Mountain Bluebird

Mountain Bluebird with a moth in his beak

Doug Owen

Sialia currucoides

Description

• medium-sized songbirds
• adult males are bright blue, while females have dull gray bodies with blue wings.
• related to robins and thrushes

Habitat

Mountain bluebirds are one of the most conspicuous birds around Craters of the Moon's Loop Road. The only bluebird normally found above 5000 feet in elevation, the mountain bluebird is common throughout the northern portions of Craters of the Moon from March – October.

Behavior

During the summer months, mountain bluebirds feed primarily on insects. They forage by perching on shrubs or tall grasses and often hover before catching prey on the ground or in mid-air. During the spring and early summer, look for them feeding on tent caterpillars on shrubs. Like robins and other thrushes, they will eat berries and small fruits when available.

This flexibility allows them to migrate north earlier than most birds, and their arrival in March is a sure sign the winter is beginning to release its snowy grip on Craters. Large flocks begin arriving in early March and are seen again in early October while on the way south for the winter.

All bluebirds nest in cavities, such as old woodpecker holes and rotted-out areas in trees. All three species of bluebirds in North America have declined, as forests have been cleared and dead trees cut down for firewood, safety, or aesthetic reasons. Natural tree cavities have never been abundant, so bluebirds are competitive and aggressive toward one another.

Why Do Bluebirds Come to Craters?

Research in the 1980s found that mountain bluebirds were most abundant in the lava fields at Craters of the Moon and around the volcanoes in the Cascade Mountains. As it turns out, bluebirds don't have to nest in trees! Any hole or closed-in space that is big enough and has an entrance the right size (about 1 ½ to 2 inches) can be used. The lava fields at Craters of the Moon have an abundance of crevices and pockets that are just the right size for nesting bluebirds. This means that the availability of roosting and nesting sites does not limit the number of bluebirds, as it does in most of North America. What limits the number of bluebirds here is the availability of insects to eat and their willingness to tolerate each other. This adds up to bluebirds being one the most commonly-seen birds at Craters of the Moon. When driving the Loop Road or walking a trail, watch for a flash of blue against the black lava as a mountain bluebird flies by.

 

Did you know?

Like other blue-colored birds, mountain bluebirds have no pigments in their feathers! The microscopic structure of the feathers reflects sunlight in the same way that molecules of air in the sky make the sky look blue. Just like the sky looks gray on a cloudy day, bluebirds appear to "fade" when clouds hide the sun. The state bird of Idaho is well represented here at Craters of the Moon.

 

Birding at Craters? Explore the bird checklist to find out which species to look for!