Almost all of Hawai'i's non-migratory native birds are on a new watch list of the United States' most imperiled bird species.

The list, released yesterday by the National Audubon Society and American Bird Conservancy, includes about one-quarter of the more than 700 species that breed in the United States.

The groups cited an array of human activities — habitat loss from urban sprawl and energy development, introduction and invasion of foreign animals and disease, and global warming — as key causes of declines in the populations of 217 kinds of threatened and endangered birds.

Ninety-eight species are regarded at "imminent risk of extinction," Audubon president John Flicker says. "The clock is ticking. Many will not survive unless we act to save them."

The birds' home territories range from tropical forests in Florida and eastern woodlands to the sagebrush deserts of the western states. The most alarming location, however, is Hawai'i. Thirty-nine of the 41 native species that live and breed only on the islands are on the list.

"Hawai'i is way out there, so it's out of sight and therefore out of mind in the continental U.S.," says George Fenwick, head of the conservancy.

Fenwick's group has petitioned the federal government to put two of those birds on the endangered species list, which would give them more protection. Six others are seldom seen and may already be gone, conservancy vice president Mike Parr says.

"They are so fascinating and so little-known, we don't even know if some of them are extinct, and yet (Hawai'i) ... is one of the United States," Parr says. "You expect that in the wilds of New Guinea or the Amazon basin, but not in America."

Those species may still live in remote parts of the islands. Parr says digital recorders are being tested there to try to detect the birds' songs.