page_title: Moa
section_title: Description
hierarchical_section_title: Moa / Description
caption_attribution_description: English: Size comparison between 4 species of moa bird and a human. 1. Dinornis novaezelandiae (3 meters tall). 2. Emeus crassus (1.8 meters tall). 3. Anomalopteryx didiformis (1.3 meters tall). 4. Dinornis robustus (3.6 meters tall).
context_page_description: Moa were nine species of now-extinct flightless birds endemic to New Zealand. The two largest species, Dinornis robustus and Dinornis novaezelandiae, reached about 3.6 m in height with neck outstretched, and weighed about 230 kg while the smallest, the bush moa, was around the size of a turkey. Estimates of the Moa population when Polynesians settled New Zealand circa 1280, vary between 58,000 to c. 2.5 million.
  Moa belong to the order Dinornithiformes, traditionally placed in the ratite group. However, their closest relatives have been found by genetic studies to be the flighted South American tinamous, once considered to be a sister group to ratites. The nine species of moa were the only wingless birds lacking even the vestigial wings that all other ratites have. 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 the Haast's eagle. Moa extinction occurred around 200 years after human settlement primarily due to overhunting by the Māori.
context_section_description: 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, in the manner of a kiwi. The spine was attached to the rear of the head rather than the base, indicating the horizontal alignment. This would have let them graze on low vegetation, while being able to lift their heads and browse trees when necessary. This has resulted in a reconsideration of the height of larger moa.
  
  No records survive of what sounds moa made, though some idea of their calls can be gained from fossil evidence. The trachea of moa were supported by many small rings of bone known as tracheal rings. 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. They are the only ratites known to exhibit this feature, which is also present in several other bird groups, including swans, cranes, and guinea fowl. The feature is associated with deep resonant vocalisations that can travel long distances.
caption: A size comparison between four moa species and a human1. Dinornis novaezealandiae2. Emeus crassus3. Anomalopteryx didiformis4. Dinornis robustus
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