David Klingbiel disappears into a thick patch of hemlock saplings on a timbered slope in Washington’s Olympic National Forest. A few minutes later he calls out the circumference of a large Douglas-fir, and his crew member, Holly Bradbury, records it on a plot card. The two then traipse through the brush measuring the tree’s crown diameter, percent of canopy cover and the number and location of “platforms” formed by swellings, forks or mistletoe brooms in its limbs.

Canopy platforms are crucial nesting spots for marbled murrelets, the most secretive—and threatened—seabird in the Pacific Northwest. A murrelet pair is known to use this stand for nesting. Klingbiel and his crew are gathering data from eight half-acre plots scattered throughout the stand to get an accurate description of the forest type the pair chose for its nest. Crews like theirs are surveying similar occupied forest stands along the Pacific slope from the Canadian border to Northern California. They are part of a massive effort to determine the population status and habitat needs of these elusive old-growth nesters. But a decade after the U.S. Fish and Wildlife Service reluctantly listed the bird as threatened under the Endangered Species Act, it’s impossible to tell if their numbers have begun to rebound.

Of the old-growth-dependent species that come under the protection of President Clinton’s 1994 Northwest Forest Plan, marbled murrelets are far and away the most difficult to track. For one thing, they spend most of their lives at sea. When they enter the forest to nest, they come and go in the dim light of dawn and dusk to avoid attracting predators. They nest high in the old-growth canopy, and chicks stay quiet at the nests.

For decades their nesting strategy remained a mystery. It wasn’t until 1974 that a tree surgeon discovered the first nest, where a small downy seabird huddled on a mossy limb high in a Douglas-fir in California’s Big Basin Redwoods State Park. Since then, some 500 nests have been discovered, many in the past few years with the help of radio transmitters. Nearly all were on mossy platforms in the canopies of large old trees.

Murrelet nests are hardly nests at all, usually just depressions in thick moss blanketing limbs or mistletoe brooms. Murrelets choose nesting sites in low-elevation forests within fifty miles of the coast. And they are particular. Nest trees are usually a minimum of thirty-two inches in diameter. Nests are close to the trunk and are often protected by overhanging foliage. It takes between 200 and 250 years for these conditions to develop in Northwest forests (though mistletoe platforms have been used on trees as young as sixty). The older forests along the coastal areas of California, Oregon and Washington were the first to be logged over the past century.

Before that time, an estimated 19 million acres of ancient forest covered Washington, Oregon and Northern California. By 1992, when the marbled murrelet was listed as threatened, less than 10 percent remained. As forests disappeared, so did murrelets. The species is absent from coastal waters for 100 miles between Washington’s Olympic Peninsula and Tillamook County, Oregon, and for 300 miles between northern and central California. Both areas are dominated by heavily logged corporate forestlands, an absence of federal forests and a paucity of old growth.

In 1994, President Clinton’s Northwest Forest Plan established guidelines for protecting habitats for old-growth- and mature-forest-dependent wildlife on U.S. Forest Service and Bureau of Land Management lands. The plan protects 89 percent of murrelet nesting habitat on federal lands as well as habitats within half-mile circles of known nesting sites, but it offers no protections on private lands. To monitor the plan’s effectiveness, Forest Service researchers conduct extensive population surveys of the birds in the only environment where they can be easily seen and counted, at sea.

Around the time of the forest plan’s implementation, a Forest Service study of murrelets estimated the population in Washington, Oregon and California to be between 18,000 and 19,000. Fifty-thousand murrelets were estimated for British Columbia and 220,000 for Alaska. Since then, hundreds of researchers have been trying to get a handle on the status of this species. A flotilla of research vessels surveys the birds during nesting seasons from San Francisco Bay to Puget Sound.

Most of the research is conducted by Forest Service survey crews, some by state biologists and some by independent researchers. The work is critical to determine whether measures outlined in the forest plan are adequate to maintain and restore the species. Unfortunately, that information has proved extremely difficult to pin down.

C. J. Ralph, a Forest Service researcher with the Redwood Sciences Laboratory in Arcata, California, has coordinated at-sea surveys along the California and southern Oregon coasts since the late 1980s. He sees population numbers as having held steady, “with no severe declines or heartening increases.” Numbers showed a decline off the southern Humboldt coast during the late 1990s, but have increased over the past couple of years. The problem, says Ralph, is that the range of variability of the species makes it difficult to count. “You can go out one day on a stretch of coast and find no birds, and on the next day find 100,” he says. Population estimates may also be skewed by nonbreeding birds from the north coming south during winter to feed and staying into the breeding season. The next year they may be gone.

Compounding the problem, government scientists heading the monitoring effort have changed offshore survey methods over the past two years, and researchers are unable to correlate new numbers with their previous ten years of data.

Patrick Jodice oversees marbled murrelet monitoring under the Northwest Forest Plan for the Fish and Wildlife Service. He says the new census design is critical for accessing population trends throughout the range over time. Under the new protocols, population estimates for the three-state area were 18,000 in 2000 and 21,000 in 2001. But the range of accuracy for both years was between 13,000 and 26,000. Jodice prefers to stick with the later figures. “We have a 95 percent certainty level on these numbers,” he says. “The true population lies within that range.” With more years of data, Jodice and his team will learn what the range of variability is, “then we can look at trends over time.”

The first look at long-term population trends for murrelets will be the ten-year review of the Northwest Forest Plan in 2004. Jodice predicts that he will have a handle on variability by then and a better sense of what the numbers mean. But he adds that ten years of data will give a fuller picture. Under the new survey methods, that won’t be until 2009.

Meanwhile, the Fish and Wildlife Service has approved habitat management plans that allow logging occupied murrelet nest sites on state and private lands in all three states. In California, the Environmental Protection Information Center has filed a sixty-day notice to bring suit against the agency for approving Pacific Lumber Company’s plan to log 10,000 acres of occupied murrelet habitat in its Humboldt County forest holdings. The agreement was part of the 1999 Headwaters Forest deal, in which the government purchased about 7,000 acres of redwoods from the company to preserve as habitat. As part of a federal action, the plan comes under Endangered Species Act review.

The California Department of Fish and Game says logging would impact an estimated 340 murrelets. Cynthia Elkins, program director for the Environmental Protection Information Center, says that amounts to nearly a quarter of the already depressed southern Humboldt population. “This is a critical population in serious decline,” Elkins says. “It’s been impacted by two oil spills in the past five years. And it can’t sustain this level of logging.”

Oil spills, predation, shifts in ocean currents and prey abundance, even longer-term changes like El Ni–o and the Pacific decadal oscillations affect murrelet numbers at sea. Forest management is only part of the picture, but biologists agree that nesting habitat is critical.

Ralph sees court challenges as inevitable. Agencies will be called upon to defend their actions with data showing that plans in place to protect marbled murrelets are working. He says it’s easy to find money to count the birds. It’s much harder to get a commitment to fund statisticians to work up methods that will correlate the past thirteen years of data and determine population and reproductive trends.

“There’s a Rosetta stone out there” Ralph says. “With a serious financial commitment, we could tackle the problem of population size within a year.” He says that would be in the best interest of the species as well as all the agencies involved.

Meanwhile, these small seabirds continue their unlikely commutes up coastal valleys into the deep shade of old forests to nest and feed their chicks. But ten years after coming under the glare of the endangered species spotlight, they’re still incredibly hard to see.