Page 26 - Canadian Geographic

DISCOVERY
DISCOVERY

PLACE

Golden highway

How Alberta birders-turned-citizen scientists discovered
How Alberta birders-turned-citizen scientists discovered
a golden eagle migration route through the Rockies Alaska-Yukon
golden eagle migration
By Sarah Hewitt

Alaska
Breeding
Yukon range
R
Northwest
O
Territories
C
K
Y

British Alberta

Columbia Hay Meadow

observation site
M
O
Montana
U
N
T
Winter
A
range
I N S
Golden eagle range
Golden eagle migration route
A researcher at Raptor View Research
Institute in Montana releases a wing-
tagged golden eagle. The tags help
spotters easily identify migrating birds.
O volunteer effort to track the eagles’ migra- eagles in earnest, leaving his oil-industry
ON A BRIGHT DAY in early spring, a
In the fall of 1992, he began counting
group of citizen scientists stands in a forest
tion. One March morning in 1992 in
clearing off the Hay Meadow trail in the
Kananaskis Country, Sherrington was
job to start the non-profi t Rocky Mountain
front range of the Rocky Mountains, about
Eagle Research Foundation. To date, thou-
watching a pine grosbeak when he saw a
75 kilometres west of Calgary, binoculars
trained skyward. They’re scanning for golden eagle. Minutes later, two more sands of volunteers have logged more than
eagles fl ew past. By day’s end, he’d counted
30,000 hours in the fi eld, and recorded
golden eagles, one of the largest raptors in 103 eagles, and over the next four days, the sightings of more than 24,000 golden
North America. Before long, a speck count would rise to 400. eagles. They’ve been able to identify not
appears above an unnamed peak. It catches Golden eagles are territorial and have only the migration route along the Rocky
a thermal, circles high and soars overhead home ranges that can cover as much as 200 Mountain front, but also, working with
as the people below strain to glimpse the square kilometres. They’re found through- researchers in Alaska and Montana, a sec-
band of white across the tail base that dif- out the Northern Hemisphere, and the ondary migration corridor farther west
ferentiates a juvenile from an adult. majority of populations studied in Finland through the Rocky Mountain trench.
In the spring and fall, hundreds of and Russia appear to be either year-round “This whole thing is just the result of
golden eagles stream along the Rockies’ residents in their habitat or partial me saying ‘This is interesting, I wonder
eastern ridges on an aerial highway that migrants, meaning only the juvenile birds what’s happening here,’ and then pursuing ROB DOMENECH/RAPTOR VIEW RESEARCH INSTITUTE; MAP: CHRIS BRACKLEY/CAN GEO
stretches from Alaska to Mexico. In the travel far afi eld. The same was thought it,” Sherrington says of his citizen science
Cree lunar calendar, February is known as about the Alaska-Yukon population. No experience. “It’s a case of looking up and
Eagle Moon, yet scientists didn’t know this one suspected they were watching the larg- wondering what’s out there.”
Alaska-Yukon population of the birds est golden eagle migration on the planet.
migrated at all until relatively recently. “When you see something that doesn’t Read an extended version of this story,
“It all happened quite accidentally,” says fi t with the known data, you assume it’s including more on how Peter Sherrington’s
Peter Sherrington, an avid birder who for anomalous, but maybe it’s our know- data is helping conserve golden eagles, at
more than two decades has spearheaded a ledge that’s wrong,” Sherrington says. cangeo.ca/ma18/eagles.

26 CANADIAN GEOGRAPHIC MARCH/APRIL 2018