Mountain Bluebird Caught in Spring Snowstorm -- Mountain Bluebirds are in need of additional housing. These beautiful songbirds are secondary cavity nesters: they depend on nest holes abandoned by woodpeckers. But as woodpeckers decline and habitat is lost, bluebirds are finding fewer nest cavities and are facing greater competition for these nests from introduced species such as European Starlings and House Sparrows. Hoping to prevent further declines in bluebird populations, birdwatchers and other concerned individuals are constructing man-made nest boxes for the birds. © STEVEN HOLT/STOCKPIX.COM 2001