The Northern Mallard occurs naturally throughout the northern hemisphere, and it has been widely introduced to various places in the southern hemisphere, including Australia. Mallards were first released in Australia in the 1860s, and their range has expanded a little in south-eastern parts of the country, but this has occurred quite slowly, and with the aid of repeated releases. Mallards may be the dominant waterfowl in some ornamental lakes, where they interbreed with native species, especially Pacific Black Ducks, but it seldom occurs far from settled areas.
