The Bald Eagle Rebounds
Endangered US national symbol shows signs of recovery in complex Oregon ecosystem
| BEAR VALLEY NWR, ORE.
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 trademark white head and tail, the juveniles still all dark - until 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 humans scan the skies. 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, a number that this year totals more than 1,000 birds.
"I've counted 79 so far," says one woman excitedly.
The United States 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 mid-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," explains 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, he adds, much of the farmland was depleted and abandoned, and desertification had begun. Naturally, this had an effect on wildlife and its habitat.
Total natural wetlands had been reduced by 75 percent, and the peak concentration of migrating waterfowl - while still one of the largest in the country - had dropped to one-sixth its historic figure. (A US 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 (NWR), the nation's first waterfowl refuge, was established by President Theodore Roosevelt in 1908. Between then and 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 who have succumbed to disease or in the fields where a smorgasbord of mice, ground squirrels, and voles have fled to the high ground when the flooding occurs. Occasionally they grapple in aerial combat with hawks and other eagles over territorial rights.
This year bird enthusiasts were able to add 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 up with 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 purposes. 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 part of the 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., explains that 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 pH level (relative acidity) past the level fish can tolerate. In 1988, two species of sucker (the Lost River and short-nosed) were officially listed as endangered by the US Fish and Wildlife Service. Both fish were an important food source for the eagles who
nest and raise their young here.
The US Bureau of Reclamation is trying to keep enough fresh water in the lake to protect the endangered fish, and environmental groups have gone to court to make sure this happens. But reducing the outflow for irrigation could cost jobs and regional income, according to a new study by economists at the University of California at Berkeley. In the worst case, this could total 3,116 jobs in farm labor, farm-related, and service-business jobs and a lost income of $105 million a year, according to the study.
Low snow packs and continuing drought add to the problem.
Some people have suggested maintaining the sucker population through a hatchery program. But, says Mr. Kann, "Hatchery fish are not the answer because the habitat is really not there to put these guys."
"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. If we protect the ecosystem and habitat, we can protect the species."
That concern and approach is shared by those environmentalists who see the controversial 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 efforts 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 as wide as 10 feet and weigh two tons.
Since 1981, the US 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," says Forest Service wildlife biologist Brent Frazier.
In 1980 there were just 15 nesting pairs of bald eagles in this forest. They're now increasing by about a pair a year. "That's pretty impressive," says Mr. Frazier. "Whether it'll be successful over time we don't know, but we have high hopes."