ANDERSEN AIR FORCE BASE, Guam » Dead mice laced with painkillers are about to rain down on Guam’s jungle canopy. They are scientists’ prescription for a headache that has caused the tiny U.S. territory misery for more than 60 years: the brown tree snake.
Most of Guam’s native bird species are extinct because of the snake, which reached the island’s thick jungles by hitching rides from the South Pacific on U.S. military ships shortly after World War II. There may be 2 million of the reptiles on Guam now, decimating wildlife, biting residents and even knocking out electricity by slithering onto power lines.
More than 3,000 miles away, Hawaii environmental officials have long feared a similar invasion — which in their case likely would be a “snakes on a plane” scenario. That would cost the state many vulnerable species and billions of dollars, but the risk will fall if Guam’s air-drop strategy succeeds.
“We are taking this to a new phase,” said Daniel Vice, assistant state director of U.S. Department of Agriculture’s Wildlife Services in Hawaii, Guam, and the Pacific Islands. “There really is no other place in the world with a snake problem like Guam.”
Brown tree snakes are generally a few feet long but can grow to be more than 10 feet in length. Most of Guam’s native birds were defenseless against the nocturnal, tree-based predators, and within a few decades of the reptile’s arrival, nearly all of them were wiped out.
The snakes can also climb power poles and wires, causing blackouts, or slither into homes and bite people, including babies; they use venom on their prey but it is not lethal to humans.
The infestation and the toll it has taken on native wildlife have tarnished Guam’s image as a tourism haven, though the snakes are rarely seen outside their jungle habitat.
The solution to this headache, fittingly enough, is acetaminophen, the active ingredient in painkillers including Tylenol.
The strategy takes advantage of the snake’s two big weaknesses. Unlike most snakes, brown tree snakes are happy to eat prey they didn’t kill themselves, and they are highly vulnerable to acetaminophen, which is harmless to humans.
The upcoming mice drop is targeted to hit snakes near Guam’s sprawling Andersen Air Force Base, which is surrounded by heavy foliage and if compromised would offer the snakes a potential ticket off the island. Using helicopters, the dead neonatal mice will be dropped by hand, one by one.
U.S. government scientists have been perfecting the mice-drop strategy for more than a decade with support from the Department of Defense and the Department of the Interior.
To keep the mice bait from dropping all the way to the ground, where it could be eaten by other animals or attract insects as they rot, researchers have developed a flotation device with streamers designed to catch in the branches of the forest foliage, where the snakes live and feed.
Experts say the impact on other species will be minimal, particularly since the snakes have themselves wiped out the birds that might have been most at risk.
Scientists from the Smithsonian using DNA data sets to outline the evolutionary family tree of the Hawaiian honeycreeper have determined that the 56 species of the native bird evolved from the Eurasian rosefinch.
In another important finding, the researchers linked the timing of the evolution of the honeycreeper to the formation of the four main Hawaiian Islands.
“It was fascinating to be able to tie a biological system to geological formation and allowed us to become the first to offer a full picture of these birds’ adaptive history,” said Helen James, a research zoologist at the Smithsonian’s National Museum of Natural History and an author of a paper on the study.
Fern Duvall, state Forestry and Wildlife Division wildlife biologist, who was not involved with this study but is working with two of the authors of the paper, James and Rob Fleischer, on a similar project with shorebirds, called the findings “dynamic” and “unique.”
Putting the research in context, Duvall noted that many bird experts believed the honeycreepers to be descendants of the house finch of North America. Instead, the researchers say the Eurasian rosefinch from Asia is the mother bird of the species.
As for the evolutionary discoveries, Duvall said it had been theorized that there was a link between the biologic and geologic development of the birds to the islands. The scientific connection made in the study is new, he said.
“For them to show that that is the case is dynamic,” he said Wednesday. “I think it’s an excellent example that birds’ forms are tied to diverse habitat types.”
Federal officials have taken two dozen endangered songbirds from Nihoa in the Northwestern Hawaiian Islands and moved them to Laysan 650 miles north in the hope they will establish a new population there and prevent the extinction of the species.
Nihoa Millerbirds are currently only found on Nihoa, where there is a population numbering between 500 and 700. A related subspecies once lived on Laysan but went extinct there after introduced rabbits destroyed the island’s vegetation.
Officials hope establishing a new population will reduce the chances a hurricane or disease outbreak at Nihoa will wipe out the species.
The U.S. Fish and Wildlife Service and its public and private partners moved the birds earlier this month. Officials said Monday the project took five years to plan and cost about $850,000.
Six birds found dead recently in Southern California’s Tehachapi Mountains were majestic golden eagles. But some bird watchers say that in an area where dozens of wind turbines slice the air they were also sitting ducks.
The U.S. Fish and Wildlife Service is investigating to determine what killed the big raptors, and declined to divulge the conditions of the remains. But the likely cause of death is no mystery to wildlife biologists who say they were probably clipped by the blades of some of the 80 wind turbines at the three-year-old Pine Tree Wind Farm Project, operated by the Los Angeles Department of Water and Power.
As the Obama administration pushes to develop enough wind power to provide 20 percent of America’s energy by 2030, some bird advocates worry that the grim discovery of the eagles this month will be a far more common occurrence.
Windmills kill nearly half a million birds a year, according to a Fish and Wildlife estimate. The American Bird Conservancy projected that the number could more than double in 20 years if the administration realizes its goal for wind power.
The federal government is accepting public comment on a plan by Kauai Lagoons to protect endangered and threatened species from harm while it builds nearly 800 new residential units and a new golf clubhouse on its resort property in Lihue.
The U.S. Fish and Wildlife Service said Tuesday it will accept comments through Aug. 26. The plan is available at the agency’s website for the Pacific Islands and through its Honolulu office.
Some of the development will replace structures damaged by Hurricane Iniki in 1992.
Part of the plan calls for the resort to help the state move endangered nene geese from the property to Maui and the Big Island. The state is moving the birds to take them away from the path of airplanes using Lihue airport.