Mosquitoes don't go to the swifts

If birds held their own summer Olympics, medals for aerial artistry would go to swallows and swifts.

These birds chase flying insects on the wing, ranging continuously through the air on the long days of summer. Their superb flying skills allow them to swoop and dive, bank and circle, swiftly changing direction in pursuit of a meal.

At this time of year, insects make up a large part of the diet of most birds. But each species has its own foraging style. Stolid robins drop heavily to the ground to listen for worms, bluebirds perch patiently while waiting for a tasty beetle to stroll by. Though they're good at getting dinner, these birds lack the sheer showmanship of swallows and swifts, whose natural element is the sky.

Mosquito myth

There's a persistent myth that swallows and swifts (including purple martins, our largest swallow) help control mosquitoes. No matter how often martin house manufacturers tout this, studies show that mosquitoes make up an insignificant portion of their diets.

Unlike nighthawks, swifts and swallows don't simply open their beaks and vacuum up swarms of insects. They make a meal one insect at a time. Instead of going after mosquitoes, they focus on larger prey such as dragonflies, butterflies, moths, beetles, bees, wasps and flies.

If you buy a purple martin house as a way to keep mosquitoes under control, you'll be disappointed. But if your goal is to provide a place for avian athletes, you'll be pleased.

Swallows and swifts could be finalists in another Olympic category, as well, the endurance trials. These birds cover a lot of ground to feed themselves and their offspring. It's estimated that a tree swallow may cover hundreds of miles daily as it continually ranges over its small feeding territory.

We can make life easier for these aerial foragers if we retire the zapper lights that electrocute large numbers of flying insects. Bug zappers have little effect on mosquito populations but are lethal to many kinds of beneficial insects.

"Birds are stressed enough," said John Moriarty, natural resources manager for Ramsey County Parks. "Anything that takes away more of their prey is a hardship."

The next time you're walking along a lakeshore, golf course or open parkland, keep an eye out for small, extremely active birds skimming the water or chittering overhead. They're nature's flying athletes, chasing down their next meal.