A warm March day with south winds brings flocks of male red-winged blackbirds into southern Minnesota. In the early spring of 2012 this event took place on March 6, but last year, with the late spring, they first returned on March 28. Both years there was still snow on the ground, and many of us expected more snow and raw winds in the following weeks. However, the first red-wings were back singing their trilled "o-ka-leeee" songs in wetlands, and that was music to our winter-weary ears. The glossy black males have bright red shoulder patches with a light yellow border. For these males it's serious business to return before the females and stake out claims in marshes and along reedy edges of lakes by singing and flashing red from the tops of surrounding vegetation, often cattails.

The females arrive several weeks later. They're sparrow-like birds with white eyebrows but otherwise brown above and streaked with brown below. The drab colors will camouflage the female as she sits quietly on her nest.

One of the most widespread and numerous birds in Minnesota, red-wings winter in southern states, sometimes gathering in large flocks along with grackles and cowbirds. But with the first hint of spring, mature males head north. It takes young males two years to become black and to develop the striking red shoulder patches. Without the bright colors, the first-year males are unable to win territories or brides and so they gather in flocks and wait for next year. Red-wings feed during the day and rest at night. Their food consists of seeds, berries, insects and spiders. They walk on the ground when searching for food.

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.