By Bernheim
Spring migrations are now underway, occurring for many species of birds, bats, and some insects traveling north for the summer months. Bernheim’s golden eagles departed in mid-March, traveling 1700 miles north to nest on Canadian lakes that provide an abundant food source for their chicks. The pair has now reunited at their nesting site, beginning six months of cooperation that will hopefully result in the successful fledging of their offspring.
Harper, the male golden eagle, completed his migration to the nest site on April 12, 2020, a week later than Athena, the female golden eagle, who arrived on April 6. Their routes again followed separate paths, with Harper traveling through Minnesota west of Lake Superior and Athena traveling east of Lake Superior through Michigan. This nesting pair of golden eagles is the first to be documented to spend summer and winter together but use separate routes to migrate alone.
Athena got an early start, departing Bernheim on March 13, 2020. She wasted no time with rapid advancement towards her nesting grounds. Flying across the Great Lakes on March 22 at the Straits of Mackinac in Michigan, she entered the wild and frozen northern wilderness. The most recent data points showed her flying straight towards the nesting site, which was just 15 miles away. This suggests she arrived on the nesting grounds in northern Manitoba on April 6, which was,interestingly, the same date as she arrived in 2019. While in the wilderness of the Hudson Bay Lowlands, her GPS transmitter will likely not check in via cellular tower until fall migration. Based on what we learned in 2019, she has already have started repairing her two eyries (nests) and begun choosing a final site to lay her eggs.
Harper took his time leaving Bernheim and did not travel as quickly as Athena. His departure from Bernheim was several days after Athena, on March 17, 2020, after visiting neighboring large forest blocks in the days before leaving. This being the fourth year Harper’s migration was tracked, his course remained familiar. There were stopovers used in previous years, including the Hoosier National Forest near Lake Monroe and the Driftless Area of Wisconsin. He completed migration and arrived at the nest site on April 12. As with previous years, he checked the nest and then headed towards Churchill for his annual pilgrimage to the Hudson Bay. The reasons behind this journey remains a mystery, as the weather is incredibly cold today with wind chill at -5˚ as he flies into sustained winds of 17 mph or more.
The golden eagles are now reunited and nesting season has begun. Last year’s data showed an incredible amount of cooperation between the eagles as they worked together to build and repair their nest sites, incubate eggs, and feed their offspring. The landscape in northern Manitoba is still completely frozen, with wind chill temperatures not reaching 0˚ F for the next seven days. Snowpack blankets the ground, ice covers the lakes, and temperatures are the coldest they will experience for the year. To survive and raise their offspring the golden eagles must get an early start to build nests, lay eggs, and hatch chicks coinciding with the arrival of waterfowl and thawing of the lakes.
Despite the challenges of migration and extreme cold weather, this breeding pair of golden eagles is well equipped to succeed. Many mysteries of the Bernheim golden eagles have been solved by this research, and others still challenge our understanding of these birds. A second year of breeding season data is now being recorded, and if all goes well, will continue to shed light on the incredible lives of the Bernheim golden eagles.
