Our Window on Nature

. . . exploring the world around us

Eagles on the Agenda

Filed under: Birds — Lowell Christie -- November 2, 2014 @ 7:30 am

Bald-eagle-with-fishEach autumn for more centuries than man has existed on the North American continent, bald eagles have temporarily abandoned their northern breeding grounds for winter sojourns farther south. Early man lacked the ability to interfere with this migration; not until man was civilized enough to use guns and poisons did the vagabond eagle face peril. Only then could humans make a sport of shooting eagles and poison the earth with DDT, in addition to draining and paving the wetlands that the eagles needed. The bald eagle became an endangered species in the very country that claims it as its national symbol.

Today man is making amends. He builds reservoirs for flood control and then stocks them with fish, at the same time providing eagles with a reliable food supply. He establishes refuges for migrating waterfowl that, aside from providing sport for hunters, serve up eagle food in the form of wounded ducks and otherwise incapacitated birds. Of equal importance, he outlawed the slaughter of predatory birds, thereby making the eagles’ migratory passage less hazardous. As a result of these efforts, once again we can enjoy the sight of bald eagles in the wild.

In this month’s column we will focus on eagle viewing possibilities west of the Mississippi – not because there are no wintering balds in the East, but because the birds have not built up in as great numbers there. So, if you’ll be traveling in the western United States between now and early spring, keep your eyes open; there may be an eagle on your agenda.

The classic spot from which to view bald eagles this month and next is Blankenship Bridge at Glacier National Park. In a typical year, peak viewing day at this location will produce several hundred birds in the seven-mile stretch between Lake McDonald and the bridge. The eagles arrive with the spawning salmon, and when the harvest is over they continue their southward migration.

Fish eaters by preference, bald eagles have learned to follow the kokanee spawning season. Wherever man has introduced kokanee into inland bodies of water eagles have found them, because mature kokanees swim upriver to spawn and then die, as do their oceangoing counterparts. Spent salmon is gourmet fare for eagles. Rangers at Glacier National Park limit sightseers’ approach so as to protect the eagles, but you’ll be able to move close enough to enjoy a memorable sight of the birds feeding or loafing a dozen to a tree.

If a visit to Glacier in November sounds too chilly for your blood, many other reliable wintering spots for eagles await your eyes. In Washington’s Puget Sound, San Juan Island hosts a population of more than 75 birds. The nearby Skagit River supports several hundred birds during the salmon season; however, the eagles disperse soon after the fish die out.

Down in California, check out wildlife refuges such as Tule Lake, Klamath, Sacramento, and Gray’s. Once the spawning season ends, bald eagles can’t find enough fish to fill their hungry bellies; so, they turn to their second choice – birds. Wherever there are large populations of waterfowl, bald eagles gather. Not fleet enough of feather to snatch a healthy duck, they focus on the sick and those that have been wounded by hunters.

Most bald eagles pause just south of where the lakes freeze solid (as do the greater number of migratory waterfowl), so lakes and reservoirs farther south host eagles in smaller numbers. While paddling around the Colorado River marshes northwest of Yuma, Arizona, we watched a bald eagle snatch dinner from right in front of our canoe. We were close enough to hear the swoosh as he plummeted and the sweep of mighty wing beats as he lifted off with his prize. Then, after reversing the fish in his talons so that the head pointed into the wind, the eagle flew off to a perch and devoured his prize.

The West Coast doesn’t receive all of the wintering bald eagles, however. Reservoirs exist throughout the Great Plains and the intermountain West; each may have a wintering eagle population. Wildlife refuges are situated along the Mississippi and Missouri rivers; these are excellent viewing places as well. Check below hydroelectric dams, too. Often fish become caught in the turbines and are stunned or killed; thus, eagles soon learn to hang around near the tailrace of the dam waiting for casualties to appear.

You may witness aerial chases in your eagle watching. Not yet skillful in capturing prey, immature bald eagles often harass the adults in the hope that they will drop their meal. Sometimes the young eagles attack from below, turning over in midair to grab the prey in their talons. Then it’s a brief contest of wills before one or the other bird lets go.

The fight is slightly less evenly matched when an eagle tangles with an osprey. The smaller osprey does the work; however, the eagle usually claims the prize.

When you travel in the northern states, watch for communal eagle roosts. Such roosts are occupied by wintering bald eagles only and never those that are breeding. Ignoring other suitable perches, most of the local population clusters in a single tree, jostling and squabbling over the most prestigious branch. Don’t inspect them too closely – even though eagles are less sensitive to intrusion during this season, they still will be driven off if there is too much pressure from man. You wouldn’t want to deprive others of the sight of this spectacular phenomenon.

These represent only some of the exciting opportunities that our national symbol offers winter travelers. With all of the California condors taken into captivity [true when this was originally written], eagles are our largest and most impressive wild birds. Man’s conservation efforts make it likely that we will continue to see bald eagles making spectacular dives for food, soaring en masse on a thermal, or roosting 20 or 50 to a tree. We have done so much to destroy the natural world around us that it’s nice to be able to report that, thanks to us, bald eagles are still around.


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