Majestic bald eagle adapting to urban life
Seattle Times science reporter
A funny thing happened on the bald eagle's long flight back from decimation. America's symbol of wildness became a city kid.
Hammered by hunters, then DDT and other forces of civilization, the eagle retreated for decades to the hinterlands of Alaska, British Columbia and our own San Juan Islands. Only in recent years has it returned to the salmon-rich river banks of the Skagit, Sauk and Nooksack.
Now, with much of the wildest eagle real estate occupied, the bird has taken to the bluffs of Seattle, the high trees of Mercer Island and Green Lake, a host of parks and an aerie by the industrial redoubt of Harbor Island. A pair in a Kent back yard have raised several clutches before a live Internet audience.
In the process, the bird is rewriting its résumé, from national symbol to endangered-species poster child to opportunistic urbanite. The day may come when this is a problem, when eagles come into conflict with landowners over development or the bird's potential taste for cats and small dogs.
But given its grandeur, the urban eagle is hard to knock, gracing tens of thousands of city dwellers with routine glimpses of the wild in the Northwest's least wild places, as well as a front seat to an adapting species.
Last month, the Audubon Society's Christmas Bird Count found 43 bald eagles in Seattle alone.
"It always seems somewhat out of context to be sitting in this sea of concrete and have a bald eagle flying over," said Peter Dunwiddie, who watches eagles and falcons from his downtown 10th-floor office at the Washington chapter of the Nature Conservancy, where he is director of research programs. "Just the fact that they're around and able to fly through here to me suggests we're doing some things right."
Back when Seattle was a chief, not a city, there were an estimated 6,500 bald eagles in the state. Then came more than a century and a half of timber cutting, commercial salmon fishing, lost wetlands and estuaries, indiscriminate shooting and, the coup de grâce, egg-thinning chemicals like DDT. According to the state Department of Fish and Wildlife's 2001 bald-eagle status report, those pressures whittled the eagle numbers down to 105 breeding pairs in 1980.
It was a huge loss, and not just because the bird is a national symbol.
With a 7-foot wingspan and females that can weigh up to 14 pounds, the bald eagle is one of the largest birds of prey in the world. At maturity, which comes after five or six years, it cuts a striking figure against the sky, with a bone-white head and tail that gave it the name "bald," from the Old English "balde," or white.
In a dive, it can top more than 100 mph. Its steely, indifferent eyes are five to six times more powerful than a human's.
With the banning of DDT in 1972 and increased protection of eagles and their habitat, the bird's population took off, growing 10 percent a year. By 1998, there were 664 occupied nests statewide.
Now, the status report theorizes, the bird's population is approaching the point where the environment may not support more eagles.
Moreover, a younger eagle looking to nest faces tough competition for remote habitat, with established eagles guarding their territory fiercely, even to the death. So younger birds appear to be shedding some of the eagle's traditional wariness of humans and building nests closer to civilization, said Derek Stinson, a biologist for the state Department of Fish and Wildlife and a co-author of the status report.
"They're adapting, basically, becoming more tolerant of disturbance," Stinson said.
Stinson has seen eagles nesting in the tony uptown section of Port Townsend. At the Woodland Park Zoo, a wild pair have bred in the elk yard, which is, fittingly, near the raptor center. Tom Aversa, one of the zoo's raptor keepers, has seen more than half a dozen eagles swirling over Phinney Ridge.
Patricia Thompson, King County urban-wildlife biologist for the Department of Fish and Wildlife, has seen them perching on Green Lake's little island and near Bellevue's Chisolm Beach.
"West Marginal Way has a new one by the (Continental) Van Lines building up on that greenbelt," said Thompson.
Nests all around
There are nests on Mercer Island looking across Lake Washington to nests in Seward Park; a recent aerial fight between birds on each side left one dead. Eagles are on Hunt's Point and by the West Seattle Bridge and up from Alki Beach near Salty's. They are in St. Edward State Park in Kenmore and Finn Hill's O.O. Denny Park, swooping on to rafts of wintering coots.
When Eugene Hunn wrote "Birding in Seattle and King County" in the early '80s, he found a total of three nest sites. "Now there are probably 20 or 30," he said.
Eagle-housing needs are simple — 1 br, water vu — but with a fussy detail or two. The birds prefer the tallest tree in the neighborhood. It helps if a tree is strong enough to hold a nest that, with annual additions, can weigh as much as a small sports car.
Food is key, but the birds aren't picky eaters. Typically they flock to prodigious runs of salmon, like those rotting these days on the Skagit River, but they'll also make a meal of tractor-killed European hare, other birds, the occasional crustacean, roadkill deer, seabird eggs, blue-heron nestlings and mammals like raccoons, muskrats and opossums.
Their opportunistic eating habits are so wide-ranging that dozens of eagles in the United States and Canada have died of drug overdoses after feeding on euthanized mules, cattle and cats dumped in landfills.
"I had a co-worker that called them 'our national scavenger,' " said one state Fish and Wildlife worker.
Loraine Robbins, of the "EGL LDY" license plate and Fish and Wildlife's Web-based eaglecam, has found beneath her birds' nest a dead duck, trout, perch, a squirrel, lots of crow feathers and bones that looked like they came from a beef roast. She has seen in the nest what looked like a koi, a Japanese ornamental carp.
Not the most feral of diets, but her birds still represent to her some kind of wildness.
"Being that they're here, it's telling me the area hopefully won't turn into downtown Seattle, downtown Portland, downtown Auburn, downtown Kent," she said. "When the birds are doing well, when the species are doing well, then the land is doing well."
Living the urban life
Biologists tend to agree the bird's growing urban population is for the better but see it more as a sign of an adapting bird than a wild city. And eagles and humans are already competing for coveted shoreline real estate.
"Both eagles and people like to live on the shoreline," said Stinson, the status report co-author. "Eagles like to build nests in trees, and people like to cut them down so they have a view."
Almost all the state's bald-eagle nests are within 3,000 feet of a lake, river or marine shoreline. Two-thirds of the state's nests, and three-fourths of the mostly-urban nests in King County, are on private land.
The birds have some protection in a state law requiring management plans for development near eagle habitat. But birds and people might develop other conflicts.
"I've heard some concern that they might adapt so well that they become a little too urbanized," Stinson said. "That is, they start to get in trouble and become a nuisance, like they sometimes do in Alaska, which would be unfortunate. They start taking pets or begging for food outside restaurants. That sort of thing would be unseemly."
Eric Sorensen: 206-464-8253 or firstname.lastname@example.org. Natural Wonders appears every other Monday.