A common bird of the southern and eastern United States, the northern cardinal is expanding its range northward. They're permanent residents in much of southern Minnesota, and a few make their homes in the north. They prefer woodland edges, open woods, parks and back yards with plenty of trees and shrubs for cover. Cardinals often visit feeding stations; sunflower seeds are a favorite, but they also relish cracked corn scattered on the ground.

Cardinals are known to mate for life. During late spring and all summer, we see them in pairs as they defend breeding territories of about 3 acres. But each pair is also part of a larger community. When their territories break down in winter, a dozen or more birds may flock together, all coming to a feeding station at once.

Each year a few northern cardinals are heard singing the rich, whistled "what-cheer, cheer, cheer" songs in January. By early to mid-February, these 9-inch-long songsters are singing loud and long. There are many variations of the song, such as "what-cheer, cheer, cheer, birdie-birdie-birdie" and "cheer, cheer, wit, wit, wit, wit, wit." Both sexes sing these territorial songs, sometimes together.

So, the very early start of the nesting season is marked by renewed singing. As a courtship gesture, the male often feeds the female. In late winter we'll notice this mate-feeding at feeding stations. This is also the time when a cardinal may start to respond to its reflection in a window, attempting to drive away what it considers an intruder. Both sexes do this. Mobiles or sunlight-reflecting ribbon tape hung from the eaves can help break up these futile gestures.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.