Dozens of volunteers spend their spring and fall in Kananaskis Country peering through binoculars and other telescopic lenses, searching the sky for migrating eagles.
The migration route runs north from the United States along the Rocky Mountains, all the way up to the Yukon. It was discovered by chance in 1992 by Des Allen and Peter Sherrington. It became known as the ‘Eagle Highway.’
Strong updrafts are created in the area by the mountains and prevailing wind that mean the eagles don’t have to expend much energy to travel vast distances.
Cliff Hansen is a 15-year volunteer and now sits on the board for the Rocky Mountain Eagle Research Foundation (RMERF). The 86-year-old has counted a lot of eagles in his time.
“In the early days we’d count 4,000 golden eagles, 400 bald eagles and a variety of other raptors,” he said. “Right now, the numbers have dropped, they’ve dropped by about 1,000 in the spring and fall.”
Hansen says there are likely a variety of reasons for the long-term decline, but believes human activities are responsible.
In 30 years of counting in the spring and fall, seven days a week, from sun up until sun down, volunteers have spent a total of 6,031 days in the field – or 56,176 hours – and recorded a grand total of 296,728 migrating raptors from 18 different species, including 230,041 golden eagles.
Caroline Lambert has volunteered for six years and is also active in the greater bird watching community.
“These kinds of studies have to be done over super long periods of time,” said Lambert. “Because this season, so far, we’re really low. We’ve had 122 up until yesterday and we’ve got five or six more today, and that is maybe about 200 less than normal for this time of year.”
Lambert says the low numbers recorded since March 1 are likely due to bad weather along the mountain range. She’s invested in quality binoculars to help her spot the raptors on their migration –they travel fast and are thousands of meters away – but she’s learned to recognize specific markings on them to help identify their age.
“Juvenile golden eagles usually have a lot of white in their wings, and a broad white band at the base of their tail,” she said. “As they get older, they moult in browner feathers and so those white patches begin to get smaller; most of the adults have no white at all so we’re able to kind of make a judgment of their age just by seeing those field marks .”
Rick Robb is in his fifth year volunteering and says it can be hard to see the raptors in flight, but knows the data he’s helping to collect is valuable.
“On days like this, you have to be on your toes to pick them up, and when you see one and if it follows the same trajectory, then you can pick up the next one,” he said.
When this spring’s count started on March 1, it became the count’s 31st consecutive year, making RMERF’s eagle count one of the longest-running citizen science projects in the world.
Learn more about the RMERF and its eagle watch you can visit the organization’s website.