Under the watchful eye of one of the adult eagles, Alcoa's two eaglets temporarily were removed from their nest Monday to become part of a migration study.

With one of the parent eagles circling the sky above, Dr. Trish Miller, a wildlife biologist at West Virginia University, was raised 80 feet into the air on a boom with Duane Smith, an Alcoa electrician and president of IBEW 1379, at the controls. After the boom was maneuvered to reach the nest, Miller carefully retrieved the two young birds that hatched more than seven weeks ago on Alcoa Davenport Works' property in Riverdale.

While still above ground, Miller placed tiny leather hoods over each birds' head and beak to protect the handlers and eaglets. The pair then were carefully placed into cloth bags and brought down to the ground to be banded and equipped with a special GPS transmitter.

''They're both a little stressed out because, obviously, we took them out of their homes," Miller told the small group of fellow researchers and Alcoa employees. "But the good thing about chicks is you can just let them sit there."

The birds, which hatched in early April, are still a few weeks away from learning to fly, Alcoa spokesman John Riches said.

The Alcoa eagles now are among more than 25 eagles under study as part of the Midwest Bald Eagle Project, which plans to trap as many as 50 eagles in order to put the GPS/GMS transmitters on each bird.

"The whole point of the project has been there have been issues with eagles getting killed in wind farms, and we want to find out when and why it is happening," said Drew Becker, a fish and wildlife biologist with the U.S. Fish & Wildlife Service, which is partnering on the project now in its third year. "We're trying to figure out ways to mitigate that."

Becker said the project is looking at birds across Iowa and Illinois, but they migrate from all over the Midwest and as far away as northern Canada. "These are river eagles, but we also are going to get birds out in the farmlands of Iowa and Illinois."

With the birds safely on the ground, Miller took several measurements of their beaks and legs, pulled a feather sample and drew a small sample of blood from each — explaining each step to the 10 volunteers and onlookers.

"We're testing for heavy metals. We have students who are doing a project on lead contamination," she said, adding that the blood test also would confirm the sex of the bird, though from their size she believes there is one of each sex. Lead likely comes from the animals they eat, including deer or other animals that have been shot or fish with lead sinkers.

The most time-consuming task was attaching the transmitter, a GPS-GSM telemetry unit, to the bird's body. Using Teflon ribbon, a non-abrasive material, she secured the transmitter like a backpack, using the ribbon to create a harness. "Body feathers help the transmitter stay in place," she said.

"We put them on to stay on. It's too dangerous if they come off," she said, adding it could become a flight hazard. "At this point, they should be full-grown body-wise," she said, adding that all the growth now will be in feathers and building up muscles.

The tiny transmitter will allow researchers to follow the migration path of the eaglets, which now are known to fans of Alcoa's Eaglecam website as Star and Sky. Some transmitters have remained working as long as five years.

According to Becker, the transmitter weighs 60 grams, is solar-powered and contains a GPS that not only will track where the bird flies to but its speed and altitude.

Each bird also received a silver band around its leg that included an identifying number. Riches had the privilege of banding the first eagle. He has led Alcoa's Eaglecam, a web camera positioned over the nest streaming video to a website, since it began in 2010.

As populations of bald eagles have increased so have their conflicts with human activities, mainly wind turbines, communication towers and other structures. 

"One of the central questions is if you know the Mississippi River concentrates eagles, at what times and what conditions are they going off river to feed?" Miller said. She added that it is when they migrate upland that eagles tend to get killed by wind towers. "They are not programmed to see a wind turbine spinning in the sky." 

While most of the birds being studied are adults, she said, "we'd miss a whole part of their life if we only studied adults." 

In fact, Becker said juvenile birds have the highest rate of colliding with human structures.

When the birds begin to take flight and data comes in from all the tagged birds, Becker said they will have information on their migration paths. "So when a transmission line or a wind farm (is locating), they can try to intelligently site these structures."

Riches said the study is a "win-win" for everyone. "Environment is a key issue for us here, a priority here in the Quad-Cities for a long time." He added Alcoa is pleased "for them to be able to include our eagles in their project."