Dinornis

File:Dinornis robustus, South Island Giant Moa - three quarter view on black YORYM 2004 20.jpg

Dinornis may have been the tallest bird that ever lived, with the females standing around {{convert|3.6|m|ft|abbr=on}} tall,Wood, Gerald (1983) and weighing an estimated {{convert|230|-|240|kg|lb|abbr=on}}Amadon, D. (1947) or {{convert|278|kg|lb|abbr=on}}Campbell Jr., K. & Marcus, L. (1992) in various estimates. However, the males of the genus were much smaller, only around {{Convert|34-85|kg}}.{{Cite journal |last1=Olson |first1=Valérie A. |last2=Turvey |first2=Samuel T. |date=2013-06-07 |title=The evolution of sexual dimorphism in New Zealand giant moa ( Dinornis ) and other ratites |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=280 |issue=1760 |pages=20130401 |doi=10.1098/rspb.2013.0401 |issn=0962-8452 |pmc=3652460 |pmid=23576789}}

Feather remains are reddish brown and hair-like, and covered most of the body except the lower legs and most of the head (plus a small portion of the neck below the head). While no feathers have been found from moa chicks, it is likely that they were speckled or striped to camouflage them from Haast's Eagles.{{Cite book|title=Moa : the life and death of New Zealand's legendary bird|last=Berentson, Quinn.|date=2012|publisher=Craig Potton|isbn=9781877517846|location=Nelson, N.Z.|oclc=819110163}}

The feet were large and powerful, and could probably deliver a powerful kick if threatened. The birds had long, strong necks and broad sharp beaks that would have allowed them to eat vegetation from subalpine herbs through to tree branches. In relation to its body, the head was small, with a pointed, short, flat and somewhat curved beak.{{Citation needed|date=February 2025}}

The North Island giant moa tended to be larger than the South Island giant moa.

The cladogram below follows a 2009 analysis by Bunce and colleagues:{{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 = 20646–51 | year = 2009 | pmid = 19923428| pmc = 2791642| bibcode = 2009PNAS..10620646B | doi-access = free }}

{{clade| style=font-size:90%;line-height:80%

|label1=Dinornithiformes

|1={{clade

|1={{clade

|label1=Megalapteryidae

|1={{clade

|1=Megalapteryx didinus

}}

|label2=Dinornithidae

|2={{clade

|label1=Dinornis

|1={{clade

|1=D. robustus

|2=D. novaezealandiae

}}

}}

}}

|label2=Emeidae

|2={{clade

|label1=Pachyornis

|1={{clade

|1=P. australis

|2={{clade

|1=P. elephantopus

|2=P. geranoides

}}

}}

|2={{clade

|1=Anomalopteryx didiformis

|2={{clade

|1=Emeus crassus

|2=Euryapteryx curtus

}}

}}

}}

}}

}}

File:Dinornis size.png

It has been long suspected that several species of moa constituted males and females, respectively. This has been confirmed by analysis for sex-specific genetic markers of DNA extracted from bone material.Huynen, L. J.,et al. (2003) For example, prior to 2003 three species of Dinornis were recognised: South Island giant moa (D. robustus ), North Island giant moa (D. novaezealandiae) and slender moa (D. struthioides). However, DNA analysis showed that all D. struthioides were in fact males, and all D. robustus were females. Therefore, the three species of Dinornis were reclassified as two species, one each formerly occurring in New Zealand's North Island (D. novaezealandiae) and South Island (D. robustus); However, D. robustus comprises three distinct genetic lineages and may eventually be split into more than one species. Dinornis seems to have had the most pronounced sexual dimorphism of all moa, with females being up to twice as tall and three times as heavy as males.

File:Dinornis struthoides.jpg

While it is impossible to know exactly how Dinornis reproduced and raised young, assumptions can be made from extant ratites. The larger females may have competed to mate with the most desirable males who themselves were likely to have been extremely territorial. Eggs may have been laid in communal nests in sand dunes, or by individual birds in sheltered environments such as hollow trees or by rocks. The female would have had little to do with the eggs once they had been laid while the male would have incubated the egg for up to three months before it hatched.{{Citation needed|date=February 2025}}

Dinornis eggs were enormous, as large as a rugby ball, and around 80 times the volume of a chicken's egg. However, despite their size, Dinornis eggs were extremely thin, with the eggshells of D. novaezealandiae being only around 1.06 millimeters (0.04 inches) thick and D. robustus' eggshells being 1.4 millimeters (0.06 inches) thick. As such, Dinornis eggs have been estimated to be the 'most fragile of all avian eggs measured to date'.{{Cite journal|last1=Huynen|first1=L.|last2=Gill|first2=B. J.|last3=Millar|first3=C. D.|last4=Lambert|first4=D. M.|date=2010-08-30|title=Ancient DNA reveals extreme egg morphology and nesting behavior in New Zealand's extinct moa|journal=Proceedings of the National Academy of Sciences|volume=107|issue=37|pages=16201–16206|doi=10.1073/pnas.0914096107|pmid=20805485|issn=0027-8424|pmc=2941315|bibcode=2010PNAS..10716201H|doi-access=free}}

It is possible that such fragile eggs resulted in the male moa adapting to become smaller than the females to reduce the risk of crushing the eggs. However, it is possible that the male moa would curl themselves around the eggs rather than sitting on them directly. Given the size of the eggs, and the incubation period, as soon as giant moa chicks hatched they would have been able to see, run and feed themselves.

Dinornis were very adaptable and were present in a wide range of habitats from coastal to alpine. It is possible that individual moa would have moved from environment to environment with the changing seasons.{{Citation needed|date=February 2025}}

Prior to the arrival of humans, the giant moa had an ecologically stable population in New Zealand for at least 40,000 years. The giant moa, along with other moa genera, were wiped out by Polynesian settlers,{{cite web| url= https://www.sciencedaily.com/releases/2012/08/120803114412.htm | title= Giant Moa Had Climate Change Figured out| publisher= ScienceDaily | date= August 3, 2012| access-date=2012-08-06 }} who hunted it for food. All taxa in this genus were extinct by the year 1500. It is generally accepted that the Māori still hunted them at the beginning of the fifteenth century, although some models suggest extinction had already taken place by the middle of the 14th century.{{cite journal|last1=Holdaway|first1=R. N.|last2=Jacomb|first2=C.|year=2000|title=Rapid Extinction of the Moas (Aves: Dinornithiformes): Model, Test, and Implications|journal=Science|volume=287|issue=5461|pages=2250–2254|doi=10.1126/science.287.5461.2250|pmid=10731144|bibcode=2000Sci...287.2250H}} Although some birds became extinct due to farming, for which the forests were cut and burned down and the ground was turned into arable land, the giant moa had been extinct for 300 years prior to the arrival of European settlers.{{cite journal|last1=Perry|first1=G. L.|last2=Wheeler|first2=A. B.|last3=Wood|first3=J. R.|last4=Wilmshurst|first4=J. M.|year=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}}

;Specific citations

{{Reflist}}

;General references

{{refbegin|2|indent=yes}}{{cite journal|last=Amadon|first=D.|year=1947|title=An estimated weight of the largest known bird|journal=Condor|volume=49|issue=4|pages=159–164|doi=10.2307/1364110|jstor=1364110}}

:{{cite journal|last1=Baker|first1=Allan J.|last2=Huynen|first2=Leon J.|last3=Haddrath|first3=Oliver|last4=Millar|first4=Craig D.|last5=Lambert|first5=David M.|year=2005|title=Reconstructing the tempo and mode of evolution in an extinct clade of birds with ancient DNA: The giant moas of New Zealand|journal=Proceedings of the National Academy of Sciences|volume=102|issue=23|pages=8257–8262|pmid=15928096|pmc=1149408|doi=10.1073/pnas.0409435102|bibcode=2005PNAS..102.8257B|url=http://www.pnas.org/content/102/23/8257.full.pdf|access-date=Feb 14, 2011|doi-access=free}}

:{{cite book|last1=Benes|first1=Josef|title=Prehistoric Animals and Plants|year=1979|publisher=Hamlyn|location=London, UK|isbn=978-0-600-30341-1|page=191}}

:{{Cite book|title=Moa: The Life and Death of New Zealand's Legendary Bird|last=Berentson|first=Quinn|publisher=Craig Potton Publishing|year=2012|isbn=9781877517846}}

:{{cite journal|last1=Bunce|first1=Michael|last2=Worthy|first2=Trevor H.|last3=Ford|first3=Tom|last4=Hoppitt|first4=Will|last5=Willerslev|first5=Eske|last6=Drummond|first6=Alexei|last7=Cooper|first7=Alan|year=2003|title=Extreme reversed sexual size dimorphism in the extinct New Zealand moa Dinornis|journal=Nature|volume=425|issue=6954|pages=172–175|pmid=12968178|doi=10.1038/nature01871|bibcode=2003Natur.425..172B|s2cid=1515413}}

:{{cite journal|last1=Campbell, Jr.|first1=K. E.|last2=Marcus|first2=L.|year=1992|title=The relationship of hindlimb bone dimensions to body weight in birds|journal=Papers in Avian Paleontology Honoring Pierce Brodkorb|series=Science|issue=36|pages=395–412}}

:{{Cite journal|last1=Huynan|first1=Leon|last2=Gill|first2=Brian J.|last3=Millar|first3=Craig D.|last4=Lambert|first4=David M.|year=2014|title=Ancient DNA Reveals Extreme Egg Morphology and Nesting Behavior in New Zealand's Extinct Moa|url=https://www.pnas.org/content/107/37/16201|journal=Proceedings of the National Academy of Sciences|volume=107|issue=37}}

:{{cite journal|last1=Huynen|first1=Leon J.|last2=Millar|first2=Craig D.|last3=Scofield|first3=R. P.|last4=Lambert|first4=David M.|year=2003|title=Nuclear DNA sequences detect species limits in ancient moa|journal=Nature|volume=425|issue=6954|pages=175–178|pmid=12968179|doi=10.1038/nature01838|bibcode=2003Natur.425..175H|s2cid=4413995}}

:{{cite journal|last1=Owen|first1=Richard|year=1843|title=On the remains of Dinornis, an extinct gigantic struthious bird|journal=Proceedings of the Zoological Society of London|pages=8–10, 144–146}}

:{{cite book|author=Wood, Gerald|url=https://archive.org/details/guinnessbookofan00wood|title=The Guinness Book of Animal Facts and Feats|publisher=Sterling Publishing Company Inc.|edition=3rd|year=1983|isbn=978-0-85112-235-9|url-access=registration}}{{refend}}

{{commons category|Dinornis}}

{{Portal|Paleontology}}

• [http://collections.tepapa.govt.nz/objectdetails.aspx?oid=710917 South Island Giant Moa. Dinornis robustus.] by Paul Martinson. Artwork produced for the book Extinct Birds of New Zealand, by Alan Tennyson, Te Papa Press, Wellington, 2006

• [https://www.aucklandmuseum.com/discover/collections/topics/tale-of-the-giant-moa Tale of the giant moa] by Matt Rayner and Andrea Stevens. Auckland War Memorial Museum - Tāmaki Paenga Hira. First published: 23 November 2015. Updated: 12 November 2019.

{{Palaeognathae|N.}}

{{Taxonbar|from=Q899705}}

Category:Dinornithinae

Category:Holocene extinctions

Category:Ratites

Category:Bird genera

Category:Extinct birds of New Zealand

Category:Taxa named by Richard Owen

Category:Fossil taxa described in 1843

Category:Species that are or were threatened by use as food