The wings are a metallic brown and green with white rear borders. The smaller female has a brownish head, grey bill and a somewhat pointed tail. Distribution - This duck occurs throughout all of North America, breeding north of their local range and wintering south, sometimes as far as Central America and the West Indies. They prefer marshes, prairie ponds and tundra and may sometimes winter in salt marshes. This widespread and common duck flocks in large groups of up to a thousand.
Males are often aggressive, forcing their attention on females of other species.
It is a grazer.