March 21, 2017

25 Years of Mountaintop Eagles

Yesterday, 323 Golden Eagles flew north over Mount Lorette, in Kananaskis Country, southeast of Banff.

If that strikes you as a very specific number, it is. And that's because for exactly twenty five years, dozens of keen volunteer bird watchers have been counting the Golden Eagles that migrate along the backbone of the Canadian Rockies every spring and fall.

On March 20, 1992, Des Allen and Peter Sherrington were doing a general bird survey in the Kananaskis Valley when they first noticed Golden Eagles flying high along the ridgetops. They saw over a hundred that day, but when they looked for other records of large numbers of eagles, they could find nothing even close.

They started watching, and they got others to watch too.  We remember that spring, because we heeded the call to volunteer. It was our very first summer in Lake Louise, and we spent a day in lawn chairs beside Banff's Lake Minnewanka, peering through binoculars to look for the mysterious eagles. And that's when we learned why nobody had noticed what Des and Peter had found that spring: you couldn't see these gigantic birds with your naked eyes! It seems impossible -- they can have 7-foot wingspans -- but they were flying so high that you needed to pick them out with scopes or binoculars.

The golden eagle migration down the spine of the Rockies.
Courtesy of the Rocky Mountain Eagle Research Foundation.
Since 1992, observers have spent over 4500 days in the field, and they've counted more than 180,000 Golden Eagles in total.  The birds are believed to nest in the Yukon and Alaska, and their wintering grounds stretch from Montana to Mexico.

On this, the first full day of spring, let's celebrate nature's splendour, and tip a hat to Peter and Des for their epic discovery.

If this blog post has made you curious about birds, we offer private birdwatching trips in June and early July every year. Come join us!