Helping Bald Eagles Soar

Joining the UMD team on a long-term project researching the health of the bald eagle requires more than a passion for the environment, or to save the majestic bird. It also helps if the graduate students working in Professor William Bowerman's outdoor lab can climb trees. 

"There is nothing quite like scaling a 70-foot tree with nothing below you, climbing up to the nest and poking your head in to see a young eagle looking back at you," says Rachel Eberius ’15, who’ll graduate in December with a master’s of science in ecosystem health and natural resource management. She’s the latest in a string of nearly 50 students to emerge from the project.

The first in that line of researchers is Bowerman himself, who has run the 32-year-old UMD program since its start, and today also serves as chair of the Department of Environmental Science and Technology.

He also runs the 57-year old Michigan Bald Eagle Biosentinel Project, which focuses on the effect toxins like DDT and flame retardants have had on the health and survival of the only eagle species unique to the continent. Bowerman’s decades of work and the policies that he helped influence have been key to keeping America’s national symbol patrolling our skies.

Scientists estimate that in the 1700s, a half-million bald eagles lived in the territory of the present-day United States. Two hundred years later, the number is thought to have dipped as low as 500 nesting pairs.

“When I first started this work in the ‘80s, we didn’t know if the bald eagle would survive,” Bowerman said.

Today, the number of eagles exceeds 10,000 nesting pairs in North America, and the species has been taken off the endangered list, although it still faces chemical threats.

Recent research from Bowerman, his team, and colleagues at the University of Indiana shows that toxic flame retardants banned 14 years ago still exist in the bodies of bald eagles and could become even more dangerous when metabolized into other compounds.

Located high in the food chain and thus exposed to a wide variety of toxins, bald eagles are a "sentinel species" that provide warnings about environmental dangers to humans and other organisms, Bowerman says. Studies have found that, among other things, exposure to flame retardants may cause genetic damage.

Researchers can use chemicals in the blood or feathers of eagles to determine toxin concentrations in the surrounding aquatic ecosystems and waterways, since eagles constantly consume fish and aquatic wildlife.

“Bald eagles are a great indicator for overall ecosystem health,” explains Bowerman. “On shorelines and in the Great Lakes, contaminants in the eagles were six times greater than for (eagles living at) the land sites.” 

His eagle program recently became part of a unique educational experience for Scouts interested in studying biological and environmental sciences in college, as one of only six available fellowships in the world for the National Eagle Scout Association’s World Explorers Program.

For Bowerman’s grad students, it’s long been a defining experience. They spend eight-and-a-half weeks each year “living out of a duffle bag and on the go” over the summer in Michigan tracking, banding, and gathering samples and data from eagles, Eberius said. It provides a good taste of what it’s like to do on-the-fly field research.

“You do everything—it’s a great leadership role,” says Eberius. “During the school year, you don’t necessarily have a ton of say in what goes on in the classroom, but in the eagle program, you are in charge. You are giving the orders, talking to the public, hiring people, running lab samples, and in the field or in trees. It wasn’t what I expected to get out of grad school, but I wouldn’t have it any other way.” 

Eberius’s Instagram account, @roamwithrae, documents the joys of her work high in the trees. 

“Sometimes you’ll be climbing and everything hurts and you are like why do I do this?” she said. “But then you get to the nest, and you see the baby eagle, and the views are awesome. Then you go, oh yeah, this is why.” 

See the team in action in Michigan here: https://youtu.be/lLEM9tnRsd4