Officials said they have had some success using hoses and clappers to keep migratory birds away from the Oklahoma City National Memorial.

Kevin Grant, director of the state Agriculture, Food and Forestry Department's Wildlife Services Division, and Mark Bays, an urban forester with the Agriculture Department, said the purple martins, a large variety of swallows, are currently in the region on their way to South America for the winter, and a few weeks ago they began congregating at the memorial and other downtown locations, The Oklahoman reported Thursday.

"They are a beloved bird in Oklahoma," Grant said. "They're very beneficial. They eat insects. They just mass themselves in large numbers at the wrong place at the wrong time."

The men said they turned to clappers and water hoses to keep the birds away from the memorial out of respect for the site.

"We want to preserve and protect that small little place that means so much to people," Bays said.

They said there has been a reduction in the amount of birds gathering since they began using the technique.

"It won't be but a few weeks before these birds are headed south anyway," Grant said. "This is kind of an overgeneralization, but in the summertime we have the bug eaters here. ... In the winter, when you put out your birdfeeder, you've got the seed eaters."