This is an accepted version of this page See text Moa[note 1] (order Dinornithiformes) are an extinct group of flightless birds formerly endemic to New Zealand.

[4] However, genetic studies have found that their closest relatives are the flighted South American tinamous, once considered a sister group to ratites.

They were the largest terrestrial animals and dominant herbivores in New Zealand's forest, shrubland, and subalpine ecosystems until the arrival of the Māori, and were hunted only by Haast's eagle.

[10] Moa skeletons were traditionally reconstructed in an upright position to create impressive height, but analysis of their vertebral articulations indicates that they probably carried their heads forward,[11] in the manner of a kiwi.

Excavation of these rings from articulated skeletons has shown that at least two moa genera (Euryapteryx and Emeus) exhibited tracheal elongation, that is, their trachea were up to 1 m (3 ft) long and formed a large loop within the body cavity.

The feature is associated with deep resonant vocalisations that can travel long distances.The moa's closest relatives are small terrestrial South American birds called the tinamous, which can fly.

Currently, 11 species are formally recognised, although recent studies using ancient DNA recovered from bones in museum collections suggest that distinct lineages exist within some of these.

[23] These may eventually be classified as species or subspecies; Megalapteryx benhami (Archey) is synonymised with M. didinus (Owen) because the bones of both share all essential characters.

Size differences can be explained by a north–south cline combined with temporal variation such that specimens were larger during the Otiran glacial period (the last ice age in New Zealand).

[19] The presence of Miocene moa in the Saint Bathans fauna seems to suggest that these birds increased in size soon after the Oligocene drowning event, if they were affected by it at all.

[26] Bunce et al. also concluded that the highly complex structure of the moa lineage was caused by the formation of the Southern Alps about 6 Mya, and the habitat fragmentation on both islands resulting from Pleistocene glacial cycles, volcanism, and landscape changes.

The other moa species present in the North Island (Euryapteryx gravis, E. curtus, and Pachyornis geranoides) tended to inhabit drier forest and shrubland habitats.

The beak of Pachyornis elephantopus was analogous to a pair of secateurs, and could clip the fibrous leaves of New Zealand flax (Phormium tenax) and twigs up to at least 8 mm in diameter.

[45] The pairs of species of moa described as Euryapteryx curtus / E. exilis, Emeus huttonii / E. crassus, and Pachyornis septentrionalis / P. mappini have long been suggested to constitute males and females, respectively.

Excavations of rock shelters in the eastern North Island during the 1940s found moa nests, which were described as "small depressions obviously scratched out in the soft dry pumice".

Moreover, sex-specific DNA recovered from the outer surfaces of eggshells belonging to species of Dinornis and Euryapteryx suggest that these very thin eggs were likely to have been incubated by the lighter males.

[51] Studies of accumulated dried vegetation in the pre-human mid-late Holocene period suggests a low Sophora microphylla or Kōwai forest ecosystem in Central Otago that was used and perhaps maintained by moa, for both nesting material and food.

[53][54] Polynesians arrived sometime before 1300, and all moa genera were soon driven to extinction by hunting and, to a lesser extent, by habitat reduction due to forest clearance.

An expedition in the 1850s under Lieutenant A. Impey reported two emu-like birds on a hillside in the South Island; an 1861 story from the Nelson Examiner told of three-toed footprints measuring 36 cm (14 in) between Tākaka and Riwaka that were found by a surveying party; and finally in 1878, the Otago Witness published an additional account from a farmer and his shepherd.

[59] Some Māori hunters claimed to be in pursuit of the moa as late as the 1770s; however, these accounts possibly did not refer to the hunting of actual birds as much as a now-lost ritual among South Islanders.

[60] Whalers and sealers recalled seeing monstrous birds along the coast of the South Island, and in the 1820s, a man named George Pauley made an unverified claim of seeing a moa in the Otago region of New Zealand.

[64] Joel Polack, a trader who lived on the East Coast of the North Island from 1834 to 1837, recorded in 1838 that he had been shown "several large fossil ossifications" found near Mt Hikurangi.

He was certain that these were the bones of a species of emu or ostrich, noting that "the Natives add that in times long past they received the traditions that very large birds had existed, but the scarcity of animal food, as well as the easy method of entrapping them, has caused their extermination".

[67][68] Dieffenbach[69] also refers to a fossil from the area near Mt Hikurangi, and surmises that it belongs to "a bird, now extinct, called Moa (or Movie) by the natives".

[70][71] In 1839, John W. Harris, a Poverty Bay flax trader who was a natural-history enthusiast, was given a piece of unusual bone by a Māori who had found it in a river bank.

His deduction was ridiculed in some quarters, but was proved correct with the subsequent discoveries of considerable quantities of moa bones throughout the country, sufficient to reconstruct skeletons of the birds.

They occur in a range of late Quaternary and Holocene sedimentary deposits, but are most common in three main types of site: caves, dunes, and swamps.

However, the currently accepted explanation is that the bones accumulated slowly over thousands of years, from birds that entered the swamps to feed and became trapped in the soft sediment.

Its iconic status, coupled with the facts that it only became extinct a few hundred years ago and that substantial quantities of moa remains exist, mean that it is often listed alongside such creatures as the dodo as leading candidates for de-extinction.

[88] Heinrich Harder portrayed moa being hunted by Māori in the classic German collecting cards about extinct and prehistoric animals, "Tiere der Urwelt", in the early 1900s.