National Eagle Center Studying Golden Eagles in Wisconsin and Minnesota

One of the many benefits of living near the St. Croix River is that, regardless of the season, the valley attracts an immense variety of wildlife, both resident and transitory. At this time of year we live in almost daily view of ducks and geese, swans and loons, deer and fox, muskrats and mink, ospreys and eagles. If we only look, April in Hudson offers almost unlimited wildlife viewing opportunities—especially for eagles.

There are so many bald eagles in our area that we almost become jaded to their presence. It’s easy to forget that bald eagles were endangered not so many years ago, and in some parts of the country, these regal birds will still stop traffic.

Combine the number of bald eagles we have around here with all the other raptors in the area, and some days we barely give big predatory birds a second glance. That's a mistake, I think.

For one thing, bald eagles are quintessentially American; big, bold, and beautiful. As such they are always worthy of appreciative scrutiny.

But there are also other reasons to look up every once in a while. For example, if you don't, it’s remarkably easy to overlook a rarer sight in our local skies—the golden eagle.

Thought of primarily as western bird, at least by yours truly, it's becoming apparent that the bluffs and coulees in Wisconsin and Minnesota are home to a significant wintering population of golden eagles. And since the golden eagles in our area are migratory, April is a good time to look for them as they leave our area.

Raptor expert Scott Mehus is the authority on golden eagles in western Wisconsin and eastern Minnesota. From his office at the National Eagle Center in Wabasha, MN, he looks out over the wide Mississippi River valley and on into the deep coulees and steep bluffs of the Wisconsin side of the river.

“There are probably something like 100 golden eagles wintering in Wisconsin,” Mehus says, “and about the same in Minnesota.” Mehus has been studying goldens in the upper-Midwest for 16 years and has discovered that there are far more of the birds here than anyone imagined even a few years ago.

“Each year we do a count [of golden eagles] on the third Saturday in January,” Mehus commented, “This year we had more than 100 observers and they counted 80 golden eagles on the Minnesota side alone.”

Not surprisingly, as the number of observers increases, so do sightings of the big raptors, indicating to Mehus that there may be many more in the area than we currently know about. Since the observers carefully record specific locations and times of sightings, it's possible to eliminate, or at least reduce, the chance of counting the same birds more than once.

"We used to only get anecdotal reports of a few golden eagles each year," Mehus elaborated, "Now, we're in our seventh year of formally surveying them, and it's clear the more surveyors we have, the more birds we find." The data Mehus is gathering suggests there may be yet more goldens to discover, and he hopes to attract more surveyors for next winter to expand the survey range in Wisconsin.

Unlike bald eagles, golden eagles are not fish eaters, so you’re not likely to see one swooping low over the water, or standing on a sand bar or island in the river. To see one in close proximity to the St. Croix is not necessarily rare though, since, like many birds, golden eagles use river valleys, including the St. Croix, as travel corridors.

According to Mehus, goldens typical arrive in Wisconsin in October or November. They spend the winter ambushing prey on grassy, open hilltops in the tributary valleys and coulees away from the main river.

Mehus has seen golden eagles take everything from squirrels to mature wild turkeys. “They have about 400 pounds-per-square-inch of crushing power in their talons,” he said.  That’s enough to handle just about anything the eagles would ordinarily prey on.

But there really isn’t an “ordinary” for most wildlife. Mehus has seen golden eagles chase adult white-tailed deer—an amazing statement given the size disparity involved, but a cursory internet search found a photo and report suggesting that Mehus' observation was not an anomaly.

The golden eagles in this area will began their long trip north sometime between February and May. So far as Mehus knows, there are no nesting golden eagles in the state, but never say never. According to Mehus, “They can nest on the ground, in trees, or on cliff faces.”

Mehus, and Mark Martell, of the Minnesota Audubon Society, have fitted three birds from this area with GPS telemetry harnesses. The harnesses provide regular location updates as the birds leave our area to breed and nest.

One of many things Mehus has learned from the telemetry is that eagle "GOEA46" (nicknamed Whitey) traveled east into New York state and then into northeastern Canada.  

So much for golden eagles being “western birds,” and more proof that wild things don’t read books, care about borders, or follow rules—thank goodness.

For my part, I have seen three golden eagles in the Hudson area this year, and one further up the St. Croix near Grantsburg. It’s worth taking a closer look, the next time you see what appears to be an immature bald eagle soaring over your neighborhood—it might just be the much less common golden eagle. The differences are subtle, so look closely.

The most obvious difference is that immature bald eagles have a more mottled pattern on the undersides of their wings. Golden eagles are uniformly darker than young balds. At a distance, it's also possible to mistake a golden eagle for a turkey vulture, which are dark like goldens, but have a much smaller, featherless, reddish head.

The National Eagle Center is looking for volunteers to help with its winter golden eagle surveys in this area. As part of that volunteer program, they will teach you how to identify the different species. If you would like to participate during the 2011-12  survey season, contact Scott Mehus at the center via email at scott@nationaleaglecenter.org.