Q: Why do so many kinds of woodpeckers have black and white feathers?

A: That's an excellent question, and it's true that downy, hairy and red-bellied woodpeckers have striking black and white patterns on their backs and wings. This is called disruptive coloration, and the contrasting colors help hide the birds from predators. Even though the patterns make the woodpeckers stand out for us, they break up the birds' shape and outline as they cling to tree trunks or limbs. This provides a bit of protection from a predator like a raptor as it zips through the neighborhood. It's similar to the way a tiger's stripes help to obscure it in tall grass, and a frog's skin pattern helps it to hide in a marsh.

Woodpecker attacks

Q: I've lived in my home for 19 years, and suddenly my garage is being attacked by woodpeckers. Do you have any suggestions for preventing further damage?

A: Sorry to learn that woodpeckers are drilling holes in the wood on your garage, but be assured that there are steps you can take to deter these birds. The Cornell Lab of Ornithology has studied this problem for years and has posted excellent advice at: birds.cornell.edu/wp_about. Another good source is a Minnesota DNR site: dnr.state.mn.us/livingwith_wildlife/woodpeckers/index.html. The photos you sent indicate that the woodpeckers are drilling in search of insects. One suggestion to go along with the online tips: Set up a suet feeder and a feeder filled with shelled peanuts some distance from the garage, and these should keep the woodpeckers well fed, thus less interested in probing into your garage.

Banning ducks

Q: I live in a condo building, and enjoy the mallard that nests each year in the big flowerpot near the pond out back. But now our condo board is putting mothballs in the pot to discourage the duck because they feel she will attract Canada geese. Is there any validity to this?

A: I'm sorry to hear that your condo board is trying to discourage a harmless duck from nesting. I've never heard of Canada geese being attracted to a small body of water by ducks. In fact, hunting sites on the Internet suggest that the opposite occurs — some duck hunters set out goose decoys to attract ducks. I hope you can persuade your board that allowing a mallard to nest near the pond will almost surely not attract a flock of geese. If geese do show up, it will be the grassy area around the pond that attracts them. If your condo rules allow residents to have dogs, an active, yappy dog makes a great goose deterrent.

Late bloomer

Q: I looked out the window today [late October] to see a juvenile cardinal following a male (the dad, I presume) while making those insistent "feed me" cries. I wondered if the parent bird was still feeding the younger bird.

A: That was fairly late in the year for a young bird to still be reliant on a parent for food. But cardinals nest twice during the breeding season, and this might have been a young bird from the second nest, old enough to fend for itself but still a bit too young to want to set out on its own. The young cardinal was probably hoping that its begging calls would produce an easy meal.

Swamp pumper

Q: Many years ago my parents and I lived near a river in northern Minnesota where I frequently saw bitterns on the marshy shoreline and heard their "pump" sounds. I still live in this cabin but haven't heard a "slough pumper" in years. Any thoughts on their apparent absence?

A: Now that you mention it, I haven't seen or heard one of these elusive herons in years, either. Neither the Minnesota Department of Natural Resources or the U.S. Fish and Wildlife Service lists the bird as endangered or threatened.

Anecdotally, I've heard others say they haven't seen a bittern in a long time, and this may be due to habitat issues. Bitterns spend their time hiding in reeds along a shoreline, and these habitats are under siege as land is drained for farming, housing and commercial development. It's possible that there have been changes in the habitat around your northern cabin — a sad thing, because these birds and their booming calls (allaboutbirds.org/guide/American_Bittern/sounds) are an integral part of marshes and wetlands.

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