By Andrew Berry
We are pleased to announce that Athena, the female golden eagle tracked from Bernheim Forest, has checked in on her fall migration. After spending the previous six months in northern Manitoba on the Hudson Bay lowlands. She departed on October 19, 2021 to begin her nearly 1700-mile migration south. The male golden eagle, Harper, has not checked in since last spring when he arrived in Churchill.
This year’s fall migration had an unexpected twist when the normal route for Athena shifted, possibly due to heavy winds. On October 21, her direction turned south, a deviation from her normal southeast route towards Michigan. This pushed her directly towards Thunder Bay and onto the west side of Lake Superior. This was the first time in six migrations (spring 2019-fall 2021) that she flew west of Lake Superior, with all other tracked routes using Mackinac Straits in Michigan to the east of Lake Superior.
For golden eagles in the Midwest, it seems that Lake Superior presents a major obstacle for navigation, since they usually avoid with long journeys over open water. Most golden eagles pass through several distinct corridors that move through or around the Great Lakes. While this is the first time Athena has been documented flying west of Lake Superior over Duluth, Minnesota, her mate Harper has used this track every year since 2015. It is possible she has traveled this way before and is familiar with both routes around Lake Superior.
Athena was found to have used Harper’s familiar stopovers in the Driftless Area of Wisconsin. The Driftless Area is a rugged and sparsely populated region that offers locations to rest, hunt, and prepare for the long journey over the Midwest. During the final leg of the migration, the golden eagles cross midwestern agricultural lands where protected stopovers and food sources are nearly absent. We have seen Harper stopping in the same sections of Wisconsin that Athena used this fall, further demonstrating how important this area is for migrating birds.
At her last check in on November 21, 2021, we noted that Athena began a sharp ascent traveling as high as 3600-foot altitude (.65 miles above earth’s surface) as she approaches the Chicago region. We expect her southern journey to now move rapidly towards Bernheim, where she should arrive sometime before December. While traveling through Ontario on October 31, she reached her top altitude so far of 1356 meters, or 4448 feet. Taking the elevation of the land into calculation, you can see Athena is again flying at around 3600 foot, or .65 miles, above the earth’s surface.
Harper’s location remains unknown, and it is possible he may still be in Canada headed south. Other possibilities include that he did not make it through the summer in Canada, as he is known to be at least 12 years old, but likely older. Another possibility is that his location has not allowed for uploading his data due to inadequate coverage, or possibly tracker malfunction. He last checked in April 11, where he appeared to be hunting or scavenging late winter wildlife on frozen marshlands near Churchill, Manitoba.
A special thanks to Beckham Bird Club, Cellular Tracking Technologies, Conservation Science Global Inc., and all the supporters of Birds of Bernheim that make the golden eagle project possible. The support from Bernheim’s members, volunteers, staff, and donors are what allow us to protect wildlife and steward their habitats. Stay tuned as we follow Athena on her journey south and keep a lookout for Harper.