The crested moa, Pachyornis australis, is a species of moa from the family Dinornithidae. It is one of the 11 known species of moa to have existed. Moas are grouped together with emus, ostriches, kiwis, cassowaries, rheas, and tinamous in the clade Palaeognathae. Some of the species of this group are flightless and lacks a keel on their sternum. The name crested moa is due to pits being found in their skulls, suggesting they had crests. These cranial pits are also found occasionally in Dinornis, Anomalopteryx, and other Pachyornis species.
Pachyornis australis weighed around 75 kg (165 lb). The crested moa was smaller than the heavy-footed moa (Pachyornis elephantopus) and their bones are sometimes mistaken for those of P. elephantopus due to their similar structure.
Distribution and habitat
Pachyornis australis was endemic to the South Island of New Zealand, where it occupied the high altitude sub-alpine forests in the North West. It was the ecological equivalent of the heavy-footed moa in the subalpine zone. While their remains have occasionally been found together, the heavy-footed moa generally preferred warmer and drier lowland areas.
Ecology and diet
As with all moa species, the crested moa filled the role of large herbivores in New Zealand, where there are no native terrestrial mammals (excluding bats). The only real threat of predation came from the Haast's eagle (Harpagornis moorei).
Until recently it was thought that Pachyornis australis became extinct at the Pleistocene-Holocene transition roughly 10,000 years ago (10,000 years BP) during a period of significant climatic upheaval. In 2012 however radiocarbon dating of crested moa remains from Bulmer Cavern showed that the specimen died between 1396 and 1442 AD, over 100 years after humans first settled on the Island. During the climatic changes before the settlers arrived, the crested moa followed the changes in elevation of their sub-alpine habitats with little change in their population size. Their extinction (along with all of the other species of moa) relatively soon after the arrival of humans suggests that overhunting and habitat destruction were responsible. It is thought that the last of the crested moa survived in habitats that were less easily accessed by humans.
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