A large, familiar duck that is common across much of its broad range. The male is easy to recognise, with a glossy green head, yellow bill, chestnut breast, and grey body. The female is mottled brown and shows orange and black markings on the bill. It occurs wherever there is water, from urban parks and small streams to a wide variety of wetlands. Often seen in flocks, it readily mixes with other duck species. In North America, females can resemble American Black Duck, Mottled Duck, and Mexican Duck where their ranges meet, though those species are generally darker overall. A look at the wing can help: the white borders around the blue wing patch are usually more pronounced. This species frequently hybridises with them, which can make identification challenging; birds showing lots of white in the tail or curled feathers above the tail often indicate mixed ancestry.