The crested moa (''Pachyornis australis'') is an extinct species of
moa
Moa are extinct giant flightless birds native to New Zealand.
The term has also come to be used for chicken in many Polynesian cultures and is found in the names of many chicken recipes, such as
Kale moa and Moa Samoa.
Moa or MOA may also refe ...
. It is one of the 9 known species of moa to have existed.
Moa are grouped together with
emu
The emu () (''Dromaius novaehollandiae'') is the second-tallest living bird after its ratite relative the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus '' Dromaius''. The emu ...
s,
ostrich
Ostriches are large flightless birds of the genus ''Struthio'' in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, and kiwis. There ...
es,
kiwi
Kiwi most commonly refers to:
* Kiwi (bird), a flightless bird native to New Zealand
* Kiwi (nickname), a nickname for New Zealanders
* Kiwifruit, an edible berry
* Kiwi dollar or New Zealand dollar, a unit of currency
Kiwi or KIWI may also ref ...
tinamou
Tinamous () form an order of birds called Tinamiformes (), comprising a single family called Tinamidae (), divided into two distinct subfamilies, containing 46 species found in Mexico, Central America, and South America. The word "tinamou" come ...
s in the cladePalaeognathae. Some of the species of this group are flightless and lacks a
keel
The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...
on their
sternum
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sha ...
. The name crested moa is due to pits being found in their skulls, suggesting they had crests of long feathers. These cranial pits are also found occasionally in ''
Dinornis
The giant moa (''Dinornis'') is an extinct genus of birds belonging to the moa family. As with other moa, it was a member of the order Dinornithiformes. It was endemic to New Zealand. Two species of ''Dinornis'' are considered valid, the North ...
Pachyornis
''Pachyornis'' is an extinct genus of ratites from New Zealand which belonged to the moa family. Like all ratites it was a member of the order Struthioniformes. The Struthioniformes are flightless birds with a sternum without a keel. They al ...
'' species.
Description
The crested moa weighed around . The crested moa was smaller than the heavy-footed moa (''
Pachyornis elephantopus
The heavy-footed moa (''Pachyornis elephantopus'') is a species of moa from the lesser moa family. The heavy-footed moa was widespread only in the South Island of New Zealand, and its habitat was the lowlands (shrublands, dunelands, grasslands, ...
'') and their bones are sometimes mistaken for those of ''P. elephantopus'' due to their similar structure.
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 color or size can only be speculated at.
Distribution and habitat
The crested moa was
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, where it occupied the high altitude
sub-alpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
forests in the North West, particularly in the
Nelson
Nelson may refer to:
Arts and entertainment
* ''Nelson'' (1918 film), a historical film directed by Maurice Elvey
* ''Nelson'' (1926 film), a historical film directed by Walter Summers
* ''Nelson'' (opera), an opera by Lennox Berkeley to a lib ...
area. Crested moa remains have been found in the Honeycomb Hills Cave and other caves in the vicinity. 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. However, it is likely the crested moa would have migrated from the high country to these more hospitable areas in winter.
Ecology and diet
As with all
moa
Moa are extinct giant flightless birds native to New Zealand.
The term has also come to be used for chicken in many Polynesian cultures and is found in the names of many chicken recipes, such as
Kale moa and Moa Samoa.
Moa or MOA may also refe ...
bats
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bir ...
). The only real threat of predation came from the
Haast's eagle
Haast's eagle (''Hieraaetus moorei'') is an extinct species of eagle that once lived in the South Island of New Zealand, commonly accepted to be the pouakai of Māori legend.
Extinction
Until recently it was thought that the crested moa became extinct at the
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
-
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...
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
In population genetics and population ecology, population size (usually denoted ''N'') is the number of individual organisms in a population. Population size is directly associated with amount of genetic drift, and is the underlying cause of effect ...
. 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 (unlike every other species of moa), it seems likely that their populations were too isolated and remote to have been accessed by humans. Instead, it is probable that the crested moa were wiped out by introducedmammals.