The marbled murrelet, a threatened sea bird whose rare trait of nesting in old-growth forests made it a factor in logging battles in the U.S. Northwest, is also declining dramatically in Alaska and Canada, where most of the birds live, according to U.S. government review.
The review of existing population surveys by the U.S. Geological Survey was requested by the U.S. Fish and Wildlife Service as the Bush administration considers whether to take the marbled murrelet off the threatened species list in Oregon, Washington and California, where protection for the old-growth trees it nests in have dramatically reduced logging on some national forests.
The first comprehensive look at population surveys in Alaska and British Columbia found an overall decline of about 70 percent over the last 25 years, dropping the estimated population to 270,000 birds in Alaska and 54,000 to 92,000 birds in British Columbia.
The review released Monday found that genetically, the birds divide into three groups: the western tip of the Aleutian Islands of Alaska; the rest of the Aleutians south through British Columbia, Washington, and Oregon into California; and central California.
The bird is not protected in Alaska.
Fish and Wildlife Service spokeswoman Joan Jewett said they had received the USGS report, and were reviewing it.
There is no time set for making a decision on marbled murrelett protection.
USGS sea bird biologist John F. Piatt, lead author of the review, said none of the known human-caused threats to marbled murrelets - loss of nesting trees to logging, getting caught in gillnets, and oil spills - can by themselves explain the dramatic and widespread decline, particularly in Alaska.
"Nobody was really expecting that kind of change," Piatt said from Port Townsend, Washington. "Natural influences may be more important than human-caused," changes.
Even areas like Alaska's Glacier Bay, where there has been no logging, saw dramatic declines, raising the likelihood that something larger was a major factor, he said.
That could be changes in the ocean climate, such as a 1977 shift in the North Pacific that altered the availability of fish and zooplankton the birds feed on, and an increase in predators such as ravens and bald eagles in the forests where the bird nests, which could be related to logging and urban development.
The marbled murrelet is rare among sea birds, because it flies up to 50 miles (80 kilometers) inland to lay an egg on the branch of an old-growth fir or hemlock, rather than nest on the ground on an offshore island. That makes it particularly vulnerable to predators.
The Bush administration decision to review threatened species status for the marbled murrelet was triggered by a lawsuit brought by the timber industry, which argued that with nearly 1 million birds living off British Columbia and Alaska, there was no need to protect it in the Northwest.
This latest population review revised the population estimate for Alaska and Canada from more than 1 million to about 350,000.
"We still think the species should have never been listed," said Chris West, vice president of the American Forest Resource council. "Even though there's this estimate there has been a 70 percent decline, we are still taking about hundreds of thousands if not millions of individual birds. How can you list a population that has got that many members in it, especially when it covers such a vast area?"
Susan Ash, conservation director of Portland Audubon, said a recent proposal from Fish and Wildlife to drastically cut protections for nesting trees could lead to the bird's extinction in the Northwest, the AP reports.
Noah Greenwald of the Center for Biological Diversity said the review refuted Fish and Wildlife's argument that protections for the marbled murrelet in Canada were comparable to those in the United States by noting that nearly half the nesting habitat in British Columbia has been logged.
An earlier status review of the marbled murrelet done for Fish and Wildlife concluded the bird was likely to disappear from Washington, Oregon and Northern California by the end of this century, particularly if more nesting trees were cut down.