Data Zone
Justification of Red List category
This species was formerly found on the Auckland Islands, New Zealand, but it is now Extinct, primarily due to hunting. It was last recorded in 1902, and had been lost by the time a reserve was set up on the islands in 1910.
Population justification
No extant population remains.
Mergus australis was restricted to the Auckland Islands, New Zealand, by the time of its discovery in 1840 (Stattersfield et al. 1998), but subfossil remains of a Mergus species have also been found on South and Stewart Islands. At least 26 specimens were collected in total, the last in 1902 (Kear and Scarlett 1970); there have been no records since, despite intensive searches (Williams and Weller 1974).
It was largely a freshwater species, foraging in inland streams, estuaries and, occasionally, sheltered bays (Kear and Scarlett 1970).
Its decline was presumably caused by a combination of hunting and predation by introduced pigs, rats, cats and dogs (Kear and Scarlett 1970) - the species' incipient flightlessness made it especially vulnerable (Livezey 1989).
Text account compilers
Brooks, T., Mahood, S., Vine, J., Khwaja, N.
Recommended citation
BirdLife International (2024) Species factsheet: New Zealand Merganser Mergus australis. Downloaded from
https://datazone.birdlife.org/species/factsheet/new-zealand-merganser-mergus-australis on 26/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 26/12/2024.