The name is taken from the male bird’s distinctive red shoulder patches, or “epaulets”, which are visible when the bird is flying or displaying. At rest, the male shows a paler yellow wingbar against a black background. The female is an inconspicuous shade of brown and considerably smaller than than the male. The adult birds are from 7 to 9.5 inches long, and have distinctive sharp bills.
Red-winged blackbirds are one of the most abundant birds in North America. The males are very territorial during breeding season, defending their territory with song and chasing, as seen here.