Bluebirds aren't blue with cold

Q: We spotted four bluebirds near our home in early January. Are they slow to migrate or are they thinking of roughing it through the winter like so many robins do?

A: Seeing bluebirds surrounded by snow strikes some of us as surreal, since we associate them with summer weather. But you can rest assured that, unless nighttime temperatures drop far below zero, these small blue thrushes will be all right. Like their robin cousins, as long as they can find food — fruit and berries, at this time of year — and water to drink, they can survive. Since they're short-distance migrants, if our weather becomes too bitter they may head southward.

Q: A large flock of pine siskins, 75 or so, has been visiting my feeders, but now I'm finding dead ones around the yard. What do you think is going on?

A: Something is very wrong. While it's sometimes tough to pinpoint the cause of a big die-off like you're seeing, the two main possibilities are contaminated food or disease. There have been reports this winter of siskin die-offs due to salmonella poisoning in some cases, avian conjunctivitis in others. Birds that congregate in flocks can spread illnesses quickly.

The first thing to do is take down all the feeders the siskins have been using, toss the seed and clean the feeders carefully. Rinse them with a solution of one part chlorine bleach to nine parts water, then rinse again thoroughly before refilling with food.

Q: You recently wrote about how birds need water in winter, but I'm reluctant to get a heated birdbath. I've heard that birds will bathe in the cold, then fly off and freeze to death.

A: You make a very good point, and I should have added a cautionary note to that earlier advice: Yes, birds need water in winter, and a heated birdbath provides a reliable source for a drink. But some birds will try to bathe, even in the cold, to keep their feathers in good condition.

When temperatures drop below 20 degrees, please put a board or other barrier across the center of the basin. This should allow birds to drink, but not to bathe. The other evening at dusk, when the temperature hovered around 12 degrees, a cardinal stepped into my birdbath basin. I ran out to shoo him away and quickly put a board across the top — it was just too cold for birds to bathe safely.

Q: My father had an albino sparrow at his bird feeder this summer. How rare is this?

A: If the bird was all white with pink eyes, then it truly was an albino and thus a fairly rare bird. A 1965 compilation of reports of albino birds showed robins and sparrows as having the highest incidence of albinism, about 8 percent in robins and a little more than 5 percent in house sparrows. But these are two species that live close to humans, so it's possible that albinism is reported more often in robins and sparrows.

If your father's sparrow was very pale but still had dark eyes, then it had a condition called leucism, which also is rare.

Q: I'm glad you wrote recently that bird feeders account for only about 25 percent of a bird's diet. I have shared this with my wife to show that we don't have to dash out to find a suet source at 3 a.m. to forestall a mass extinction at sunrise of all suet-eating birds in our neighborhood.

A: I hope this isn't a cause for controversy in your household, because you've both got right on your side. Birds won't starve if they've come to count on a feeder and suddenly find it empty. But there's no denying that it's a real benefit to birds to regularly find a source of high-energy food in the morning, after a long winter's night, and again at dusk, when they need to top off their stored fat to make it through the long night to come.

Q: I'm looking for an inexpensive winter project to do with my 2-year-old grandson, who lives near a marsh and is interested in birds.

A: It's great that you are looking for ways to nurture your grandson's interest in birds and nature. How about creating a homemade bird feeder together? Then all you'd need to buy would be some seed.

Here's a site with a video showing how to build a feeder from a plastic milk jug: www.squidoo.com/homemade-bird-feeder (you'll need to scroll down the page). Here's another "how to" site, this one for a fairly elaborate feeder made from a plastic bottle: www.recycle-crafts.com/homemade-bird-feeder.html.

Fill either one with black oil sunflower seeds or safflower seeds and sit back and watch the birds come to feed. Hang the feeder so squirrels can't reach it, either from a branch with a squirrel baffle above the feeder, or from a pole sunk in the ground.

Q: Woodpeckers have almost completely stripped the bark from a tree near my yard. Is this usual?

A: It's not unusual for woodpeckers to strip all the bark off a tree in the process of looking for insects beneath the bark. The woodpeckers aren't killing the tree; instead this almost always indicates the tree is already dead or dying.

Q: What size prey does a red-tailed hawk eat?

A: Even though they look quite large, red-tailed hawks weigh only about 1 ½ pounds (males) to up to 3 pounds (large females). These hawks like to catch prey and lift off to eat it in safety, but they can only lift about half their weight. Their diet is made up of small to medium-sized rodents, rabbits, pheasants and quail, as well as snakes and squirrels.

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