Inside Region 3
Midwest Region
Select this button stylePrint Friendly

Cathy Henry, manager of Port Louisa National Wildlife Refuge, releases a bald eagle fitted with a GPS unit/Courtesy of Trish Miller, West Virginia University.

Cathy Henry, manager of Port Louisa National Wildlife Refuge, releases a bald eagle fitted with a GPS unit/Courtesy of Trish Miller, West Virginia University.

Tracking Bald Eagles

Biologists at the Rock Island Ecological Services Field Office are working with researchers from West Virginia University to get a better understanding of how eagles move through the landscape and what risks they face.  The partners recently attached several GPS units to eagles wintering on the Mississippi River. These GPS-GSM telemetry units are the newest, highest quality and most cost-effective way to track eagles, using the cell tower network to download data. They also provide highly detailed information about movements and allow for customized duty cycles. The units will gather information on location, altitude, speed, heading, and fix quality. For the first nine days, we will collect data at 15-minute intervals from dawn to dusk. Every 10th day, the duty cycle will switch to 30 second intervals so that we can better understand specific flight behaviors. Such high frequency data provides exceptional insight into eagle flight behavior and allows detailed interpretation of the potential impacts of wind farms and power lines on eagles.

This data will be vitally important as eagle populations increase and wind energy development increases. Together, these increases may result in a greater potential for take, resulting in more application for take permits issued under the Bald and Golden Eagle Protection Act. Providing more accurate information about eagle movements across the landscape and during different times of the year is essential for the Service to make informed decisions during the permitting process. This project will contribute to a better understanding of how eagles move throughout the Midwestern landscape and what environmental conditions put them at greatest risk.

By Drew Becker

Last updated: April 10, 2014