Beware insects: Summer is for the birds

Matt Gentry | The Roanoke Times New River Valley Bird Club Members Hannah Boehringer, 8, and Seth Boehringer, 10, check a bird house on the clubâ€'s Virginia Tech Corporate Research Center Bluebird trail Saturday. Over fifteen years trail data, up to eight hundred bluebirds have been raised and fledged from the trail'€™s boxes.

CLAYTOR LAKE – Pesky gnats, biting flies and annoying mosquitoes beware: beak-wielding insect eaters are in the air. Swooping and diving and dipping and soaring, flying insect catchers battle the summer bug season.
As a rule of beak, the number of insect-eating birds in an area is in proportion to the number of insects there to begin with. Birds could not eradicate their food source in an area and survive, unless they were far ranging species such as swallows and martins.

Purple martins, in fact, are North America’s largest swallow and have quite a following of their own.
At the lake in Pulaski County, purple martins chirp and sing as they fly over the water and around an apartment complex of martin houses, apartments and gourds.

Frank Shrewsbury, 84, hosts a colony of purple martin houses with up to 300 nest cavities on the lake shore near Lighthouse Bridge. This year he has about 50 birds taking up residence, more, he claims than anyone else on Claytor Lake.

An avid railroad man, Shrewsbury fell in love with purple martins in 1953, when he was first introduced to them in West Virginia.

“You can spot a purple martin a mile away” he said. “There’s a lot to know about them.”

Shrewsbury has been a member of The Purple Martin Society  since 1972, and a recipient of the society’s Purple Martin magazine.  He loves to have the birds at his home and has turned his interest into a hobby attracting them. He is in the process of opening 90 new rooms in two castles to replace some of the older martin houses he has. The first year he put up boxes he got martins to move in, he said.

Matt Gentry | The Roanoke Times Purple martins fly around Frank Shrewsbury'€™s martin houses at Claytor Lake on a recent Friday evening.

From his yearly notes Shrewsbury has deduced that his martins usually arrive on April 18 and leave about Aug. 10. “They fly all the way to Peru during the winter” he said.

“They’re the prettiest bird a flying I have ever seen,” he said. “You can spot them, as they sail, from other birds. They are fickle. They are a together bird; they don’t like having other birds around.

“They don’t eat off the ground. They eat mosquitoes and what they call dragon flies, and come in here and feed their babies,” he said.

As taken as Shrewsbury is with purple martins, he has a keen eye for a colony of barn swallows  that live under nearby Lighthouse Bridge. “They’re twice as pretty as a purple martin,” he said.

And Shrewsbury isn’t alone in his interest. Helping various bird species in their forays is a host of dedicated bird lovers and volunteers.

“The tree swallow feeds on flying insects such as gnats and mosquitoes, while the bluebird preys near the ground on caterpillars, crickets and other small insects,” said Bill Opengari of the New River Valley Bird Club. “A pair will likely tag team in attacking the swarms of insects in their nesting territories.”

Opengari, of Pearisburg, is the developer and coordinator of three New River Valley “Bluebird Trails” and has built and locally distributed approximately 1,500 bluebird boxes. The club’s trail at the Virginia Tech Corporate Research Center has been in existence for 18 years. Enlarged and expanded, two additional trails have been added, one at the YMCA’s Lambert Community Garden Farm on Bishop Road in Blacksburg and one at Glen Alton in Giles County.

In total there are 45 nest boxes on the three trails.

During nesting season, April through August, the trails are monitored weekly by volunteers that note the type of bird nest in the box and the number of eggs or young discovered. Old nests are cleaned out after the young birds have fledged.

Volunteers send their data to Opengari, who compiles the data weekly and keeps annual totals.

The Virginia Tech CRC trail averages about 50 to 60 bluebird fledges each year, and about 43 tree swallows from 12 of the nesting boxes. The records are sent annually to the Virginia Bluebird Society, which compiles records from counties throughout the state. Over the 15 years Opengari has compiled the CRC trail data, up to 800 bluebirds have been raised and fledged from trail boxes. Up to 5,000 bluebirds are fledged from similar birdhouse trails statewide.

“Bluebirds and tree swallows that utilize the trail boxes do consume enormous amounts of insects by feeding them to their hungry nestlings. People have often commented to me that there are often fewer ‘grass gnats’ in their yards when they have tree swallows nesting nearby,” Opengari said.

“Even the notorious, unloved starling is very beneficial,” he added, “as one of its primary foods is the ground larva of the Japanese beetle.”

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