Some people have the mistaken idea that birds are dirty, vermin-ridden creatures, a view that's very wide of the mark. I can't quite fathom where this odd notion comes from, unless it's based on the fact that birds spend their lives in the outdoors.

The truth is that birds are highly groomed, taking top marks for personal hygiene in the animal kingdom. They work very hard on self-maintenance and it could be said that unless illness or injury impairs their ability to preen, birds are just about as clean as cats.

This isn't a matter of personal preference: Birds keep their feathers and beaks in good condition because doing so can make the difference between life and death. They're hard-wired to spend time grooming feathers and honing beaks on a daily basis, and they do so several times each day.

Feathers are a miraculous body covering, keeping rain out and warmth in, protecting from sunlight and most parasites, and are the key to the ability to fly. But they require steady work to comb, straighten and zip each feather's tiny structures together.

If you've watched a bird sitting on a branch after visiting your birdbath, you've seen how time-consuming this can be. An individual wing feather may have 1 million tiny, interlocking elements, and all must be realigned on a regular basis. Run a finger along a dropped feather's vane and microscopic hooks detach from each other, making the feather ragged. Run your fingers back up and the hooks re-engage and smooth out. This is what a bird is doing as it pulls each feather through its beak, closing any gaps that might interfere with flight or weatherproofing.

As part of this grooming process, they nibble or pluck any dirt away and pull out any parasites they find. In warmer weather, many birds will "sunbathe" on the ground, with wings outstretched. This seems to cause any parasites to move around, making it easier for a bird to pluck them out.

"External parasites are a natural occurrence in wild birds, hence they spend a good amount of time preening their feathers," says Leslie Reed, senior veterinarian and director of veterinary education at the Wildlife Rehabilitation Center of Minnesota in Roseville.

Most birds finish a preening session by using their beak to remove waxy oil from a preen gland near the tail and spread it on their feathers. This keeps feathers flexible and may prevent the growth of harmful bacteria and fungi.

Beaks, too, require upkeep, albeit a less time-consuming task. Since they continue growing throughout a bird's life, beaks must be honed on a regular basis. After eating, a bird lands on a branch, arbor or other structure, and then swipes its beak from side to side against the wood or metal. This wears down the new growth and evens out any chips or tiny breaks, normal wear and tear for such a heavily used body part.

"The condition of the beak is crucial to a bird's health, not only for effective hunting and manipulation and consumption of food, but also for the preening process," notes Reed.

There are other ways birds groom themselves, and one of the more intriguing is called "anting": A bird may either pluck ants from the ground to place on its feathers, or squat down on an anthill and allow ants to crawl over feathers. Odd as this sounds, scientists speculate that the ants' formic acid secretions kill any parasites. Some species, particularly house sparrows, take dust baths, flapping around in dry soil to dislodge any mites and absorb excess preen oil.

Just about the only time that adult birds let themselves go a bit is during nesting season. They race around from dawn to dusk feeding their offspring, leaving little time for a good preen. By the time their offspring fledge, parents may look a bit ragged, but they soon groom themselves back to their sleek look.

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