Q How often should I clean out my bird feeders?

A I'm so glad you asked this question because it touches on one of the most important aspects of feeding birds -- the need to keep feeders and food clean. If birds could talk, I suspect they'd say something like this:

"We're really grateful for the food you put out for us and don't mean to be ingrates but ... ahem ... sometimes things aren't as fresh as they could be. A couple of times, after a rain, the seed has gotten damp, and this can make us sick. Sometimes the nectar tastes a little off, too. If people would clean out the feeders more often, it would be better for us birds."

There you have it, straight from the birds' beaks. All of us who feed birds want to do the best by them, but we hear little about one of the most important aspects of feeding birds -- feeder maintenance and sanitation. For some reason, the bird-feeding industry doesn't talk about this much, but it's of paramount importance.

Feeders need to be cleaned on a regular basis, and moldy or insect-infested seed or bacteria-contaminated nectar must be tossed. Otherwise, birds may be sickened or killed by diseases such as salmonella or, in the case of hummingbirds, fungal infections. We don't see sick or dying birds because they instinctively hide away when they feel ill, but wet and moldy food and feeders can kill birds.

Every two weeks during the summer, and half as often in winter, inspect plastic feeders for any cracked or broken edges that could cut bird feet or beaks. Watch wood feeders for damaged spots that could cause splinters. While you have the feeder down, pour out the seed (if it's clean, you can save it to refill the feeder later) and give it a thorough wash and rinse. Experts recommend submerging just-cleaned feeders in a 9-to-1 water-to-bleach solution, then thoroughly rinsing them. This should kill most of the pathogens that build up.

Hummingbird feeders need slightly different treatment: Don't use any detergent or bleach, because the birds can sense these even after many rinses and will avoid such feeders. A thorough rinse should do the job. If you have a large, barrel-type feeder at a cabin, set it out only while you're in residence; otherwise bacteria can build up and sicken the little birds.

Another major hazard for hygienic bird feeding is moisture. I'm not going overboard by advising that you check feeders after every rainstorm and snowfall. Moisture can enter most feeders and begin to spoil the seed, especially the shelled kind, such as sunflower pieces. If you find clumps in the seed, pour it out, toss it in the trash and start fresh. I check my feeders after any precipitation and often find that most of it has remained dry. Dry seed can be saved, but the clumping stuff goes.

And lastly, don't ignore the birdbath. A reliable source of water brings in droves of birds to drink and bathe nearly every month of the year. But please get in the habit of spraying out the birdbath bowl on a daily basis before refilling it with fresh water. After only a few hours a bath can be cloudy with feather dust.

Do these things, which shouldn't add more than a half-hour a week to your feeding regimen, and you can rest easy knowing you're offering a clean, healthy environment for your wonderful birds.

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