Mallard duck bird is the most familiar duck in American region, with very differently plumaged sexes. The mallard duck (male) is distinctive, a fairly robust long-necked bird with a dirty yellow bill, a glossy bottle-green head, white neck ring, purple-brown breast and ash-grey belly sides and upperparts. The wing has a bold speculum of blue or purple, depending on the light, bordered with black and white lines - a feature shared by both sexes. The Mallard duck bird(female) is brown, streaked and spotted overall with black, with a darker crown and eye-stripe. The bill is dull orangey or olive-coloured, with a dark culmen and tip.
The ancestor of the domestic or 'farmyard' duck, the Mallard duck bird is widespread, common, extremely tolerant of humans and very adaptable. It is found in an amazingly wide range of wetland habitats, such as shallow coasts, rivers, lakes, marshes, ditches, man-made water bodies such as reservoirs, parks, ponds, and will use arable fields for grazing. Mallard duck bird always favours shallow water, and can often be seen up-ending as it feeds on underwater vegetation.
The calls of the mallard duck bird (male) and (female) differ somewhat. The male mallard duck bird gives a soft nasal "rrheerrb" or "queep", and often when in a group accompanies this with a low quacking "rhu-rhu-rhu-rhu...". The female gives the classic "quack-quack" call. This call is typically in series of 2-10 notes, with the stress on the first two quacks and then tailing off, such as "Qwah Qwah Qwa qwa wha wha wha wha...". It is frequently uttered, often when flushed or when other Mallard duck birds are in the air nearby. The female also gives variations of these calls, with persistent quacks when advertising, or low chuntering quacks when with young; the latter give a high-pitched "peepee" contact call.