[11] The breeding male is patterned grey, with a black rear end, light chestnut wings, and a brilliant white speculum, obvious in flight or at rest.

[12] In non-breeding (eclipse) plumage, the drake looks more like the female, but retains the male wing pattern, and is usually greyer above and has less orange on the bill.

[10][12] In Great Britain, the gadwall is a scarce-breeding bird and winter visitor, though its population has increased in recent years.

In Ireland a small breeding population has recently become established, centred on County Wexford in the south and Lough Neagh in the north.

[14] The gadwall is a bird of open wetlands, such as prairie or steppe lakes, wet grassland or marshes with dense fringing vegetation, and usually feeds by dabbling for plant food with head submerged.

Pair formation begins during fall migration or on breeding grounds, but has also been reported to occur in August when males are still in eclipse plumage.

The male utters a mep call during a display known as the burp, where he raises his head pointing his bill towards a female.

Gadwalls are one of the most hunted duck species (3rd to the mallard and green-winged teal), with 1.7 million shot each year.