Q: We'll be visiting a warmer climate for three months this winter and wonder if we'll be doing birds harm if we stop feeding them.

A: That's a very timely question and one faced by many others as they prepare for winter getaways. Our backyard birds don't depend on our feeders for all their daily calorie needs, instead incorporating food from a variety of sources, including hibernating insects, seeds in garden beds, leftover berries on bushes, carrion found in nature and food from bird feeders. Except in extremely inclement weather, our feeders supply a quarter or less of bird calories.

What I recommend is that you begin to taper off on the amount you fill your feeders, putting out less and less food each day in the month before you depart. As the food runs out earlier each day, birds will look to other sources to supply their needs. Take the feeders in when you go, then hang them outdoors again in the spring.

Your birds will gradually return when they notice filled feeders as they pass by on their foraging routes. One other thing you can do to help backyard birds is to plant native flowers (monarda, liatris, aster, goldenrod, etc.) and shrubs (dogwood and virburnum, etc.) next spring. These will serve up seeds and berries in fall and winter.

Caching crow

Q: I watched some interesting bird behavior recently: A crow was standing on the ground and staring intently at something at its feet, then placed a leaf on top of whatever it was, pressing it down with its beak. It did this a couple more times, then nonchalantly walked away. When I went out to check I found a piece of bread under the leaves. I'm wondering why the crow didn't just take the bread away, rather than hiding it.

A: I loved your careful observations of one of my favorite birds. I've seen blue jays (crows' cousins) doing a similar thing with peanuts, and what these birds are up to is saving food for later consumption. The poor crow, though — chances are slim that its snack was there when it returned. Although you noticed that the bread had disappeared by the next day, it's more than likely that a squirrel or another bird pounced on the hidden treat within hours of the crow caching it.

Squirrel foiler

Q: You mentioned in a recent article the kind of feeder that has a dome to be raised or lowered. Can you tell me more about it? I'm just about ready to stop feeding birds because squirrels take all the seed.

A: I swear by domed feeders since they keep most rain and snow out of seed and, if set up correctly, will deter squirrels, too. This will take a bit of an investment, but I swear if you follow these steps you will never again be bedeviled by those furry rodents.

First, acquire a domed feeder, and then place it on top of a shepherd's hook pole sunk into the ground. Fit a metal predator guard (the kind that looks like a witch's hat) around the pole, and place pole and feeder at least 15 feet from any structure or tree (to foil jumping squirrels). We've got several of these pole systems in place and have never, ever had a squirrel in the feeders.

Eagles in the 'burbs?

Q: I noticed an eagle flying fairly low over my suburban neighborhood recently. We're several miles from open space or the river. I'd never expected to see an eagle so close by.

A: Eagle sightings are becoming anything but unusual around the metro area, since so many eagles nest along our rivers and spend the warm months here. The raptor you saw might have been traveling between waterways to fish for a meal, or checking lakes for an injured duck that might be an easy catch. While no longer unusual, seeing one of these big birds up close is always a splendid thing.

Flu carriers?

Q: We heard so much about the avian flu this summer, but I never saw anything about what ultimately caused the outbreak, except for a link to migrating birds. Has anyone looked at pigeons, which are around most farms?

A: You raise an interesting possibility, and it seems that the experts are not quite sure how avian influenza enters commercial poultry populations. The finger still seems to be pointing at migratory waterfowl, instead of barnyard birds like pigeons. Experts believe that ducks and other water birds carry the virus and that their feces spread it somehow. Interestingly, even though the Minnesota Department of Natural Resources has tested thousands of bird samples the agency has found no signs of the pathogen. It still believes that migratory waterfowl are the probable cause, however.

Cardinal nests

Q: I put out a birdhouse for cardinals last summer, but they didn't seem to use it. What can I do to make it attractive to them this spring?

A: Sorry to report that there's nothing you can do to inspire cardinals to use your birdhouse. This species is hard-wired to build its nests outdoors, in a shrub or tree. Most of our backyard birds are like this, and are called "outside nesters." A few birds, like chickadees, bluebirds and tree swallows, are "inside nesters," using a cavity in a tree or a birdhouse in the right habitat. I'd keep that birdhouse in your backyard and see if a chickadee doesn't adopt it this coming spring. Just make sure house sparrows don't set up housekeeping, because these nonnative birds are very aggressive toward other cavity nesters.

Wintering loons

Q: Where do loons go in the winter?

A: Loons from Minnesota's lakes migrate to the Gulf of Mexico to spend the winter diving after small fish. This year's young loons fly directly to the Gulf over two to three days in autumn, while adult loons may head eastward to spend some weeks in large groups on Lake Michigan and other lakes before heading south. Minnesota's DNR is studying loons' migratory patterns and has placed tracking devices on a number of them. You can view these loons' migratory routes at bit.ly/minnloons.

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.