The National Aviary hopes to bring bird conservation to local back yards with its first-ever birdhouse design competition.

The Best Birdhouse in the ‘Burgh design-and-build contest is a way to let bird-lovers unleash their creativity while creating habitats for birds that face declining population because of human development, said Aviary spokesperson Laura Ellis.

“We thought it would be fun to get the community involved and highlight the importance of a backyard bird habitat,” Ellis said. “The more development we see, the less habitat there is.”

Participants in four categories will choose which type of bird to build for, such as the chickadee, purple martin, Eastern bluebird, wood duck, screech owl or others.

Meeting design specifications for each species is important because it ensures the target bird will be able to use the house, and that other species won’t take it over, said Aviary Director of Education Bob Mulvilhill.

All the birds in the competition are of some conservation concern, Mulvilhill said. These birds are “secondary cavity” nesters which means they must find a hole in a tree in which to nest.

Secondary cavities are in short supply, because the number of birds who excavate trees are limited, Mulvilhill said. Often birds like woodpeckers build their homes in dead or dying trees, which are frequently removed from parks and woodland by people.

Those factors along with expanding development leave the secondary cavity nesters with few options for homes.

“We’re having a negative impact on two kinds of birds, those who excavate [trees], and those who use them secondarily,” Mulvilhill said.

Enter man-made birdhouses. This kind of habitat has already seen much success with certain birds, like the Eastern bluebird. The survival of the bluebirds was in question 50 to 75 years ago, but thanks to conservationists’ efforts and plenty of birdhouses, the population is much more stable now, he said.

Not any birdhouse will work, though. If the entry hole for a bluebird box is larger than one and a half inches wide, starlings can fit and often will force the bluebirds out.

Box placement is also important, Mulvilhill said. Boxes for bluebirds and tree swallows have similar specifications, but bluebirds prefer open fields and tree swallows like to be near water.

“Each of them has their own space they can use,” he said.

Registration for all categories is due May 21, but birdhouse drop off days vary for each age group. For registration forms, information on categories and bird house specifications, visit www.aviary.org/birdhouse.

On July 16, the birdhouses will be auctioned off at the Night in the Tropics event and then, ideally, installed in their new owners’ back yards. Proceeds from the auction will benefit the National Aviary.