Yearslong efforts to control the population of brown tree snakes in a protected habitat behind the military fence have been yielding results, according to a Joint Region Marianas report.
Since 2011, 135 acres of jungle on Andersen Air Force Base have been designated as a Habitat Management Unit for ecological study, the report states. The fenced-off area is designed to keep out invasive snakes, pigs and deer. A large, protruding bump around the fence line was specifically installed to snake-proof the enclosure.
Environmental experts managing the area said it’s harder and harder to find snakes within the unit and signs point to a dwindling population, according to the report.
Every 90 days, a UH-6 helicopter fitted with an automated snake bait dispenser undertakes a multiday bait drop over the area. The bait is laced with Tylenol, which is toxic to the snakes and other reptiles.
About 46,200 baits have been dropped into the habitat over the past five years, according to the report.
The habitat has been a “measuring stick” for the ecological health of the island as the snake population within can be closely observed for signs of environmental impact.
Brown tree snakes have disturbed the ecological balance of Guam since the 1950s, when the species arrived stowed away on ships.
“They are opportunistic feeders,” said Megan Parker, a natural resources specialist with Joint Region Marianas. “Since they were introduced, there has been a cascading effect. They eat the birds; fewer birds means more pests and diseases and then there are no native birds to spread native seeds – that’s another big impact.”
The Department of Defense has been working for years with the Guam Department of Agriculture and U.S. Fish and Wildlife Service to try to mitigate the snake population and prevent its spread.
