‘Waterfowl’ is a collective term usually applied to swans, geese and ducks. They all belong to a single family (Anatidae). No other family of birds has suffered so many species extinctions in New Zealand. Seven named species of ducks and two geese have become extinct in the last 800 years, and a tenth extinct species (a shelduck from the Chatham Islands) awaits describing and naming. We also lost the local population of black swan (previously referred to erroneously as the ‘New Zealand swan’), before it was reintroduced in the 1860s.
Part of the reason that most New Zealanders are oblivious to how many species of ducks we have lost is that very few specimens exist for several species. The only extinct species that survived long enough for European naturalists to collect it was the Auckland Island merganser. This is perhaps the only New Zealand bird species where collection of specimens for museums played a dominant role in its extinction. The slightly smaller Chatham Island merganser was described and named as a distinct species in 2014, creating uncertainty about the identity of the few merganser bones from the mainland – are they the same as the Auckland Island or Chatham Island birds, or are they from a third, unnamed, species of New Zealand merganser?
The mainland merganser was not the only extinct waterfowl species for which we have only a few, fragmentary remains. There are three further species for which Te Papa does not have intact skulls in our collections: Scarlett’s duck, New Zealand blue-billed duck and New Zealand musk duck. All three have surviving relatives in Australia (pink-eared duck, blue-billed duck and musk duck respectively), which provide some idea of their likely appearance and ecology. The few bones found indicate that all four species (including the merganser) were rare components of the waterfowl community on lowland lakes. In contrast, bones of several extant duck species (mainly brown teal, grey duck and paradise shelduck) are commonly found at these sites.
The extinct waterfowl species found most abundantly in natural bone deposition sites is Finsch’s duck, which is often found in cave deposits. This terrestrial duck was related to the Australian wood duck, a species which occasionally reaches New Zealand as a vagrant. Finsch’s duck was flightless, or nearly so, with bones of different ages showing a gradual reduction in relative wing size. It was widespread throughout dry eastern regions of both the North and South Islands, and was often found a long way from lakes and rivers.
Perhaps our most enigmatic extinct duck was the Chatham Island duck – a large species found in bone deposits solely on the main Chatham Island. It was an over-sized dabbling duck, similar in size to a paradise shelduck. However, recent genetic comparisons have revealed that it was derived from an ancestor shared with the much smaller brown teal.
The two remaining species of extinct waterfowl were the giants of the family – the North Island goose and South Island goose. Both species were flightless, with the South Island goose estimated to weigh up to 18 kg. This is considerably heavier than a trumpeter swan, the largest living member of the family Anatidae, and similar in size to some of the smaller moa species.
Other blogs in this series:
For more information, check out these bird groups on New Zealand Birds Online:
or visit the Blood Earth Fire | Whāngai Whenua Ahi Kā exhibition at Te Papa
Recently extinct New Zealand waterfowl: North Island goose, South Island goose, Scarlett’s duck, New Zealand blue-billed duck, New Zealand musk duck, Auckland Island merganser, Chatham Island merganser, Finsch’s duck, Chatham Island duck.