Q: A cardinal has been visiting our feeders and since we live in Duluth we're wondering whether he'll stay around through the winter.

A: If you keep your feeders filled you may see that handsome red bird all winter long.

As recently as 30 years ago, cardinals were a rarity in your city. But they're now being recorded on Duluth's Christmas Bird Counts, indicating that this bird is now a winter resident, and cardinals have been nesting in Duluth in the summer.

"Their numbers seem to fluctuate quite a bit, maybe in response to difficult winters," says Dave Benson, Duluth naturalist and author. "I hear them often in different parts of the city, but I'm sure they are much more common in the Twin Cities."

Cardinals were a Southern bird, but they have an adventurous gene and have been pushing northward, with the Department of Natural Resources noting the first sighting in Minnesota in 1875. By the 1930s they'd become established in the Twin Cities, and kept on pushing north — Duluthians began seeing them regularly in the 1990s.

Late loon?

Q: There was a loon swimming on our lake until very late in the fall and I worried about it not leaving on migration. Do you think it was OK?

A: I wouldn't worry about the solitary loon. Even though their parents may have left the state several months ago, juvenile loons tend to stay late into the fall to build up their flight skills and hone their fishing abilities. When they feel ready, they gather up with other juveniles and head for the Gulf of Mexico.

Seeking shelter

Q: We have several birdhouses in our yard and a downy woodpecker seems to come in to sleep in one at night. We've never seen this before — is he just trying to find a warm place to sleep?

A: You're exactly right, that's what the downy is doing. Woodpeckers excavate and then sleep inside tree holes at night. The lucky few, like your downy, find ready-made cavities in the form of bird nest boxes, thereby saving themselves the work of drilling into a tree to make a night roost.

Daffy duck

Q: We spied an all-white duck in a group of mallards on a small city lake the other day. Could this have been an albino mallard, or maybe a snow goose?

A: Chances are that the white bird was a domestic duck; these are sometimes seen with mallards on city lakes. Someone may have released the duck or it escaped from captivity. It's also possible that it was either an albino mallard, if it had pink eyes, or a mallard lacking pigment in its feathers. The one thing it probably wasn't was a snow goose, because you would have noticed a size difference.

Hearing hoots

Q: Could we have been hearing great horned owls hooting as early as Halloween?

A: You certainly could hear owls serenading each other around that time, since these big birds begin their courtship in autumn. They begin nesting early in the year, since it takes weeks before young owls leave the nest and several months to learn from their parents how to hunt.

Silent season

Q: Winter seems so quiet without the songs of birds. Can you tell me when they start up again?

A: You're right, birds become much less vocal after the breeding season, although it's cheering to hear nuthatches "yank"-ing and chickadees making their cheery "chicka-dee-dee" calls as they forage in winter. I count cardinals as the first birds to begin courtship singing, as early as January each year.

Crow air force

Q: While walking through my neighborhood recently I heard a loud cacophony of extremely agitated crows. Something definitely was up, and as I gazed at the sky I saw the source of their excitement, a large eagle circling overhead. Then a remarkable thing happened: Four or five crows in formation, like a little air force, went after the eagle. As they approached him the crows would swoop off to be replaced by four or five other crows. The eagle remained calm throughout this attack but gradually did soar away. I came away with new respect for these brave little fighters.

A: Thanks for sharing your crow story. I love any and all anecdotes involving these savvy black birds, and yours is a fine one.

St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.