Q When I travel in the South, I encounter cardinals that seem to have no fear of people, but the cardinals at home are extremely skittish. Is there a difference between cardinals in the North and South, and could this be due to the Scandinavian influence around here?

A I had to chuckle at the thought of cardinals under the influence of our area's Scandinavian heritage. But no, I think what you're noticing is the "handout effect" -- I've seen the same thing at state parks in Florida, where people feed birds that visit the campgrounds. You're seeing cardinals that have become habituated to humans and expect a treat from any tall, two-legged creature. Most back-yard cardinals, North or South, are very wary of humans but are comfortable visiting feeders.

True blue Q Two questions about blue jays: (1) Do they stay mated for life, and (2) do they migrate in the fall?

A After a male and a female blue jay pair up, they tend to stay together as long as they both live (most birds live fairly short lives, so if one jay dies or disappears, the remaining bird will find another mate). We see blue jays year-round, but they may not always be the same birds. The jays in our area may shift down toward Iowa in the fall and are replaced by birds from farther north. Come spring, "our" jays return and the northern jays head back north.

Flame-flying 'deesQ I witnessed something unusual the other day: I was burning a big pile of wood and brush out at the farm and a flock of about 15 chickadees showed up and started flying across the fire. They would land on a bush on the other side, then fly over the flames again, almost close enough to singe their feathers. They kept this up for almost three hours and I'm wondering what they were doing.

A I wish I'd been there to see this interesting and unusual behavior on the part of those little birds. Chickadees are very smart and very curious, and the big, pulsating orange thing must have fascinated them. When they discovered that flying over it brought warmth on a cold day, it probably inspired them to make numerous flights, somehow instinctively keeping above the flames. And it may even have brought some fun into the lives of intrepid little birds that are pretty focused on survival in winter.

Mentor-less migration Q Do young birds need to migrate with adults the first time, so they know where to go?

A Astonishing as it may seem, millions and millions of young birds, some no more than a few months old, lift into the sky each autumn and head, all alone, to their species' winter home. And then they make it back in the spring to the area they left the previous autumn. Songbirds have migration information hard-wired into their brains, and they amend this internal map in later years with information based on their experiences. A few species, notably geese, cranes and swans, learn migration routes from their parents as the family flies together on their first migration.

Bad seed? Q I filled a feeder with seed I've had for years, but birds are staying away. Does seed get old?

A Seed does indeed get old and loses its appeal to birds. Seeds are full of oils and oils become rancid. As a rule, most seed will remain fresh for around six months, says Kraig Kelsey of Kelsey's Wild Bird Store in North Oaks, but if you have seed that's a year old, it's best to toss it in the trash and start over. At the end of winter, if you still have seed that you purchased the previous fall, it's time to visit the seed store.

Seed lasts longer if properly stored in a dry container out of direct sunlight. In winter, keep seed in a metal container outdoors or in an unheated garage, to avoid spoilage.

No mess Q What kind of seed doesn't cause any mess?

A Bird feeding can be a messy business, with birds accidentally knocking seeds out of feeders and dropping shells to the ground while they eat. Your best bet for keeping things tidy is to fill your feeder with hulled sunflower seeds. You need to take a little more care to keep these seed meats dry and fresh, since they lack a protective shell. Birds eat the entire thing, leaving no mess behind.

Sweet tooth 'dees Q In response to your recent answer, about chickadees drinking water out of hummingbird feeder ant moats, I just wanted to let you know that chickadees come to our feeders to drink both the water in the moat and the sugar water in the feeder.

A Thanks for letting me know this. I'd never seen chickadees drinking out of a hummingbird feeder, so this is a good insight to have.

Clever crows Q I remember hearing about crows dropping walnuts in the road so cars would drive over them and split them open. I want to try setting out a few walnuts to see what the crows will do. Do you think it will work?

A I believe the crows you're thinking of are Japanese crows. I haven't heard of similar behavior being documented in this country, although coastal crows drop mussels and clams onto rocks to split the shells open. Crows are very smart and willing to try just about anything to get at a food source. At the very least you'll have some fun with the walnut test, but keep in mind, squirrels will be watching, too.

Green herons Q I looked out one day and saw an odd bird perched on top of our feeder pole. We looked in some bird books, and identified it as a green heron. We don't live near water so is it possible that the heron was lost?

A Good for you, for taking the time to identify a bird seldom seen in back yards. Sounds as if the heron was on its way to its roost or was moving between its watery feeding sites. It may have noticed the activity at your feeders and dropped in to see what the other birds were doing -- birds are curious creatures.

Val Cunningham, a St. Paul nature writer, bird surveyor and field trip leader, can be reached at valwrites@comcast.net.