South Island giant moa

Moa were ratites: large, flightless birds with a sternum, but lacking a keel.{{efn|

Recent genetic research has incorporated the grouse-like Southern American tinamous clearly into the middle of the ratites; so now there are mid-weight ratites which can fly, even though even the tinamous prefer to remain on the ground.}} They also had a distinctive jaw and palate. The origin of these birds is becoming clearer, and it is now believed that early, flighted ancestors of these birds dispersed into the Southern Hemisphere, where most flightless ratites have been found.

{{cite encyclopedia |last=Davies |first=S.J.J.F. |year=2003 |title=Moas |editor=Hutchins, Michael |encyclopedia=Grzimek's Animal Life Encyclopedia |edition=2 |volume=8 Birds I Tinamous and Ratites to Hoatzins |pages=95–98 |publisher=Gale Group |place=Farmington Hills, MI |isbn=0-7876-5784-0}}

Despite being geographically closer to the kiwi, phylogenetic analyses based on recovered DNA show moa to have been closest to the Central and South American tinamous. South island giant moa belong to the genus Dinornis, and are placed within their own family, Dinornithidae, along with their close relative Dinornis novaezealandiae from the North Island. These, along with the extinct upland moa and tinamous, are among the most basal palaeognaths.{{Citation needed|date=February 2025}}

The cladogram below follows a 2009 analysis by Bunce et al.:{{Cite journal | last1 = Bunce | first1 = M. | last2 = Worthy | first2 = T. H. | last3 = Phillips | first3 = M. J. | last4 = Holdaway | first4 = R. N. | last5 = Willerslev | first5 = E. | last6 = Haile | first6 = J. | last7 = Shapiro | first7 = B. | last8 = Scofield | first8 = R. P. | last9 = Drummond | first9 = A. | last10 = Kamp | doi = 10.1073/pnas.0906660106 | first10 = P. J. J. | last11 = Cooper | first11 = A. | title = The evolutionary history of the extinct ratite moa and New Zealand Neogene paleogeography | journal = Proceedings of the National Academy of Sciences | volume = 106 | issue = 49 | pages = 20646–20651 | year = 2009 | pmid = 19923428| pmc = 2791642| bibcode = 2009PNAS..10620646B | url = http://researchrepository.murdoch.edu.au/id/eprint/5109/1/extinct_ratite_moa.pdf | doi-access = free }}

{{clade| style=font-size:80%;line-height:80%

|label1=Dinornithiformes

|1={{clade

|1={{clade

|label1=Megalapteryidae

|1={{clade

|1=Megalapteryx didinus

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|label2=Dinornithidae

|2={{clade

|label1=Dinornis

|1={{clade

|1=D. robustus

|2=D. novaezealandiae

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|label2=Emeidae

|2={{clade

|label1=Pachyornis

|1={{clade

|1=P. australis

|2={{clade

|1=P. elephantopus

|2=P. geranoides

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|2={{clade

|1=Anomalopteryx didiformis

|2={{clade

|1=Emeus crassus

|2=Euryapteryx curtus

}}

}}

}}

}}

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The South Island giant moa was the largest species of moa. Adult females stood up to {{convert|2|metre|ftin}} tall at the back, and could reach foliage up to {{convert|3.6|metre|ftin}} off the ground, making them the tallest bird species known. Despite their great height, Dinornis robustus was found to have weighed only {{convert|200|kg|lbs}} on average, with upper estimates of around ≥{{convert|250|kg|lbs}} for females. Only one specimen of a complete or partially complete moa egg has been assigned to the South Island giant moa, found around Kaikōura. This egg, {{convert|240|mm|in}} in length and {{convert|178|mm|in}} in width, was the largest moa egg found in museum collections as of 2006.{{Cite Q|Q58623352}}

Very large-bodied, they had proportionately small heads, a trait found across all ratites. Analysis of their skull shows that they had somewhat poor eyesight due to their small orbits, rounded bills, and a very acute sense of smell thanks to a strongly developed olfactory system. Dinornis had thinner leg bones than other moa, indicating that they were more agile, though they likely moved slowly and cautiously. Unusually, giant moas were the only large ratites that sported a hallux (the first digit of the foot). Uniquely, the moa were essentially wingless; the only remnant of a wing was the scapulocoracoid bone, which, at one point earlier in its evolution, was where the humerus should have attached.{{Citation needed|date=February 2025}}

File:Dinornis robustus (AM LB723) 601381.jpg

Giant moas were likely fully feathered, except for their heads and a small portion of the neck, as well as the tarsus and feet. Feathers belonging to this species have been found, revealing that its plumage was plain brown or slightly streaked.{{cite web |last=Szabo |first=M.J. |orig-year=2013 |year=2022 |edition=updated |title=South Island giant moa |editor=Miskelly, C.M. |website=New Zealand Birds Online |url=https://nzbirdsonline.org.nz/species/south-island-giant-moa |access-date=28 July 2023}}

D. robustus, along with its relatives, were quite eccentric birds. Although they could reach 11+ feet in height, they mostly held their necks horizontally rather than vertically, like their distant relatives, the kiwi.{{Citation needed|date=February 2025}}

Moa most likely filled a diurnal role in their ecosystem, similar to that of emus.{{cite journal |last1=Ashwell |first1=Ken |last2=Scofield |first2=R. |year=2008 |title=Big birds and their brains: Paleoneurology of the New Zealand moa |journal=Brain, Behavior and Evolution |volume=71 |issue=2 |pages=151–166 |doi=10.1159/000111461|pmid=18032890 |s2cid=8334497 }}

Because New Zealand lacked any native terrestrial, herbivorous mammals, the moa filled that niche. Giant moas in particular are ecologically equivalent to giraffes and other long-necked plant-eating megafauna, though they lack any living analogues in New Zealand. These birds sported a very robust bill, and finds of a relatively large collection of gizzard stone for grinding food indicate a highly fibrous diet.{{Cite book |last=Tennyson |first=Alan J. D. |url=https://www.worldcat.org/oclc/80016906 |title=Extinct birds of New Zealand |date=2006 |publisher=Te Papa Press |others=Paul Martinson |isbn=978-0-909010-21-8 |location=Wellington, N.Z. |pages=24 |oclc=80016906}} Most foraging took place in forests and open fields, with fossilized coprolites revealing the diet of D. robustus to have included twigs, seeds, berries, leaves, flowers, vines, herbs, and shrubs. It's likely that this species fed on vegetation that was unable to be digested by other species, therefore avoiding competition with other grazers.{{cite news |last=Malory |first=Marcia |date=October 2013 |title=Scientists use fossilized feces to reconstruct moa diet |website=Phys.org |url=https://phys.org/news/2013-10-scientists-fossilized-feces-reconstruct-moa.html |access-date=2023-01-07 |lang=en}} Their bill would have allowed them to feed by means of cutting and breaking twigs and stems via lateral shaking. In addition to their bills, moas had stronger neck muscles than other ratite families, which might have given them a stronger pulling / tugging force.{{cite journal |last1=Attard |first1=M.R. |last2=Wilson |first2=L.A. |last3=Worthy |first3=T.H. |last4=Scofield |first4=P. |last5=Johnston |first5=P. |last6=Parr |first6=W.C. |last7=Wroe |first7=S. |date=2016-01-13 |title=Moa diet fits the bill: Virtual reconstruction incorporating mummified remains and prediction of biomechanical performance in avian giants |journal= Proceedings of the Royal Society B: Biological Sciences |volume=283 |issue=1822 |page=20152043 |doi=10.1098/rspb.2015.2043 |pmid=26763698 |pmc=4721086}} They also could have used their necks to reach higher vegetation, if necessary.{{Citation needed|date=February 2025}}

Giant moas were most likely long-lived birds which took many years to reach full maturity. Similar to cassowaries, females likely would have competed for males, seeing as they were much larger. It is likely that the males would have primarily reared the chicks, as the female would have been too large to incubate the weak-shelled eggs; however, their method of incubation is still unknown. They nested in rock shelters from late spring to early summer. Chicks are speculated to have been striped, like those of other ratites.{{Citation needed|date=February 2025}}

Dinornis robustus lived on the South Island of New Zealand as well as in Rakiura and Native Island, and its habitat was centered around the lowlands (shrubland, duneland, grassland, and forests).{{cite journal |last1=Verry |first1=Alexander J.F. |last2=Schmidt |first2=Matthew |last3=Rawlence |first3=Nicolas J. |date=15 November 2021 |title=A partial skeleton provides evidence for the former occurrence of moa populations on Rakiura Stewart Island |journal=New Zealand Journal of Ecology |volume=46 |issue=1 |pages=}}{{Cite journal |last1=Verry |first1=Alexander |last2=Schmidt |first2=Matthew |last3=Rawlence |first3=Nicolas |date=2021-01-31 |title=A partial skeleton provides evidence for the former occurrence of moa populations on Rakiura Stewart Island |url=http://dx.doi.org/10.20417/nzjecol.46.8 |journal=New Zealand Journal of Ecology |doi=10.20417/nzjecol.46.8 |issn=0110-6465 |s2cid=244026692}} Along with other members of the moa family, the South Island giant moa went extinct due to predation from humans in the 15th century, about 200 years after colonisation by the Māori.{{cite journal |last1=Perry |first1=George L.W. |last2=Wheeler |first2=Andrew B. |last3=Wood |first3=Jamie R. |last4=Wilmshurst |first4=J.M. |author4-link=Janet Wilmshurst |date=December 2014 |title=A high-precision chronology for the rapid extinction of New Zealand moa (Aves, Dinornithiformes) |journal=Quaternary Science Reviews |volume=105 |pages=126–135 |doi=10.1016/j.quascirev.2014.09.025 |bibcode=2014QSRv..105..126P }}

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• {{cite web

|last=Brands

|first=Sheila

|date=14 August 2008

|title=classification, genus Dinornis

|series=Systema Naturae 2000

|website=Project: The Taxonomicon (taxonomy.nl)

|url=http://www.taxonomy.nl/Main/Classification/51294.htm

|archive-url=https://archive.today/20071105045520/http://www.taxonomy.nl/Main/Classification/51294.htm

|url-status=dead

|archive-date=5 November 2007

|access-date=4 February 2009

}}

{{refend}}

• {{cite AV media |people=Martinson, Paul (artist) |year=2005 |medium=watercolor |title=South Island giant moa, Dinornis robustus |series=Extinct birds of New Zealand |url=https://collections.tepapa.govt.nz/object/710917 |via=Government of New Zealand |access-date=2023-03-24}} from
  {{cite book |author=Tennyson, Alan |year=2006 |title=Extinct Birds of New Zealand |place=Wellington, NZ |publisher=Te Papa Press}}

{{Birds of New Zealand}}

{{Portal bar|Birds|New Zealand|Paleontology}}

{{Taxonbar|from=Q3501588}}

South Island giant moa

Category:Birds of the South Island

Category:Holocene extinctions

Category:Extinct flightless birds

Category:Extinct birds of New Zealand

Category:Late Quaternary prehistoric birds

Category:Ratites

South Island giant moa