the United States Department of Agriculture captured 3,200 brown tree snakes here.

According to an article by the U.S. Geological Survey, shortly after World War II, the brown tree snake was accidentally transported from its native range in the South Pacific to Guam, most likely as a stowaway in ship cargo. As a result of abundant prey resources on Guam and the absence of natural predators, brown tree snake populations reached unprecedented numbers.

Since Guam is a major transportation hub in the Pacific, numerous opportunities exist for brown tree snakes from Guam to be accidentally introduced to other Pacific islands in the same way they arrived here. Members of the USDA here are dedicated to preventing this.

"The brown tree snake threatens the economy, ecosystem and overall health of a region," said Marc Hall, the supervisory wildlife biologist of USDA on Andersen. "We're here to help make sure this snake doesn't make its way to neighboring islands and cause the same problems it has here."

This mission is accomplished in three ways: traps are set up to capture brown tree snakes; canine inspections are performed using Jack Russell terriers specifically trained to sniff out the snakes; and spotlighting, which is the process of hand-capturing snakes at night, is carried out two nights a week.

"We have 1,400 snake traps in operation in areas such as the flightline, the munitions storage areas and base housing," said Kan Dhillon, USDA wildlife biologist. "The traps have one-way entrances on both ends of a cylinder. We place a mouse inside a self contained section of the trap along with food and a water source. The snake sees, and smells the mouse and is lured in, but because of the divide, the mouse is completely safe and doesn't get eaten by the snake."

Team Andersen has also taken the offensive. Brown tree snake population control and elimination measures have been developed and subsequently employed throughout the base.

"There are on-going research projects supported by the Air Force that are dedicated to finding ways to attract, lure, and capture brown tree snakes more effectively," Mr. Hall said.

Research has shown that a 40 mg dose of acetaminophen, the primary ingredient in Tylenol, is lethal to virtually any size of brown tree snake.

"Currently, the most effective way to deliver that toxicant to a snake is through a tiny neonatal mouse," Mr. Dhillon said. "We have a way to kill the snake, but we just need to perfect a delivery system that works on a landscape scale."

Some may wonder why government resources are being used to control and eliminate a pest population on Guam, particularly when most have never even seen a brown tree snake.

"As you may or may not know, the brown tree snake is responsible for the extinction of nine of 12 forest birds on Guam," explained Mr. Hall. "Research is showing that the loss of the birds may be impacting the ability of the natural ecosystem to sustain itself."

Before the snakes arrived, Guam's ecosystem was very different. Numerous birds could be seen and heard when walking through the northern limestone forests. Without the birds to disperse seeds and the fact that nonnative pigs and deer tear up the ground and eat sapling plants, the native limestone forest has been severely degraded and will require extensive help in order to recover.

"It is important that people who may come in contact with the brown tree snake, especially at points of exit and other high-risk sites, understand the scope of this problem and how to identify the snake so proper action can be taken," Mr. Hall said.

For more information, contact the USDA at 366-3822.