Very familiar and common duck from city parks to the wildest places, wherever there is water, and also found on farmland. Often tame and approachable. Ancestral stock of many domestic ducks. Pinpointing truly wild birds often tough. Commonly hybridizes, particularly with ABDU. Excellent species to compare with others. Learn the variations! ID: Fairly large, well-proportioned, and muscular. Blue speculum (can appear purple) bordered by black and white. Males have striking green head with white collar. Funky upturned black central uppertail coverts. Bill is bright yellow with black nail. Eclipse male similar to female but generally darker and retains yellower bill. 1st-w male identical to adult male. Female dullish gray-brown, paler on head and neck with dark crown and eyestripe. White outer tail feathers. Variably yellow orange bill with dark center. Young females similar to adult but often have duller bill.