Volunteers keep an eye on Colorado bald eagles
HYGIENE, Colo. — Anne Barela spotted the bald eagle as it glided towards its nest in distant cottonwood.
"And there we have one," she said. A grin crept across Barela’s face as she kept her binoculars trained on the nest.
Every week, Barela visits six bald eagle nests near her home in Longmont to keep tabs on the nests’ condition and the birds that reside there every spring. She is one of more than 100 volunteers with Bird Conservancy of the Rockies who monitor nests across Colorado. Bald eagles, which can live 20 to 30 years in the wild, often return to the same nest year after year.
Widespread use of the insecticide DDT decimated eagle populations after World War II. By the end of the 1970s, there were only three known bald eagle nests in Colorado.
Thanks to environmental protections, like a 1972 law that banned DDT, bald eagle populations have largely recovered. Scientists estimate the state is now home to 300 nesting pairs.
But researchers still aren’t sure how rapid development along the Front Range could affect bald eagle numbers. The bald eagle watch program — which began in Colorado in 1988 — continues to provide critical population data that guides conservation decisions.
It’s surprising “that eagles continue building closer and closer to human development,” said Reesa Conrey, an avian scientist with Colorado Parks and Wildlife.
Conrey is part of a team of researchers who began studying eagles along the Front Range in 2020.
“Eagles are finding these open patches within a larger landscape that contains a lot of human development — parks, areas around reservoirs, rivers, prairie dog colonies — and they're able to be successful in those kinds of environments,” Conrey said.
At the same time, eagles appear to be dying at higher rates. Of the birds CPW has tagged since 2020, 28% have died. Researchers are still crunching the numbers, but early findings suggest “that survival is lower than we might have anticipated,” Conrey said.
Electrocution from power lines and vehicle strikes are the leading causes of death. West Nile Virus and bird flu also pose a threat to bald eagles.
In Fort Collins, volunteer Nancy Morgan monitors a nest that’s practically in her backyard.
When eagles first showed up near her house six years ago, Morgan was frustrated that her neighbors continued to walk dogs and mow their lawns so close to the nest.
But the birds don’t seem to mind, Morgan said. They seem “pretty adaptable.” Every week, she spends a few hours watching the eagles and submits her observations to Bird Conservancy of the Rockies.
Without more money or staff, it would be impossible for CPW to cover as much ground as the 100-plus volunteers who participate in the bald eagle watch program, said volunteer coordinator Jan Snyder.
Morgan, 70, grew up when seeing a bald eagle was still rare. Since becoming a nest monitor, eagle sightings are common.
“It still inspires me to see them,” Morgan said. “It’s cool to be a citizen scientist and to be able to do what little we can to try and make it better.”
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