New Zealand merganser

This duck was similar in size to the red-breasted merganser (Mergus serrator). The adult male had a dark reddish-brown head, crest and neck, with bluish black mantle and tail and slate grey wings.[3] The female was slightly smaller with a shorter crest.

Illustration from 1909

Drawing of the head

This bird's Māori name was miuweka.[2] It was first collected when a French expedition led by the explorer Jules Dumont d'Urville on the ships L'Astrolabe and La Zelee visited the Auckland Islands in 1840. Its decline was caused by a combination of hunting and predation by introduced mammals. The bird was not flightless, but rather hard to flush; it preferred to hide between rocks when pursued. The last sighting was of a pair shot on January 9, 1902. It was not found in a 1909 search, and a thorough 1972/1973 exploration of possible habitat concluded that it was long extinct.[4]

Subsequent fossil discoveries suggest that this merganser was previously resident in the South Island, and on Stewart Island/Rakiura in New Zealand. Fossils of a subspecies or closely related species have also been found on the Chatham Islands. There exists a short remark mentioning "a merganser" found on Campbell Island,[5] but this may just as well refer to the semi-marine Campbell teal which is otherwise missing in McCormick's notes: he only mentions the Pacific black duck ("a New Zealand species of duck").[6]