Researchers at the Cornell Laboratory of Ornithology and the North American Bluebird Society (NABS) are asking bird-lovers to log on to http://birds.cornell.edu and put their birdhouses on the map for the first-ever Great North American Bluebird Count, May 14-17.

This four-day, Internet-based count is part of Birdhouse Online, a new web site cosponsored by the Cornell Lab's Nest Box Network and NABS, with support from the National Science Foundation. Since March 1, 1999, Birdhouse Online has been collecting information from across the continent about cavity-nesting birds (birds that nest in natural holes in trees and in constructed nest boxes) such as chickadees, swallows, and bluebirds. The site features maps for each species, regularly updated, with numbers and any indications of breeding, such as nesting materials, eggs and young.

"There are thousands of nest boxes out there," says AndrŽ Dhondt, director of the Cornell Lab's Bird Population Studies program. "We need to know what's going on inside each one. We can use what we learn about one species of cavity-nesting bird to better understand and protect all cavity-nesters."

But, adds Dhondt, a nestbox is not a requirement for participating in the Internet count. Anyone who sees bluebirds, kestrels, or other cavity-nesting species is invited to visit the web site and enter sightings.

The bluebird count was developed to focus the nation's attention on cavity-nesting birds for one weekend of the year, at a time when birds in the South are a good way into nesting and birds farther north are just starting. Although the count encourages participants to submit sightings of more than 30 species, the Cornell Lab and NABS named the count for the bluebird because it is a symbol of conservation success.

Bluebirds suffered serious population declines during the early part of the 20th century. Bluebirds cannot excavate their own nest holes and must rely on pre-existing cavities in dead or dying trees, in field and orchard habitats. Their populations plummeted because of development and competition with non-native, cavity-nesting species, such as house sparrows and European starlings. Pesticides also are believed to have had an adverse effect on bluebird nesting success.

Fortunately, bluebirds will use nest boxes, or birdhouses, as they are more commonly called. Beginning in the 1960s, birdlovers, concerned about how few bluebirds they were seeing began putting up nest boxes around their yards and farms. Thanks to their efforts, these birds -- to many, "the symbol of happiness" -- are again coloring the landscape with their presence.

Not all species are faring so well. The small, colorful falcons called American kestrels, for example, are showing declines in some parts of the country. The bluebird count, it is hoped, will collect data that will benefit these regal birds.

To get a "bird's eye view" of what goes on inside nest boxes, Birdhouse Online is featuring Nest Box Cam, which shows video images taken from inside two nest boxes in North Carolina and South Carolina.

The bluebird count is an engaging family activity, says education coordinator Colleen DeLong, and to help involve children in the event, Birdhouse Online is featuring a coloring contest. Children of all ages are invited to send in their completed pictures of cavity-nesting birds, which can be printed out from the web site. Their artwork might be displayed at the site's Picture Gallery, and each lucky winner, chosen by a random drawing, will receive a birdhouse.

The site also features information on the different cavity-nesting species, tips for building or choosing a good nest box, and more. Everyone is encouraged to return to the site often to view nesting activity as the breeding season progresses throughout the continent.

GNABC and Birdhouse Online "provide an engaging, interactive resource for citizen scientists of all ages," says Dean Sheldon, Jr., of the NABS. "We encourage everyone to put their birdhouse on the map. It's fun, and it will give us a better understanding of bluebirds and other cavity-nesting birds -- a great way to make a difference for these birds we all enjoy so much."

For more information, contact the Cornell Lab/GNABC, 159 Sapsucker Woods Rd., Ithaca, NY 14850 at (800) 843-BIRD (2473), or cornellbirds@cornell.edu.

The Cornell Lab of Ornithology is a membership institute whose mission is to interpret and conserve the Earth's biological diversity through education, research, and citizen science focused on birds. The NABS is a non-profit conservation, education, and research organization promoting the recovery of bluebirds and other native cavity-nesting bird species.