When Sarah Whitney first began working with researchers to study local tree swallows, the prospect of having to hold a bird and tiny fledglings was intimidating.
But now the senior environmental science major looks like a pro as she weighs and measures the birds and their chicks.
“When the birds are being handled, they are sometimes calmer than expected, while others are particularly squirmish and try to fly away.” Whitney says, “Something that I appreciated about the project was being able to gain experience in bird handling and gaining an appreciation for the tree swallows, because they are truly beautiful birds.”
This summer, along with students and recent graduates from UTC and other universities, Whitney is working with a team of researchers from Cornell University’s Lab of Ornithology, examining tree swallows in a nationwide study.
Numbered nesting boxes on poles are scattered throughout Chattanooga—along the Riverwalk, at Greenway Farms, the Chickamauga Marina, even the local Volkswagen plant. The nesting boxes are homes to tree swallows, a migratory bird that researchers are studying to better understand how the birds’ biology responds to environmental stressors.
The UTC students begin their work at 7 a.m., making their way quickly to each nesting box and placing a hand over the entrance, hoping to catch the adult birds still inside.
“Sometimes we have to wait a while and stalk them until they fly in,” says Laura Marsh, UTC alumna and adjunct professor in biology, geology and environmental science.
They measure the adults’ heads, bills and wing lengths, record their weight, and band them for identification and to track how frequently they feed their young. Blood samples also are taken. When the chicks are 12 days old, they are banded and measurements and blood samples are taken.
“This project is so important because we are studying how birds respond to environmental stressors, which are going to increase with climate change and other human pressures on natural systems,” Marsh says.
“I love studying nature and, by collecting these data, I feel I am contributing a small piece to a bigger overall puzzle of the complexities of our natural world,” she adds.
Lead researchers Cedric Zimmer and Maren Vitousek from Cornell Lab of Ornithology are trying to determine how each bird deals with environmental stress and whether they pass those traits on to their chicks.
Tree swallows are ideal birds for research like this, says Dr. David Aborn, associate professor in biology, geology and environmental science. Even with all the handling, measuring, leg bands and blood-sucking needles, they aren’t fazed.
“They’re very tolerant,” he says.
Summertime and the living is easy—for swallows in Chattanooga, that is.
Local swallows have the shortest distance to travel during migration; they spend the winter closer to the equator—Florida, Louisiana, Central America—then fly to their summer nesting grounds spanning from the mid-South to Alaska. Locally, their mating season—March-July—is so long they sometimes have two broods of chicks in one year.
For the tree swallows who breed further north, longer migrations, colder and shorter breeding seasons make life more stressful.
Researchers are studying birds from here to Alaska through a multi-year grant from the National Science Foundation. Their work started in Alaska last year and, this summer, the research began in Chattanooga and will continue in Wyoming later in the season.
Chattanooga is the southernmost research site but, until a few years ago, there weren’t enough tree swallows in the area to study, Aborn says. The birds weren’t breeding here. Around 2005, a group of retirees started installing nesting boxes in the birds’ favorite breeding grounds: open fields near bodies of water.
“If you build them, they will come,” Aborn explains, “It wasn’t until about 2012 that the population of tree swallows grew large enough to collect a workable amount of data.”
Hands-on experience, networking and a deeper dive into bird research are just some of the benefits for students participating in the study, he says.
“These students are getting to work with a research associate from one of the top ornithological research institutions in the country and getting to work with and know students from other parts of the country with different backgrounds and different experience levels,” Aborn says.