BANKING ON SWALLOWS

December 06, 2002 12:00 am
A nesting colony of 100 swallows will eat more than 50,000 mosquitoes a day. ().
A nesting colony of 100 swallows will eat more than 50,000 mosquitoes a day. ().

By Dick Mason

Observer Staff Writer

o outsiders it looks like a barren, useless bank of dirt.

Bird watchers, though, see it as a site of beauty.

The dirt cliff bank, two miles north of Hot Lake, is home to a colony of more than 100 pairs of nesting bank swallows each spring. The swallows nest in tunnels they dig out of the bank's sandy soil.

"This colony is one of the largest in the state,'' said Jim Ward, president of Friends of Ladd Marsh.

He noted that there have been years when at least 250 pairs of bank swallows make up the colony.

Bank swallows have been coming to the Ladd Marsh Wildlife Area since at least the 1960s. Each spring there is so much activity that it seems like a bee hive, Ward said.

The Grande Ronde Valley's avian bee hive is about to get busier.

The bank, about 150 yards long and 12 feet high and part of the Ladd Marsh Wildlife Area, is being renovated by the Oregon Department of Fish and Wildlife with help from Friends of Ladd Marsh.

The ODFW cleared loose dirt off of a large portion of the lower half of the 150-yard long bank on Wednesday.

The work, done with a bulldozer, doubled the number of potential nesting sites available, said Dave Larson, manager of the wildlife area.

The bank swallows, which spend the winter in Central and South America, like to nest in tunnels because they are protected from predators such as skunks, weasels and raccoons. They prefer to dig new tunnels each spring.

The bank is being renovated to provide more biological control for mosquitoes and other insect pests.

A single swallow will eat up to 500 mosquitoes a day. This means that a nesting colony of 100 swallows will eat more than 50,000 mosquitoes a day.

"You could say that swallows are a mosquito's worst nightmare,'' Ward said.

The effort to bring in more swallows at Ladd Marsh is timely because of concern about the spread of the West Nile virus in the United States. The virus is passed to people by mosquitoes.

Bank swallows are among six types found in the Grande Ronde Valley. The others are the barn swallow, tree swallow, cliff swallow, rough-winged swallow and violet-green swallow. Like the bank swallow, all feed primarily on flying insects.

Tree swallows and the violet-green swallows will accept artificial nest boxes, which means it is possible to also boost their population levels in the Grande Ronde Valley.

More than 250 swallow boxes have been put up at Ladd Marsh by the ODFW, the Grande Ronde Bird Club, Friends of Ladd Marsh, the Boy Scouts and others.

"Using a biological control for insects, such as providing boxes to attract pest- eating swallows, is certainly more environmentally friendly and less costly than chemical control,'' Ward said.

The Grande Ronde Bird Club and the Friends of Ladd Marsh will construct more swallow boxes during a bird box building day early next year. Swallow boxes will be available for no charge.

Information on how to build swallow boxes will soon be available on the internet at www.easternoregon.net/ladd/, which is the Friends of Ladd Marsh Web site. The site also has information on birds, plants and mammals at Ladd Marsh.