WASHINGTON -- Guam's tropical forests are silent. The rattling, screeching, and cawing of the island's native birds have been erased by the brown tree snake, a devastating predator accidentally introduced to the island shortly after World War II.
Today, just as US government biologists hope to reintroduce endangered birds, a new threat to the nearly extinct species is looming: A major expansion of US military facilities on Guam is expected to sharply reduce wildlife habitat.
The future of birds on Guam might provide a telling first test of new US policy, proposed by the Bush administration and approved by Congress last year, which exempts military facilities from the ''critical habitat" provisions of the Endangered Species Act. These provisions required the military to consult with the US Fish and Wildlife Service to determine if any of its actions would harm species such as the birds of Guam.
Caught in the tug of war are the tropical forests on Andersen Air Force Base. The Fish and Wildlife Service says they are essential for the conservation of the endangered Micronesian kingfisher, the Mariana crow, and Mariana fruit bat.
Fish and Wildlife initially proposed designating 24,803 acres of Guam's forests as ''critical habitat" for the birds. After Congress gave the military the exemption from critical habitat, the agency slashed its proposal to a mere 376 acres off the base.
It is not clear how much of the forest would be cut down for the base expansion, but the vast majority of suitable habitat on the island is on base land.
The Air Force says it wants to develop the land to ensure its military readiness in the region. Guam, an unincorporated territory of the United States, is a major air and naval staging ground in the Pacific.
No blueprint of the military's plans for Andersen is available publicly. But Colonel Steve Wolborsky, the vice commander of the 36th Air Expeditionary Wing, said the Air Force expected to spend $1 billion to $2 billion to develop Andersen over the next several years, according to American Forces Press Services.
Gordon Rodda, a US Geological Survey biologist who was on Guam in November, said he was told to expect that most of the forest would be cut down for the development. He said the message was, ''Don't think buildings, think city." Rodda and several other biologists took the unusual step of raising alarms about the effect on Guam's birds of the military's exemption from Endangered Species Act provisions.
If Andersen Air Force Base grows as planned, the result will be ''the fastest extinction I have witnessed in my life," said Susan Haig, a biologist for the US Geological Survey who has worked on Guam bird recovery since 1987.
Some policy officials at Fish and Wildlife said that they hoped the military would continue to protect the species.
''Expansion of Andersen is not necessarily mutually exclusive with implementing recovery for these species," said Gina Shultz, acting field supervisor of Fish and Wildlife's Pacific island office. ''But I'm working in a vacuum here, I have no idea where they're expanding [or] how much."
When the Bush administration advocated exempting the military from the critical habitat provisions of the Endangered Species Act, it contended that the military could be trusted to act as a good steward of the environment.
The Guam birds' story ''is symbolic of why environmentalists fight over regulations and sometimes are suspicious of vague sets of promises and guidelines," said John Kostyak, senior counsel for the National Wildlife Federation, a national environmental group.
The Fish and Wildlife agency said the future of the species would hinge on the military's commitment to them as detailed in its Integrated Natural Resources Management Plan. The document included a project, 14 years in the works, to build a snake barrier around a 60-acre area on the base for the birds' benefit.
Brown tree snakes have no natural predators on the island and their numbers have grown to thousands per square mile. Barriers are one of the few ways to manage the population and are considered essential to creating safe habitat for other species.
But in November, government biologists were told that the military was canceling the snake barrier, according to Earl Campbell, the Fish and Wildlife Services Pacific coordinator for invasive species. Some government biologists fear that canceling the snake barrier project was the first tangible sign that the military's plans would imperil efforts to protect the endangered species.
''From my perspective it looks like they reneged on that plan, which leaves no protection for any of the wildlife on Andersen," Haig said. Technical Sergeant Jeffrey Capenos, the base's spokesman, said the fears were premature. He said it was too early to say how much forest would be cut down or how the rare species would be treated as the base expanded.