43 cm. 1,150 g. Variable plumage. Bill black. Wings dark gray; outer flight feathers with white base. Legs black. Clear plumage: Head and nape pale gray. Upperparts brown, white edgings and streaks. Underparts pale gray, flanks with paler areas. Dark plumage: Plumage dark brown uniform. A golden band on nape. Intermediate plumage (May-June): Plumage similar to dark, but slightly more clear and streaked. Males and females differ in size, females are larger. Juveniles have dark gray plumage; paler scalloped on face and some wing feathers, more paler on belly. Reach reproductive maturity at 6 years of age.