Almost everywhere in the northern hemisphere.
Marshes, lakes and ponds, fresh water.
The male has a dark, glossy green neck and head with a white neck band dividing the neck from the brown breast. The body is gray. The female is pale brown and completely covered with darker brown flecks. The Mallard's legs are short. The 3 front toes are webbed. The bill is flat and wide.
This duck is a surface-feeder, generally feeding in shallow water. Sometimes it upends the body with the head underwater in order to reach slightly deeper food. Thus it is known as a dabbling duck. It does not dive except in unusual circumstances, but obtains all of its food at or near the surface of the water or on damp ground or vegetation. When alarmed, it springs directly into the air instead of pattering along the surface of the water before taking off, as is common with some other water fowl.
The Mallard normally nests in dense reeds or grass close to fresh water. The nest is usually a hollow lined with dead grass or reeds and filled with down. However, it may nest in a variety of other situations on or off the ground. Mallard drakes in captivity will sometimes hybridize with other females.