A different kind of SNOW BIRD

In twos and threes, gulls come wheeling over Lake Calhoun a few minutes before dusk on a gray November day. This is their roosting place. Hundreds of gulls will spend the night on the water.

Most of these birds are ring-billed gulls, common in Minnesota during the summer. Some are herring gulls. But in that flock there also will be gull species seen here only when it's cold.

In ornithology-speak, these uncommon visitors are given an unflattering name: vagrants. That means they're being seen outside their usual range.

Visiting thrushes

But gulls aren't the only vagrants. We're likely to get other birds to brighten our winter. One of those will be the varied thrush, a cousin of the robin with vivid black markings on its orange face and breast. Although the varied thrush usually winters along the West Coast, some regularly wander east. Last winter, one made it to St. Paul, where it visited a crabapple tree daily. (Note: Apple trees are good places to look for this bird.)

Townsend's solitaire is another western bird that makes winter visits here. It's a high-mountain thrush named for the man who collected (i.e. shot) the first specimen. Their winter range correlates with the availability of juniper berries, a food item.

A solitaire has been seen at the Anne Lake campground in Sherburne National Wildlife Refuge each winter since 2005. Al Schirmacher, a Princeton-area birder, has seen the bird each year in the same large deciduous campground tree.

And then we have the gulls.

Gull ID

Some people say all gulls look alike. And it's true that identifying these large white, black and gray birds involves careful examination of what you might call picky details. You have to check things such as wing tips, leg color, bill color, eye color and the subtle shades of gray that distinguish some species from others.

My friend and fellow birder Chet Meyers saw a Thayer's gull on Lake Calhoun earlier this fall.

"You saw the dark eye, right?," I asked. Thayer's gulls have brown eyes. That distinguishes them from look-alike herring gulls, which have yellow eyes.

"Well, yes, but it was just off shore," the ever-modest Meyers said. Then he went on to list the other keys to identifying a Thayer's gull, "and the head was smaller and rounder, and I did see the whiter feathering under the wing."

Jim Mattson, another birder who likes gulls, is often at Black Dog Lake this time of year. When our lakes freeze, many metro gulls move to Black Dog, which is east of the Interstate 35W bridge over the Minnesota River. The lake is used to cool water discharge from the power plant there, so it doesn't ice up. (Note: It's a good place to watch birds all winter.)

Thayer's, glaucous and greater black-backed gulls usually are early arrivals, said Mattson.

Other vagrants surely will be seen around the state this winter. In years past, birders have found rosy-finches, purple sandpipers, bramblings and a fieldfare. The latter is a thrush from Europe that made a once-in-my-lifetime appearance in Grand Marais. It's not very likely we'll be seeing one of those again any time soon. But unusual gulls are a sure bet.

"They're on their way," Mattson said, "rest assured."

If you go looking for them, you might want to grab an ID book. Mattson also suggests you break out the long johns.

Jim Williams, a life-long 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 two-jays@att.net.