(Abstract from 'The ducks of Macquarie Island')
Early reference to waterfowl on Macquarie Island and observations made by ANARE expeditioners between 1949 and 1985 are reviewed and discussed. Apart from a unique (perhaps erroneous) record of a mute swan Cygnus olor, information is restricted to the Pacific black duck Anas superciliosa, the grey teal A. gibberifrons and the alien mallard A. platyrhynchos and its hybrids.
Black duck and grey teal were seen by early visitors to the Island, but despite the infrequent potential for escapes of domestic ducks, mallards were not recorded until 1949. Occasional teal and mallards were seen in the years following the establishment of the permanent scientific station (1948) but mallards (and hybrids) have become more numerous in recent years. Though grey teal may disperse to Macquarie Island in times of drought on the Australian mainland, the source of mallards may be New Zealand or the less distant Campbell and Auckland Islands.
The few available records of breeding (eggs, ducklings and nests) for black duck suggest that laying begins in September and extends at least into January. Zooplankton is most abundant in spring and summer, but ducks may obtain high protein foods from the littoral and sublittoral areas and may also take seeds of terrestrial plants.
Available information does not allow separation of habitats used by black duck or mallards. However, most observations are around coastal areas. There is some indication that records have increased along the south-western and eastern sides of the Island, but generally there are few observations of either species on the higher, central plateau.
The intrusion of mallards onto the Island and the resultant hybridisation with black duck poses a threat for the future integrity of the latter native species.
This dataset contains a review of the data available for Pacific black duck (Anas superciliosa), mallard (Anas platyrhynchos) and grey teal (Anas gibberifrons) and hybrids on Macquarie Island, collected from mid-1949 to January 1985. There is a period of relatively continuous and extensive data between February 1963 and January 1985. Discussion and references about habitat, breeding, feeding and hybrids is provided in the dataset (see the reference), as well as distribution maps.
The fields in this dataset are: