Researchers are tracking a golden eagle found in southwestern Wisconsin to learn if this western bird is broadening its range.
A golden eagle from the prairies of southeastern Minnesota and neighboring Wisconsin is taking some researchers on an Arctic adventure.
Golden eagles are relatively unknown in Minnesota, infrequently seen, counted in small numbers and for a long time thought to be lone wanderers from the west.
These huge brown birds do winter here, however. They hunt for prey on the steep grassy slopes in the driftless area. Any given winter, about five dozen golden eagles cross the Mississippi River from Minnesota to Wisconsin and back.
Goldens are essentially birds of western North America. They nest all the way up to the Arctic coast in Alaska and Canada. Their range maps show nothing along the western edge of Hudson Bay. But that's where Whitey is.
Whitey is the name given to a golden eagle by Scott Mehus, education director of the National Eagle Center in Wabasha, Minn. Mehus kept seeing a light-headed bird in a Wisconsin valley. He called it Whitey. When Wisconsin game officers delivered an injured golden eagle to Mehus last November, he knew he was looking at the bird he'd nicknamed.
Whitey's timing was perfect. Mehus and Mark Martell of Audubon Minnesota had been trying to trap a golden so they could attach a radio transmitter to it. They wanted to know where goldens that winter in Minnesota and Wisconsin go in the spring, where they summer and possibly nest. Their efforts to trap a golden eagle failed. It was a leg-hold trap set for a coyote that caught the bird. And that's how Whitey came to be the most studied golden eagle in this part of the country.
North to the Hudson
Whitey spent time at the University of Minnesota Raptor Center in St. Paul between his release from the trap and his release back into the wild.
The trap had punched life-threatening holes in one of his legs. Dr. Louis Cruz grafted skin to restore the eagle to flight condition. When he was released in late March, it was with a tiny, solar-powered transmitter.
In mid-June, that transmitter placed Whitey at 65 degrees north, just west of Hudson Bay's South Hampton Island.
If and when Whitey settles down this summer, Canadian game researchers will try to find him. Project participants -- including the Department of Natural Resources in Minnesota and Wisconsin, the Upper Mississippi River National Wildlife and Fish Refuge and Audubon Minnesota -- want to know what he's doing up there, and if he's doing it with other goldens.
It's possible that other goldens are breeding there, although probably not Whitey, because he got a late start this year.
"Ideally, we want to track a nesting pair of eagles to learn if they stay together during the winter," Mehus said. "We'd like to prove that they have nesting territories in that part of Canada. They're not known to nest there."
Know your eagles
Golden eagles are big brown birds. At first glance, immature bald eagles are big brown birds. How do you tell one from another?
Territory is one clue. "Goldens are not river birds," Mehus explained. "Birds seen along rivers are likely bald eagles." Flight is another. "Goldens glide with a slight V to their wings," he said, "not as much angle as a turkey vulture, but more than the straight-line wing-to-wing profile of a bald eagle." Goldens also have smaller heads and smaller bills than bald eagles.
Golden eagles are named for the color of their crown. If you see a big brown bird with a golden crown and a transmitter, it might be Whitey the Research Eagle.
Jim Williams, a lifelong birder, is a member of the American Birding Association, Ducks Unlimited, Pheasants Forever and Delta Waterfowl. Join his conversation about birds at www.startribune.com/wingnut. He can be reached by e-mail at firstname.lastname@example.org.
You can track Whitey's movements since his release in Buffalo County, Wis. Go to mn.audubon.org/news-events/golden-eagle-42-release. (Although his nickname is Whitey, the bird's official moniker is number 42.)