Q: What's the rule about feeding birds in the fall when you know you're going to be away from January through March? Would it be better for the birds not to start at all?

A: That's a good question and I'm glad you asked it at this time of year, since many other people who feed birds face this same dilemma. The birds in your back yard in winter get their daily food quota from many different sources, and feeders are only a small part of that, maybe 25 percent at most. However, on very cold days and early in the morning and late in the afternoon, birds may come to rely on your feeders for a quick burst of needed energy.

What I recommend to those who will be away for a long period is that they continue to feed birds throughout the fall, but gradually taper off, putting out less and less seed each day during December. As the food runs out earlier each day, birds will be compelled to find substitute food sources, either in the wild or at other bird feeders. Near the end of the month, you'll stop adding seed entirely and can bring the feeders indoors. Then, when you return, you can set the feeders out again. Birds will gradually return as they fly by on their foraging routes and notice that seed is available again.

Fiends for peanuts

Q: The blue jays love the peanuts in the shell that I put out for them, but I'm wondering whether they eat them right away or save the nuts for later? After flying away with a peanut, it seems each jay is gone for only a minute, or even less, before coming back for another. And I also wonder how they eat them — do they swallow the peanut, shell and all?

A: You've observed a fascinating element of blue jay behavior: They love peanuts, in fact are almost obsessed by them, and will take as many as you put out, returning again and again until all the nuts are gone. A bird will pick up a nut and fly off to hide it under a leaf pile, in a shallow hole or in a crevice in a rock wall. In this way, they're establishing a larder to be consumed during winter's lean days.

As for how they eat the nuts, a blue jay carries a peanut to a perch, then holds it between its toes as it batters the shell open with its beak. Then the bird will either peck the nuts inside into small pieces or eat each nut whole.

Pairing up

Q: Do cardinals keep the same mate for life?

A: A male and female cardinal pair typically remain together all year long, but if one dies, the survivor will search out another mate, so it's a case of "as long as we both shall live."

Super smart?

Q: I read somewhere that crows and jays have a unique part of their brains that gives them the ability to think and reason beyond what other birds can do. Are you familiar with this?

A: I haven't come across any information about crows and jays, both members of the highly intelligent corvid family, having a specialized part of the brain for reasoning. What is reported, over and over, is that these are very big-brained birds, capable of devising solutions to problems that would stymie other birds. Some researchers compare a crow's mental development to that of the average 4-year-old, which is pretty darn smart. Other researchers have called them "flying monkeys," in terms of intelligence.

Mixing it up

Q: I saw a bag of "critter food" at the hardware store, made up of corn and different kinds of seeds. Would birds, especially cardinals eat this, including the corn?

A: I'm always a bit leery of seed mixes (except those at wild bird stores), since these often are full of filler that birds either won't eat or that isn't very nutritious. Many such mixes contain a lot of red milo seed, and only Southwestern ground feeding birds seem to eat milo. Cracked corn is popular with ground-feeders, but it's pretty low in nutritional value. Cardinals will eat cracked corn but there are better things to offer them, such as black oil sunflower seeds or safflower seeds.

Lost nest?

Q: While cleaning out my wren houses a couple of weeks ago I found a nest with unhatched eggs. This is the first time I've ever seen this and wonder if it's common for wrens to leave a nest?

A: For some unknown reason, your wren pair abandoned their nest after their eggs were laid. Either something happened to one of the pair or other factors, like an insect infestation or the weather, discouraged them. It's not uncommon for wrens to abandon a nest and then find another spot for a new one. This species is known for the male of the pair establishing as many as five starter nests for the female to consider. She looks them over, then picks a site and builds her own nest. It's possible that the wrens whose eggs you found reverted to one of the earlier starter nests.

No naked birds

Q: My son asked me a question about birds and their feathers that I can't answer: Since all birds molt, why do we never find piles of feathers?

A: You won't find a bunch of all-yellow feathers from a goldfinch or a batch of red feathers from a cardinal, since songbirds don't molt all their feathers at once. To retain the ability to fly and be protected from the elements birds only change a few feathers at a time. They'll lose one feather from their right wing and one from the left wing, for example, and then molt no more wing feathers until replacement feathers grow in. The whole process occurs over several weeks.

You and your son probably have come across a single feather on the ground near your feeders, or on a trail in the woods, and that's all you'll ever find — unless you discover a spot where a hawk has stripped its bird prey, then you might find a pile of feathers. An exception to this is water birds like ducks and geese, which change all their flight feathers at once. They lose the ability to fly, so they hide out on lakes and wetlands where they feel safe until new feathers grow in.

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.