Oregon's bald eagle population rebounds
By ERIC MORTENSON
The Oregonian via Associated Press
PORTLAND, Ore. (AP) -- A bald eagle glides low, curving with the meandering sloughs of Oaks Bottom Wildlife Refuge in Southeast Portland.
At the former St. Johns landfill northwest of downtown, workers track a breeding pair that has nested in a black cottonwood tree for the past four years.
An estimated 500 to 700 bald eagles winter in southern Oregon's Klamath Basin, where they feast on waterfowl that have likewise migrated south down the Pacific flyway.
Bald eagles are back, baby. They're out on Sauvie Island, around Bend, up at Wallowa Lake and throughout the lower Columbia River. Drive down Interstate 5 in late winter and you may see them in bright green fields along the freeway. Ride your bike along Portland's Springwater Trail and it's common to see a baldie giving a baleful stare from tree or transmission tower.
The state wildlife commission took bald eagles off the state endangered species list this month; it was removed from the federal list in 2007.
De-listing is an unusual action. The Canada goose, two types of peregrine falcon and the Columbia white-tail deer were previously removed from the state list, and 33 animals remain. On the federal list, 1,391 animals and plants remain listed as threatened or endangered; about two-dozen were removed because they have recovered.
The state de-listing recognizes a stirring comeback.
"It's a definite feather in the cap, if you will, for the Endangered Species Act," says Dominick DellaSala, president and chief scientist of the Geos Institute, a conservation research group based in Ashland. "In my lifetime we've recovered our national symbol."
"It is remarkable," agrees Martin Nugent, endangered species coordinator for the Oregon Department of Fish & Wildlife. "It was in danger of being wiped out in North America -- that's not an exaggeration."
True enough. In 1963, the U.S. Fish & Wildlife Service estimated only 417 nesting pairs in the lower 48 states. The near disappearance kicked people into action. The government banned the pesticide DDT, which accumulated in eagles' prey and fouled the birds' reproductive systems. Federal listing as endangered in 1978 and state listing in 1987 slammed home regulations and reality. A public education campaign shamed careless shooters; state and federal logging laws protected habitat.
It worked. By 2006, researchers counted 9,789 breeding pairs in the lower 48.
When the federal government de-listed bald eagles, the ruling reflected the species health in the country as a whole. Oregon biologists waited until they'd finished analyzing a 30-year study of eagles by Oregon State University.
Oregon's bald eagle population has grown from 65 resident nesting pairs in 1978, when the OSU study began, to about 570 now, Nugent said. Winter brings hundreds more to the state, migratory visitors to the Klamath Basin from Canada and the interior U.S.
Researchers cheer the success.
"Oh, you bet," says Ralph Opp, a retired state wildlife biologist who began studying eagles in the late 1970s. "It's been a long battle."
"Hats off on that one," says DellaSala, of the Geos Institute. He took part in OSU's bald eagle research as a post-doctoral degree student in the mid-1980s.
Bald eagles have existed in the Northwest for up to 14,000 years, and there may have been as many as 100,000 eagles in the lower 48 states in the 1780s, according to ODFW. The population declined nationally beginning in the mid-1800s due to habitat loss and shooting, trapping and poisoning. Many settlers considered them a threat to livestock.
By 1940, bald eagle numbers had declined to the point that Congress prohibited killing, possessing or selling them. But the worst was yet to come: the widespread use of DDT after World War II.
The pesticide weakened eggshells, causing them to break in the nest during incubation. In other cases, DDT interfered with normal embryo development, and breeding failed.
Bald eagles remain protected under state and federal law, and can't be killed, captured or harassed. Laws protect the trees and key watersheds eagles require for nesting and hunting. Opp, who heads a Klamath Falls group called Oregon Eagle Foundation, says the state population is "very stable."
But he adds, "We still need to keep our guard up. I think we need to be wary."
A 2012 assessment by ODFW says DDT and PCBs, although banned in 1972 and 1978, respectively, persist in the environment. No bald eagles have been killed by wind turbines, but researchers caution they must be sited to avoid breeding, foraging or migratory areas.
Bald eagles are among the most majestic of birds. Adults develop characteristic white heads and tail feathers at age 4 or 5, and have yellow beaks and talons. Large, fierce-eyed and living 20 years or more, they are graceful, powerful predators of fish, small mammals and waterfowl.
They're also opportunistic scavengers, quite willing to help themselves to roadkill and to eat sheep afterbirth in Willamette Valley fields. DellaSala recalls seeing a bald eagle steal food from an osprey, forcing the smaller raptor to drop a fish and snatching it in mid-air.
Such sightings are no longer rare.
Employees at Ross Island Sand & Gravel Co. on Portland's Southeast McLoughlin Boulevard enjoy an office window view of a bald eagle habitually perched atop an electrical transmission tower overlooking the Willamette River. It's an urban bird, most likely nesting on Ross Island.
The nesting pair at the former St. Johns landfill took over and enlarged a nest used by hawks and owls, says Mike Guebert, environmental specialist with Metro, the regional government.
Employees are so familiar with the eagles, they can tell when the birds are sitting on eggs. Usually adults show only their white heads, but stand in full view on the rim of the nest when delivering food after the eggs hatch. Within four or five weeks, young birds hop about the branches, trying their wings.
The landfill is a comeback story of its own. It was Portland's garbage pit for 50 years, spans nearly 240 acres and holds 14 million tons of trash, covered by a polyethylene liner, dirt and grass.
Now eagles live there.
"I think it means we've done our job in rehabilitating this property," Guebert says. "It's like they're our birds."
Information from: The Oregonian, http://www.oregonlive.com
Copyright 2012 The Associated Press.