| Crested moa Temporal range: LateHolocene | |
|---|---|
 | |
| Pachyornis australis bones inNgārua Caves | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Infraclass: | Palaeognathae |
| Order: | †Dinornithiformes |
| Family: | †Emeidae |
| Genus: | †Pachyornis |
| Species: | †P. australis |
| Binomial name | |
| †Pachyornis australis | |
| Synonyms | |
List
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Thecrested moa (Pachyornis australis) is anextinct species ofmoa. It is one of the 9 known species of moa to have existed.[3]
Moa are grouped together withemus,ostriches,kiwi,cassowaries,rheas, andtinamous in thecladePalaeognathae. Some of the species of this group are flightless and lacks akeel on theirsternum.[4] The name crested moa is due to pits being found in their skulls, suggesting they had crests of long feathers.[3][5] These cranial pits are also found occasionally inDinornis,Anomalopteryx, and otherPachyornis species.[6]
The crested moa weighed around 75 kg (165 lb).[citation needed] The crested moa was smaller than the heavy-footed moa (Pachyornis elephantopus) and their bones are sometimes mistaken for those ofP. elephantopus due to their similar structure.[7][8]
Almost nothing is known about the feather pits on the crested moa's skull. It is likely the feathers were used in courtship rituals or to challenge rivals, but no feathers have been found, so their colour or size can only be speculated at.[3]
The crested moa wasendemic to theSouth Island ofNew Zealand, where it occupied the high altitudesub-alpine forests in the North West, particularly in theNelson area.[3][8][9] Crested moa remains have been found in theHoneycomb Hills Cave and other caves in the vicinity.[3] It was the ecological equivalent of the heavy-footed moa in thesubalpine zone. While their remains have occasionally been found together, the heavy-footed moa generally preferred warmer and drier lowland areas.[7][8][9] However, it is likely the crested moa would have migrated from the high country to these more hospitable areas in winter.[3]
As with allmoa species, the crested moa filled the role oflarge herbivores in New Zealand, where there are no nativeterrestrial mammals (excludingbats).[8][10] The robust beak with a pointed tip, sturdy jaws, together with large numbers of gizzard stones suggests the diet of Pachyornis was high in fibrous plant material such as branches of trees and shrubs.[5] The only real threat of predation came from theHaast's eagle (Hieraaetus moorei).[10]
Until recently it was thought that the crested moa became extinct at thePleistocene-Holocene transition roughly 10,000 years ago (10,000 yearsBP) during a period of significant climatic upheaval.[8][11] In 2012 howeverradiocarbon dating of crested moa remains fromBulmer Cavern showed that the specimen died between 1396 and 1442 AD, over 100 years after humans first settled on the Island.[7][8] 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 theirpopulation size. Despite their relatively low numbers and limited habitat range, their extinction came later than all of the other moa species. Given that there is no evidence that crested moa were ever hunted by humans[5] (unlike every other species of moa), it seems likely that their populations were too isolated and remote to have been accessed by humans.[3][7][8] Instead, it is probable that the crested moa were wiped out byintroducedmammals.[3]