One of the largest ducks with a loud quack, sometimes shows features and varied patterns of semi-domestic ducks, but always has a blue wing patch. Drakes retain curly central tail feathers.

There are Mallards on most town and village ponds, although many are of various colour forms that are not found in the wild. The drakes have extraordinary glossy green heads that are shot with blue, lovely purple-blue patches on each wing, and the typical curly black tail feathers that often remain even in domestic forms. Wild Mallards are often unapproachable and nervous, with good reason as so many are shot.