These songbirds range from Alaska to western Texas at elevations above 6,000 feet. More richly blue than their eastern or western cousins, males are azure from head to tail, while females are light gray with blue-tinted wings. They nest in ground holes and tree cavities, preferring forests with snags (standing dead trees). To hunt, they perch on low branches, then drop down to pounce on beetles and caterpillars. Once displaced from their nests by more aggressive English sparrows, bluebirds have rebounded in recent decades due to nest-box programs across North America.