Artificial On-Campus Nests offer Home to Eastern Bluebirds

Monday, March 21, 2011

Spring is here and the changing of the season means more feathery friends on the UWG campus.

Barbara Ballentine, assistant professor of behavioral ecology and evolution, is especially interested in the arrival of Eastern bluebirds. She is conducting a new research project to study their behavior and morphology.

Spring is here and the changing of the season means more feathery friends on the UWG campus.“With bluebirds, we can encourage new colonists by putting up these artificial nest cavities,” Ballentine said. “Eastern bluebirds need a cavity, but they don’t excavate them on their own. They find one that’s already there, either made by another bird, like a woodpecker, or one that’s naturally formed.”

Ballentine and her four student research assistants have constructed these artificial cavities around campus. The boxes are mounted to poles at a height of about five feet, with a predator guard underneath. The purpose of the project is to study the differences in aggression levels between bluebirds that live in rural and urban environments.

“Behaviorally, there are findings that bluebirds that live near people are more aggressive, both towards each other and towards predators,” Ballentine said. “They have personalities that make them more suited to an urban environment.”

The study will help Ballentine and her students discover whether this aggression stems from the urban environment itself, or whether the bluebirds are already aggressive.

UWG’s busy campus represents the urban environment, and the artificial cavities will encourage bluebirds to nest. However, the boxes may not deter other species from nesting in them.

Ballentine said the boxes may end up being home to brown-headed nut hatches and Carolina chickadees. Or worse: other unwanted species, such as European starlings or house sparrows.

“They are an introduced species,” Ballentine said. “They’re species that have been introduced to the area and would outcompete the Eastern bluebirds. In fact, they might kill the nestlings or the adults.”

If the boxes are successful, the bluebirds will be available for Ballentine and her team to study – not only for aggression levels, but also to monitor their plumage, color, weight, and bill and wing size.

Ballentine said urges students and faculty not to tamper with boxes, because it could also mean tampering with the project.

“It might be tempting to take a peek inside,” she said. “Luckily we haven’t had any problems so far, and there are no missing boxes.”