The Mallard is New Zealand’s most numerous and most widely distributed waterfowl, occurring right throughout the country. The species is also present in some of the sub-Antarctic islands and Chatham and Kermadec Islands.
From a habitat perspective, Mallard ducks are able to thrive in a wide variety of environments, which would go a long way to explaining why they are such a widespread and rapidly expanding species. Their habitats include urban streams and parks, most flowing rivers and streams, drains in pastoral farming areas, lowland lakes and estuaries and hydro-dams as well as high country tarns. Very adaptable is the old Mallard.
Interestingly, over time, with their rapid expansion (combined with hybridisation) the Mallard has come to 'displace' the native Grey duck, causing the Grey duck population to slowly decrease.…