Mergus australis (Aukland Island Merganser)

[Melanie]

Auckland Island Merganser Mergus australis was restricted to the Auckland Islands, New Zealand, by the time of its discovery in 1840, but subfossil remains of a Mergus species have also been found on South and Stewart Islands. It was largely a freshwater species, foraging in inland streams, estuaries and, occasionally, sheltered bays. Its decline was presumably caused by a combination of hunting and predation by introduced pigs, rats, cats and dogs—the species' incipient flightlessness made it especially vulnerable. At least 26 specimens were collected in total, the last in 1902; there have been no records since, despite intensive searches.

[Melanie]

Picture click here

In Roman times the word Mergus, a diver, was applied by Pliny and Ovid to a kind of water-fowl. The vernacular 'merganser' apparently originated with the German naturalist Gesner (1516-65), whom Cuvier termed the German Pliny. In his Historia Animalium (1555) Gesner used the term Merganser - a combination of the latin words mergus and anser (goose) - for the group of fish eating ducks with great diving ability that Linnaeus later classified as Mergus. Mergansers constitute a subfamily of the Anatidae (ducks) characterised by a long, narrow bill with a hooked tip and with the edges of both mandibles set with numerous horny denticulations. In other ways they quite closely resemble diving ducks in structure.

There are four northern hemisphere species of Mergus and two in the southern hemisphere, the Auckland Island Merganser and one in Brasil. The closest relatives of the Auckland Island merganser are the Chinese merganser and the goosander, both of which occur in eastern Asia. Our merganser may owe its origins to the ancestors of one of these species during a hypothetical period when trans-equatorial migration had been adopted during the Pleistocene. Its evolution, primarily in New Zealand, entailed changes that are repeated in other bird colonists of southern islands, loss of male plumage, loss of pattern in the downy chick, and increasing tameness, if not reduction in the powers of flight. The only brood ever seen apparently consisted of four ducklings, suggesting that the clutch size may have been considerably less than that of the northern hemisphere species; reduced clutch size is another characteristic of insular forms.
Merganser bones from coastal sand dunes, some of them from the middens of the Maori and the moa-hunters who preceded them, have been identified by Scarlett, at first from South Island coastal deposits at Wairau Bar, Lake Grassmere, Kaikoura, and Old Neck, Stewart Island. With the Moas, the merganser disappeared from the main islands during the period of Maori occupation, probably as a result of ecological changes that the arrival of homo sapiens brought about with the introduction of the Polynesian rat and dog, extensive use of fire, and hunting pressures. The merganser remained in the Auckland Islands but the introduction of the pigs (1807) and cats (1820) must have begun to reduce the population even before it was discovered in 1840. Some twenty six skins were collected during the next sixty-two years. The last known birds were a pair shot on 9 January, 1902, by the Earl of Ranfurly, the skeletons of which are now in the British museum.

Credit: Kear, J., and Scarlett, R.J., 1970, Wildfowl, Vol.21.

www.nzbirds.com/AucklandIslandmerganser.html

[another specialist]

www.camacdonald.com/birding/ZINDEX-A.html

[another specialist]

melanie said:

Auckland Island Merganser Mergus australis was restricted to the Auckland Islands, New Zealand, by the time of its discovery in 1840, but subfossil remains of a Mergus species have also been found on South and Stewart Islands. It was largely a freshwater species, foraging in inland streams, estuaries and, occasionally, sheltered bays. Its decline was presumably caused by a combination of hunting and predation by introduced pigs, rats, cats and dogs—the species' incipient flightlessness made it especially vulnerable. At least 26 specimens were collected in total, the last in 1902; there have been no records since, despite intensive searches.

source of info

www.birdlife.net/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=503&m=0

[another specialist]

I see your using the site i found first for the images on all the other waterfowl postings i've done...

I was just doing to do this one next - the last and final one

[sebbe67]

The Auckland Islands Merganser ('''''Mergus australis''''') was a typical merganser which is now extinct. This duck was similar in size to the Red-breasted Merganser. The adult male had a dark reddish-brown head, crest and neck, with bluish black mantle and tail and slate grey wings. The female was slightly smaller with a shorter crest. This bird was first collected when the 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 last sighting was of a pair shot on January 9, 1902. Subsequent fossil discoveries suggest that this Merganser was previously resident on South Island and Stewart Island in New Zealand. category:mergus Category:Extinct birds Category:New Zealand birds

[another specialist]

source for info above

www.answers.com/topic/auckland-islands-merganser

[another specialist]

Gap in nature

[sebbe67]

Potential subsequent reports in 1905 and 1909.

Source: The book Antarctic wildlife

[peej2]

I thought that I had seen an image of a live auckland island merganser on a thread...or was that a different subspecies of merganser that was exticnt? Or I'm I just seeing things?

[sebbe67]

I dont think there is any photos of living birds, its easy to missindetify mergansers becuase three of the species look much the same

[peej2]

Allright, just wondering. I'm always in a continuous search for photographs of extinct animals. I'm just not sure which ones have been photographed. So far I have 25 black and white images of extinct animals. 12 birds, 1 reptile, 7 carnivores, 5 hooved animals.

[cryptodude100]

What is the size of the aukland island merganser compared to the living mergansers?

[Melanie]

Here are some sizes:

Mergus australis 58 cm
Mergus octosetaceus 49 - 56 cm
Mergus squamatus 52 - 58 cm
Mergus serrator 58 cm
Mergus merganser 60 cm
Mergus cucullatus 45 cm
Mergus albellus 45 cm

[cryptodude100]

thanks melanic

[sebbe67]

collections.tepapa.govt.nz/welcome.aspx?ReturnUrl=%2fobjectsearch.aspx (found by adzebill)

[another specialist]

New Zealand Extinct Birds
Brian Gill and Paul Martinson

[sebastian]

PHYLOGENETIC RELATIONSHIPS AND INCIPIENT
FLIGHTLESSNESS OF THE EXTINCT AUCKLAND ISLANDS MERGANSER

BRADLEY C. LIVEZEY’

ABSTRACT. Phylogenetic relationships and evidence for pectoral reduction in the extinct
Auckland Islands Merganser (Mergus austrulis) were investigated using a plumage-based
phylogenetic analysis of the six Recent species of merganser and morphometric comparisons
of study skins and skeletal specimens. The hypothesized phylogeny indicates that M. australis
diverged from the other Mergus immediately after the Hooded Merganser (Lophodytes
cucullutus) and is a member of a basal grade of comparatively small, southern hemisphere
mergansers; the Brazilian Merganser (M. octosetaceus) branched next and is the sister-group
to the larger, more derived, northern hemisphere species ofMergus. M. austrulis was unique
in its natal and adult plumage characters, including the sexually monochromatic plumage
of adults. Morphometric analyses revealed that M. austrulis was the smallest member of its
genus but possessed the longest bills and relatively short wings and tails. Based on regression
estimates of body mass and wing area for M. australis, the species had estimated wingloadings
which exceed those for other Mergini and approach the threshold of flightlessness
hypothesized by Meunier (195 1). Skeletal comparisons confirmed that M. austrulis had
exceptionally long bills, and this also revealed that the species possessed relatively short
wing elements and scapulae, as well as sterna characterized by shallow carinae and small
caudal widths. These morphologicalc haracteristics, hypothesized phylogenetic relationships,
and ecological information for M. austrulis are compared to the typical correlates of insularity
in waterfowl listed by Weller (1980) and the evolutionary implications of these characteristics
are considered. Received 26 May 1988, accepted I Nov. 1988.

Full pdf article: elibrary.unm.edu/sora/Wilson/v101n03/p0410-p0435.pdf

[noxomanus]

What I always find the most unusual about Mergus australis is its distribution. There are two or three Mergus species in the Northern Hemisphere and one in Brazil......what was this species doing at the Auckland Islands?

I suspect Mergus was much more widely distributed in the not-all-too-distant past, say, the Pliocene or even still in the Pleistocene. My vote goes to the Pliocene. All kinds of piscivorous birds seem to have been much more numerous and diverse then, so perhaps the same was true of mergansers.

[another specialist]

Flightless Birds By Clive Roots

books.google.co.uk/books?id=Sb1IJYzXZhUC&pg=RA1-PT39&dq=King+Island+Emu&sig=RV6rcupVacTpxrFr6YnsrohkfO8#PRA1-PT45,M1