Biologists Hatch Comeback for Bald Eagle : Environment: The U.S. national symbol, once down to a relative handful and still endangered across much of their range, grows plentiful in skies over Oregon.

The sky is just starting to lighten along a gravel road in southern Oregon as the mighty birds launch from their night roost in the wooded hills above, heading out in search of breakfast.

Bald eagles--first one, then another, then a pair. They keep coming and coming, the adults with their telltale white head and tail, the juveniles still all dark. By the full light of morning, several hundred have passed overhead.

Armed with binoculars and hot thermoses, bundled in wool hats and gloves, several hundred people scan the sky. Some have flown in from other states, rented cars and motel rooms, spending hundreds of dollars to see this largest winter gathering of bald eagles in the contiguous 48 states. This year they total more than 1,000 birds.

“I’ve counted 79 so far,” one woman says excitedly.

The U.S. national symbol, once down to a relative handful and still endangered across much of its range, is making a comeback.

“During recent years, bald eagle recovery is mostly a success story,” says Ralph Opp, a biologist with the Oregon Department of Fish and Wildlife and the man most responsible for preserving eagle habitat hereabouts. “The numbers continue to increase.”

But as spectacular as they are, the bald eagles are part of a bigger environmental story in the Klamath Basin, which straddles the Oregon-California border and includes six national wildlife refuges. It is a perfect example of ecosystem complexity, involving several endangered species, the impact of human activities on wetlands and the painstaking efforts necessary to preserve that ecosystem and the bald eagle along with it.

Before pioneers started arriving in the middle of the 19th Century, the basin had 185,000 acres of wetlands (mostly shallow lakes and extensive marshes) that were home to hundreds of species of wildlife and attracted more than 6 million waterfowl each year to this stopping point along the Pacific Flyway.

“Cattle were first brought to the valley in 1853, and things began to change rapidly,” says Brian Woodbridge, a wildlife biologist at the Klamath National Forest. “Natural grassland was replaced, and most of the wetlands were drained and cultivated.”

But by 1930, much of the farmland was depleted and abandoned, he says, and desertification had begun. Naturally, this had an effect on wildlife and its habitat.

Total natural wetlands have been reduced by 75%, and the peak concentration of migrating waterfowl--while still one of the largest in the country--has dropped to one-sixth its historic figure. (A U.S. Fish and Wildlife survey early in February totaled 333,750 waterfowl, including 25,105 tundra swan.)

The 47,600-acre Lower Klamath National Wildlife Refuge, the nation’s first waterfowl preserve, was established by President Theodore Roosevelt in 1908. From then to 1978, five more wildlife refuges were established here. The latest is at Bear Valley, mostly old-growth timber and one of five eagle roosts in the basin.

Building up the Klamath Basin refuges has been a long and costly process. During the coming fiscal year, for example, environmental groups hope to see 200 acres added, which could cost $2 million.

Managing the area for wildlife habitat and agriculture also requires great effort. Because the natural water flow was disrupted for farming and grazing years ago, 20,000 acres here must be flooded and drained every year to maintain ideal conditions for waterfowl. This involves pumping 4 billion cubic feet of water from Tule Lake to the Lower Klamath National Wildlife Refuge through an extensive network of drains and canals.

While bald eagles do not nest in the southern part of the basin, this time of year they can be spotted by the dozens along the levies feasting on water birds that have succumbed to disease or in the fields, where a smorgasbord of mice, ground squirrels and voles have fled to high ground during flooding. Occasionally they grapple in aerial combat with hawks and other eagles over territorial rights.

This year, bird enthusiasts added a special treat to their wildlife checklists: a whooper swan that normally migrates from above the Arctic Circle to India and Africa. This bird mistakenly joined a flock of tundra swans, who come here by the thousands every year. People have traveled from as far away as Florida just to see this single bird.

While most of the eagles here for the winter nest as far away as the Northwest Territories of Canada (many coming by way of Glacier National Park in Montana), some make the northern part of the basin their home for breeding. The future of these birds--perhaps four dozen pairs--is closely tied to the management and preservation of the basin ecosystem.

Like the wetlands in the southern basin, Upper Klamath Lake has been affected by human activity. This includes logging, farming and ranching.

Ecologist Jacob Kann, who works for the Klamath Indian tribe out of Chiloquin, Ore., says the cumulative effect of such activity has been an unnatural level of blooming algae in the lake, which in turn reduces dissolved oxygen and raises the relative acidity past the level that fish can tolerate.

In 1988, two species of sucker (the Lost River and short-nosed) were officially listed as endangered by the U.S. Fish and Wildlife Service. Both fish were an important food source for the eagles that nest and raise their young here.

The Bureau of Reclamation is trying to keep enough fresh water in the lake to protect the endangered fish; environmental groups have gone to court to assure that level. But reducing the outflow for irrigation could cost jobs and regional income, according to a new study by economists at UC Berkeley.

In the worst case, the irrigation reduction could cost 3,116 jobs in the farm-labor, farm-related and service-business sectors, with a lost income of $105 million a year, according to the study. Low snowpacks and continuing drought add to the problem.

Some people have suggested maintaining the sucker population through a hatchery program. But, ecologist Kann says, “hatchery fish are not the answer because the habitat is really not there. . . .

“The real problem is overall ecosystem health,” he told a recent conference of scientists, conservationists and bird enthusiasts focusing on the bald eagle.

“The suckers are just an indication that the overall system is out of whack,” he says. “If we protect the ecosystem and habitat, we can protect the species.”

That concern and approach is shared by environmentalists who see the northern spotted owl as a key “indicator species” for protection of old-growth forests.

Such forests are part of the bald eagle story here as well.

West of Upper Klamath Lake in the Winema National Forest, 19,000 acres are designated as an eagle habitat area. For decades, fire suppression meant that white fir trees were able to crowd out the larger Douglas fir and Ponderosa pine, in which eagles build nests that can be up to 10 feet wide and two tons.

Since 1981, the Forest Service has had a habitat management plan that includes commercial thinning and prescribed burns to leave the more fire-resistant Douglas fir and Ponderosa pine standing.

“This favors the larger trees, and it favors the nesting habitat we need,” Forest Service wildlife biologist Brent Frazier says.

In 1980 there were just 15 nesting pairs of bald eagles in this forest. They are increasing by about a pair a year.

“That’s pretty impressive,” Frazier says. “Whether it’ll be successful over time we don’t know, but we have high hopes.”