In order to understand the health of an ecosystem on the ground, wildlife biologists often look to the skies. Top predators like raptors are sensitive to changes in the environment and can serve as an indicator of environmental health. That’s why Colorado Parks and Wildlife’s Raptor Monitoring Volunteer Program is so important.
On Thursday, April 5, I had the privilege of joining CPW volunteers from the Colorado Springs area to learn more about the Raptor Monitoring Volunteer Program and discover some of the rewards and challenges volunteers face.
Our first stop seemed unlikely: a maintenance shed parking lot near the iconic Garden of the Gods park. On the backside of one of the area’s sandstone rock formations, a raptor nest has changed talons a few times over the past few years.

Volunteer Tammy Stahly is responsible for monitoring this nest. She said it used to house golden eagles, but now, a pair of red-tailed hawks have taken up residence and are taking turns sitting on their eggs. Stahly visits the nest every four to five days. As our group grabbed spotting scopes and binoculars, Stahly said the last time she was here, “I got to see the male on the nest, and he was really impatient. He’d get up every few minutes and fly around looking for the female.”
Stahly and the other volunteers for CPW’s southeast region report to CPW wildlife biologist April Estep. Estep runs raptor monitoring for the entire southeast part of the state. “We go as far north as Douglas County and east to the Kansas border,” Estep said.

It takes time to recruit, screen and train volunteers to collect data for CPW, but Estep said the payoff is that volunteers can leverage a biologist’s workload and collect more critical data than one biologist could gather alone. The use of important raptor data helps CPW coordinate habitat planning and management with federal agencies such as the U.S. Forest Service, the Bureau of Land Management, the U.S. Air Force Academy, as well as many cities, counties and open space organizations.
The amount of work required for raptor monitoring is more than many people realize. Many of the nests require long hikes to reach and they must be monitored on a regular basis. Estep said around half of the volunteers she trains each year drop out. Still, it is rewarding work and many stick with it. In CPW’s Southeast Region, more than 60 volunteers gave their time to help CPW with raptor monitoring last year. In Colorado Springs, volunteers have contributed over 4,500 hours since 2013, equaling $108,000 in labor.
At the nest sites, CPW volunteers fill out data sheets indicating species observed, time of day, locations, number of nestlings and if the adults are bringing the nestlings food. Volunteers also take note of disturbances.
“The volunteers record if they’re seeing differences in behavior because of cars or planes,” Estep said. “Sometimes it can be hard to say if they’re being disturbed. Even if we don’t observe any changes with our eyes, we know there are studies that show their heart rates will go up if a plane passes overhead or a car goes by.”
Each kind of raptor has a recommended buffer distance that volunteers adhere to in order to protect the birds. Volunteer Coordinator Jena Sanchez said, “We remind folks to use optics and not to get too close. If they look agitated, you’re too close.”
After a few minutes observing the red-tailed hawks, our group heads out to monitor more nest sites. After observing a prairie falcon nest in Queen’s Canyon on the western edge of Colorado Springs, we head east to the Bluestem Prairie Open Space to check on a bald eagle nest.

Estep said that a few years ago a bald eagle was killed on one of the power lines here near the Fountain Valley School. “We report where that’s happening so they can retrofit with eagle-safe poles,” Estep said.
Once we had focused our spotting scope, we noted the bald eagle here had acquired a small rabbit and was feeding its young. This eagle had created its nest near a busy maintenance building for the school. We followed the recommended buffer distance even though this particular eagle was actually nesting quite close to human activity.
After monitoring the eagle through the spotting scope, our eyes gradually drifted to our more immediate surroundings. With his binoculars, longtime volunteer Bill Bane spotted a herd of pronghorn that had taken up residence in the drained Big Johnson Reservoir. In the sky above them, a red-tailed hawk and a northern harrier had become engaged in territorial aerial combat. They circled and dived at each other, the harrier not backing down.
When they finally separated, we pulled our eyes away from our binoculars, grateful for the spectacle we had just witnessed.
“I guess the harrier made his point,” Bane said.
Tips on viewing raptors and other birds from CPW Wildlife Biologist April Estep
- It’s important for people to realize their impact on the local environment when they are out recreating. For example, it is important to keep a respectful distance from nests and fledglings, such as great horned owlets. The owlets branch (walking and hopping along branches in the nest tree and surrounding trees before they can fly). It is best to leave the birds alone and continue to let their parents take care of them. Do not pick up birds or wildlife on the ground as young birds spend days on the ground learning to fly. If you think you observe a raptor in distress, contact your local CPW office or the Nature and Raptor Center of Pueblo.
- Colorado is lucky to have amazing raptor species to view and enjoy. A good pair of binoculars or spotting scope will allow you to enjoy the species year-round without harassing the birds. When viewing wildlife, if the bird seems agitated, you are probably too close and should back away, giving birds plenty of space to raise their young without disturbance from humans or pets.
- CPW uses the State Wildlife Action Plan (SWAP) as a strategy for conserving wildlife in Colorado. Colorado’s SWAP is a plan for all of Colorado. The task of conserving and managing Colorado’s wildlife is too big for any one group or agency to achieve alone. It takes cooperation and participation from multiple groups to conserve our wildlife.
- People can get involved in this great citizen science project by watching the volunteer website and future training opportunities at www.cpw.state.co.us/volunteer. Most trainings for 2018 are complete but there may be openings in your area, so check back in early 2019.
- For more information on volunteer orientations in the Southeast Region, contact jena.sanchez@state.co.us.
2018 is the Year of the Bird
2018 marks the centennial of the Migratory Bird Treaty Act, the most powerful and important bird-protection law ever passed. In honor of this milestone, nature lovers around the world are joining forces to celebrate 2018 as the “Year of the Bird.” Learning more about birds in your area is a great way to participate in the Year of the Bird. Find out how you can participate and take the Bird Your World Pledge.