You know what your garden needs? A touch of blue — from a bluebird, that is. In some metro-area neighborhoods you can attract bluebirds to your yard by putting up an artificial nest box.
Nest boxes mimic the tree cavities where bluebirds naturally build their nests. They help replace lost habitat that led to steep declines in bluebird populations across North America. Bluebirds like sites at the edge of a woodland or shrubland adjacent to a meadow or grassy area where they hunt grasshoppers and other insects in the grass (sorry, manicured bluegrass lawns don’t support the insects that attract bluebirds).
Suburban areas with greenbelts and open space that have scattered clumps of trees and shrubs are best. In urban areas, house sparrows and starlings often invade boxes and might kill bluebird nestlings.
Place your nest box on a post or tree 5- or more feet above the ground, with a clear flight path and line of sight. Face the hole toward the open area. Homeowners with acreage can set up a line of boxes, called a bluebird trail, with the nests spaced 200 or more yards apart so birds don’t compete for the same prey.
The box’s entrance hole should be 1 1/2-inches across — which is narrow enough to keep predators out and prevent larger usurpers, such as starlings, from moving in.
Make sure there is a hinged side or removable lid so you can monitor the box and clean it out in the fall.
Western and mountain bluebirds will use nest boxes, but don’t be surprised if you attract tree swallows, violet-green swallows, ash-throated flycatchers or house wrens. You can “pair” boxes — one for bluebirds and another next door for a different species.
Peeking in the nest box to find a clutch of sky-blue eggs, hatchlings begging with beaks open wide or birds just about ready to fly is a real treat.
Mary Taylor Young is author of 11 books on Western nature and wildlife, including The Guide to Colorado Birds.
Bluebird box
It isn’t too late to put up a bluebird nesting box. You can purchase them at your local bird supply store or through the Audubon Society of Greater Denver as part of the Colorado Bluebird Project at $25 per box.
Proceeds go to buy materials to make more boxes. Call 303-973-9530 or info@denveraudubon.org.
You can also find plans to build your own at the North American Bluebird Society website, .
Photo by Mary Taylor Young
