The development of young Great Horned Owls is prolonged over many months. Typically the female lays two eggs, sometimes more when food is abundant. She uses an old hawk’s nest, crow’s nest, hollow tree, or rock crevice, with the addition of a few feathers as the only improvement. Nesting begins as early as January or February. With such an early start, snowfall may cover the incubating parent and the nest at times. Occasionally the eggs freeze and a new clutch must be laid. After nearly one month, helpless chicks hatch, clad in white, eyes closed. Although the nestlings are unable to fly for ten to twelve weeks, they begin venturing out onto nearby branches after about six weeks. Because fledglings remain dependent on their parents for food until fall, their harsh begging calls may be heard throughout the summer.