Summer residents of Alaska, northern Canada and the alpine tundra of North America's western mountains, white-crowned sparrows winter across most of the Lower 48 (the Northern Plains, New England and South Florida excluded). There they are usually found in sizable flocks, feasting on a variety of seeds in abandoned farm fields or in shrub lines along pastures; they might also visit feeders, especially in rural towns or semi-rural suburbs.
In Colorado, white-crowned sparrows are among the more common alpine summer residents and are best found near the stunted spruce and bristlecone pines at timberline. While they migrate through the Front Range urban corridor in spring and fall, they are especially abundant in May as they return from the Southern Plains. Here in central Missouri, white crowns are locally common winter residents on the farmlands that surround Columbia and, in my experience, are most often observed at suburban feeders in March or early April.
On their northern or alpine breeding grounds, these slender but hardy sparrows place their nest in low shrubs or directly on the ground; 3-5 young are raised and the family feasts on both insects and seeds throughout the summer months. The male parent is highly territorial during this period and his distinctive song is delivered day and night. By early autumn, the family members disperse; juvenile white-crowns retain their buff-colored head stripes until the following spring and are thus easily identified in winter flocks.
