Birds soon to be looking for cavity nesting sites

The past week of snow and frigid weather has been but a minor setback. Bird migrations will be getting into full swing through the Inland Northwest this month as sure as the sun will rise tomorrow.

Birdwatchers already have been reveling about new arrivals at their feeders and favorite birding hot spots.

Tundra swans soon will be flocking through the region as the snow piles transform into wetlands perfect for pit stops on their way to northern breeding grounds. Look for swans in flooded fields around the Cataldo area, in the Reardan ponds, in the Colville Valley and Turnbull National Wildlife Refuge.

While many spring migrants are just passing through, others are zeroed in on this region as their breeding destination. Bluebirds, by their bright color, are among the most noticeable.

Two species of bluebirds live in this region, the western bluebird and the mountain bluebird, which is Idaho’s state bird. The mountain bluebird is larger than the western and both are slightly smaller than robins.

The male mountain bluebird has a very bright back and is pale blue below. The female is mostly gray with a trace of blue on the wings and tail. The western bluebird is less brightly colored and males and females both have rust on the breast.

Thoreau referred to the mountain bluebird as the “bird with the sky on its back” because of the brilliant color it exhibits when the sunlight is refracted as it strikes the feathers.

Bluebirds are ground feeders with special fondness for grasshoppers.

Bluebirds and other cavity nesters such as chickadees and nuthatches are already scoping out sites for this year’s nesting.

These birds have bills that are not suited for creating nest cavities, so they make their nests in existing cavities excavated by woodpeckers or other animals.

Many trees with suitable nesting holes have been cut for firewood, cleared to make way for development or have been occupied by non-native starlings or house sparrows. That leaves cavity-nesting birds with fewer options, and some bluebirds miss out on nesting for lack of a suitable home.

Man-made nest boxes help to fill the shortage of natural nest sites, especially if they are built to the size specifications preferred by different bird species.

Idaho Fish and Game and the Washington Department of Fish and Wildlife have information sheets on bird box dimensions.

Bluebird nest boxes have the greatest likelihood of being used the first year if placed no later than early April.

Savvy birdwatchers clean out their nesting boxes in the fall to make them available as shelter for wintering birds as well as making them ready for the next nesting season.

If you haven’t cleaned out your bird boxes yet, it’s time to get in gear and put out the welcome mat.