The Mallard or Wild Duck is a dabbling duck which breeds throughout the temperate and subtropical Americas, Europe, Asia, and North Africa, and has been introduced to New Zealand and Australia. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae.
Mallards usually form pairs (in October and November) only until the
female lays eggs at the start of nesting season which is around the
beginning of spring, at which time she is left by the male who joins up
with other males to await the moulting period which begins in June.
(Text from :http://en.wikipedia.org/wiki/Mallard )