Sam Cook / Forum News Service, Published January 26 2014
Snowy owls on the rise in Midwest
He’s sitting on a gentle rise that slopes to the south, catching the sun on this 20-below-zero morning. If you were just driving by, you’d never notice him. He would be one more lump of white on a broad field of snow.
Duluth wildlife photographer Michael Furtman is watching the bird from the road, holding a long telephoto lens. He’s hoping the bird will move closer to the road and offer him a chance for good photos.
Why this snowy owl has come to sit here, in this field near Duluth on a January morning, is not clear. He belongs in the Arctic, on the tundra, eating lemmings. But this winter, hundreds and hundreds of snowy owls have left their home territory and appeared on fields and airports and lakeshores in the United States. Some have been seen as far south as North Carolina, and one ended up in Bermuda.
Birders call such a movement an irruption. The irruption began in the Northeastern U.S. and has gradually spread to the Midwest. Wisconsin birders have seen nearly 200 snowies this winter. As of Friday, 118 snowy owls had been seen in Minnesota, according to Duluth birder Mike Hendrickson.
It isn’t uncommon for a handful of snowies to hang out around the Duluth harbor or in Superior, Wis., most winters. One. Two. Four or five. Duluth’s David Evans sees them almost every winter. He holds the federal license required to band them. He traps and bands them most winters as part of a long-term study. This winter has been good so far, he said.
“I’m up to eight,” Evans said Monday.
And birders in Minnesota are seeing them across the northern part of the state.
All about lemmings
Snowy owls are thought to come south when the Arctic population of lemmings is low, seeking mice and voles here. But they are also thought to come in some years when the lemming population is high, as it is this year.
“When there are big lemming populations, snowies will have a big hatch year, and there will be a lot of young birds,” said Ryan Brady of Washburn, bird monitoring coordinator for the Wisconsin Bird Conservation Initiative of the Wisconsin Department of Natural Resources.
Apparently, in such years, even with abundant lemming populations, there will be too many snowies for the prey base, and some will come south. Many of them are immature or hatch-year birds. There have been plenty of immature snowies in this irruption, but also some adults, Brady said.
Furtman has been photographing snowy owls for a couple of weeks. Snowy owls are a treat for birders to see, he said.
“First, they’re rare here in Minnesota,” Furtman said. “Even when we know they’re around, they’re hard to find. They’re secretive. And it’s a thrill to see something from that far away here in our backyard.”
Duluth’s Brad Trevena and his wife, Lynne, watched a snowy owl feeding on a rabbit carcass in their backyard this past week.
“We’ve seen some cool things in our yard, but this is one of the best,” Trevena wrote in an email.
The last big snowy irruption in Minnesota was in 2011. This is not to be confused with irruptions of great gray owls and boreal owls that have occurred in recent years. Those are owls of the boreal forest. In irruption years, they typically show up in the hundreds, but in the winter of 2004-05, an estimated 5,000 great grays, boreals and hawk owls moved from Canada into Minnesota. They were starving, and many turned up dead.
The snowies, though, don’t seem to be in tough shape, Brady said. They’ll set up territory in some Arctic-looking open area like a field or along an airport runway, looking and listening for mice or voles. Some will stay principally on one territory. But this winter, more than in other winters, Evans said, the snowies he has seen have been moving around, using different territories or disappearing entirely.
“Most are not sticking around,” he said. “They’re bouncing around and moving. I’ve seen between five and 10 that I saw once and never saw again.”
Unlike boreal forest owls, snowy owls prefer wide-open areas, said Duluth birding guide Erik Bruhnke of Naturally Avian Birding Tours.
“Snowy owls are often found in areas reminiscent of their homes in the Arctic tundra, areas that are vast expanses of land with a perching area. If there’s a little bluff or an overlook of the flat expanse, that can be good,” Bruhnke said. “Or a flat area with light posts.”
The deep snows this year don’t seem to be bothering snowies, North America’s heaviest owls at 4 to 5 pounds. They can dive far enough into the snow to catch their prey.
Snowies are more generalists in their feeding than some other owls, Brady said. Researchers in the East have begun tracking snowy owls with small transmitters to watch their movements, Brady said. The results have been somewhat surprising.
“A lot of owls near the water are homing in on ducks,” Brady said. “There’s a bird tagged in Maryland or New Jersey doing all kinds of crazy stuff. It’s flying out at night over the ocean, eating ducks. A number of the coastal birds do that. I’ve seen them take ducks here on Chequamegon Bay.”
Sam Cook is the outdoors writer for the Duluth (Minn.) News Tribune