The Greater Arkansas River Nature Association, along with the Colorado Parks and Wildlife wildlife volunteer program, will once again monitor nest boxes for mountain bluebirds, tree swallows and violet-green swallows around the county beginning this spring.
GARNA has been involved with the project for at least the last 10 years.
“Past findings show that bluebird and swallow populations here are relatively healthy, but just like the rest of the world, bird populations are declining in general,” Dominique Naccarato, GARNA executive director, said.
Nest boxes are built by volunteers and placed all over the county in habitat that is suitable to the bluebird and swallow species.
“These birds are secondary cavity dwellers that experience habitat loss because they depend on dead trees, which are removed more and more due to development and urban environments,” Naccarato said. “The birds are ‘secondary’ cavity nesters because they use cavities in dead trees that have been created by ‘primary’ cavity nesters like flickers and woodpeckers. The ‘primary’ users then move on once they’ve had their fill of insects from the space – their eating of which results in excavation of the cavity.”
Volunteers carefully monitor nest boxes during breeding season and count birds that use the boxes. They’ll also count eggs, hatchlings and fledglings. These numbers are reported to Cornell Nestwatch Program at nestwatch.org/.
“One thing we don’t find is a lot of western bluebirds,” Naccarato said. “In some places, western bluebirds threaten mountain bluebird populations due to changes in the landscape.
“Other threats include natural predators as well as domestic cats and other invasive species, such as house sparrows and European starlings.
“House sparrows flourish when there are buildings nearby, so this is another way that development can be a threat to the native bird populations.
“House sparrows are vicious to the native birds, poking holes in eggs and even killing hatchlings, then building their nests right on top of eggs, hatchlings and all.
“These are the kinds of events that the nest box volunteers monitor.”
Naccarato said they currently have all of the nest box sites covered, but if people want to participate they can contact GARNA at 719-539-5106 or email@example.com.
GARNA will host a virtual trainer refresher course on April 4 for volunteers and others who are interested.