Fine Feathered Friends Courted
By Carla Garnett
Photos by Bill Branson
On the Front Page...
Wanted: Residents to occupy a couple dozen brand new homes on the NIH campus.
Cost to rent: Really cheep (sorry), although applicants must be willing to work in exchange for housing.
The offer is real, but it is not an equal housing opportunity, according to Lynn Mueller, chief of NIH grounds maintenance and landscaping. Only birds (and small brown bats) need apply, and then only specific types of birds Eastern bluebirds, chickadees, tufted titmice, nuthatches, warblers, Carolina and house wrens, tree swallows, and several kinds of woodpeckers.
About 30 birdhouses, three roosting houses and a couple of bat houses will be installed across the campus in the coming weeks to help attract and keep more native song birds as permanent residents on campus, Mueller says. The project is not just for its aesthetic value to the grounds, either.
"We want to encourage more birds and bats to help us naturally control campus insect pests including mosquitoes," he explains. "We don't want to spray insecticides on campus, so this is a natural solution to reducing many insect pests."
In addition to possibly controlling the mosquito population at NIH more of a concern within the last year due to reports of the West Nile Virus with mosquitoes as the vector the project to lure more birds here has other practical advantages as well.
"Unfortunately, our required tree maintenance work eliminates a lot of habitat," Mueller says. "Our tree preservation policy requires us to specify whether we're removing trees during nesting season or whether birds may be using the tree as a roost. In most cases, we leave dead trees standing as long as possible if they contain nest cavities or roosts, but we hope these houses will offer an attractive alternative for the birds when we have to take down the rotting trees. That's why we're putting up several houses for woodpeckers. They naturally inspect and remove many destructive insects from our trees every day."
After consulting with the National Audubon Society and other organizations interested in preserving and enhancing urban wildlife habitats, Mueller purchased all the birdhouses and two bathouses available from local wildlife stores. The unpainted cedar structures are mounted either on poles in relatively open lawn areas around NIH's perimeter or on trees, depending on what species groundskeepers want to attract. Campus pedestrians may come across several of the houses while strolling on footpaths near the front lawn of the Stone House, on the southeast grounds of the National Library of Medicine or along Center Drive near the Children's Inn.
A bird fancier himself (with the Boy Scout merit badge to prove it), Mueller has researched the likes and dislikes of native fowl and adjusted accommodations accordingly. Some of the houses have been installed so that the 1 ½-inch entrance holes face east, because bluebirds and tree swallows tend to appreciate the warmth of the morning sun. The houses sit about 5 or 6 feet off the ground to simulate fence posts. Other houses are placed from 6 to 20 feet up along a tree trunk to attract woodland cavity nesting birds like chickadees, titmice, nuthatches and wrens. No birdseed will be offered near the houses; that may cause the residents to become dependent, and it would, after all, defeat the purpose of attracting insect-eaters.
If all goes according to plan, the houses will be in place by Mar. 1, which is when male birds tend to come searching for territories. Houses that will occupy the same general area are installed a few dozen yards apart to prevent turf-fighting by the males.
"If we set the houses too close together," Mueller says, "the males may just fight each other over territory instead of courting females." If successful, more houses will be set out next winter.
Predator birds such as crows, starlings and sparrows already plentiful on campus are not welcome in the new houses. "They're destructive by nature," he explains. "They'll tear up the nests and scare away the beneficial birds we're hoping to attract." In some cases, plastic and metal plates have been placed around the holes in the houses to discourage larger birds and other predators such as squirrels and raccoons from gnawing the wood to enlarge entrances to the houses.
Just as all birds are not the same, mosquitoes also come in different kinds. That's why Mueller also bought a couple of bathouses. "There are daytime and nighttime mosquitoes," he notes, pragmatically. "Bats can eat their weight in mosquitoes per night. Although bats are harder to attract, we hope we can start a few colonies to take care of the evening insects. There's no better natural way to eliminate mosquitoes."
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