In California, breeds locally on northernmost refuges and in Central Valley. Eats submerged vegetation in sloughs, lakes, and marshes. Feeds in shallower waters than most other divers, often feeding by tipping up in very shallow water. Nest is a down-lined hollow in reeds or grass in marshes where vegetation is dense and deep water close by. Legs are set far back and wide apart which facilitates diving but makes walking awkward.
Heavy bodies require a running start on water for take-off.
Some redheads, particularly those that nest in the Salt Lake area of Utah, migrate east, and some west. A large portion of these birds migrate into the San Francisco Bay, while others go east to the Chesapeake Bay. This duck is easily confused with the canvasback which has the same markings but a much paler back and sides and a longer, slimmer black bill. In California they are becoming increasingly scarce, another victim of shrinking nesting habitat. 3 Hanson, Scott. 1992.