High above Duluth, raptors offer a sign of springby Stephanie Hemphill, Minnesota Public Radio
Duluth, Minn. — About this time of year, we're all looking for signs of spring. The first bulbs peeking up, the first robin. In Duluth, one man is seeing a lot of signs of spring -- and they're all flying north.
In the fall, people from all over the place travel to Duluth's Hawk Ridge to watch the raptors as they head south for the winter. Well, now they're coming back, and bird experts say it's important to count the spring migration too.
Karl Bardon leans against his Subaru station wagon, basking in the sun and watching for birds. He's parked at an overlook on Duluth's Skyline Parkway, high above the busy port.
"A lot of people come up and expect to see birds without using binoculars," he said. "But probably 90-percent of the birds we see, we find by scanning with binoculars."
He moves the binoculars across the sky, left to right, top to bottom.
Behind the parkway there's a rugged rock cliff and a golf course. But the view in front is of a very busy place: the Duluth-Superior port, with railroad yards and ore docks, the sewage treatment plant, the freeway, and several bridges. The birds are using this place as a transportation corridor, too.
Bardon points out a merlin, a small falcon. It's flying west, so Bardon says it's probably a local bird.
"There's merlins that nest right in the city," he says.
Bardon is the official counter here. He calls out the birds as he sees them, to alert the other birders who've joined him. Now he looks through the scope.
"There's a couple birds over the ski area, a bald eagle and a red-tail."
Bardon uses binoculars to find the birds, and then turns to the scope to identify those that are really far away.
"Or if I can tell what they are, I like to know their age and their sex, too," he said.
Bardon keeps a clipboard with a tally sheet, where he writes all this information down.
Hawk Ridge posts the results on its web page, and there's a national tally too. There are about 50 places in North America where people count migrating hawks in the spring. Duluth gets the most bald eagles and red-tailed hawks.
They count about 26,000 birds flying over in the spring, but a lot more in the fall, about 94,000. That's mainly because in the fall, when the birds get to Lake Superior, they hug the shoreline to avoid flying out over the lake. And that funnels them in a concentrated stream over Hawk Ridge on the eastern edge of Duluth. In the spring, they're coming from all points south and there's no natural funnel.
Bardon watches a small group of hawks gathering in a kettle, including two red-tails.
"Presumably they have a thermal," he says. "When they find a thermal they'll all circle in it to gain altitude. And once they get up to a certain height they can just glide for miles. "
Janelle Long says this spring count is important because it gives some indication of how the birds fared in their wintering grounds. Long is the executive director of the non-profit group that runs Hawk Ridge. Many of these birds fly all the way to Central or South America, where they use a lot of pesticides.
"If the pesticides are bio-accumulating in the food that they're preying on, that's going to affect the raptors," says Long.
Raptors are a good indicator of environmental health, because they're so high up on the food chain. They eat smaller animals, and the poisons in those little animals build up in the raptors' bodies. And raptors are easier to count than most of their prey.
But they've only been collecting data here for nine years, and Karl Bardon says that's not enough time to indicate any trends.
"There's a red-tail going through that cloud, that's pretty," he calls. "You should be able to see him, naked eye, in those waves. He's circling. Now he's just going to glide north. He's got the lift he wants and he's on his way."
Bald eagles come through here early in April; Bardon has already counted 3,000 this year, which is about average. Later this month, he'll see osprey, turkey vultures, and then come the hawks -- sharp-shinned, broad-winged, red-tailed, and rough-legged.
There are also plenty of songbirds along the way.
- Morning Edition, 04/13/2009, 7:25 a.m.