The giant moa (''Dinornis'') is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
genus of birds belonging to the
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 refer ...
family. As with other
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 refer ...
, it was a member of the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Dinornithiformes
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 refer ...
. It 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 elsew ...
to
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 ...
. Two species of ''Dinornis'' are considered valid, the
North Island giant moa
The North Island giant moa (''Dinornis novaezealandiae'') is an extinct moa in the genus ''Dinornis''. Even though it might have walked with a lowered posture, standing upright, it would have been the tallest bird ever to exist, with a height ...
(''Dinornis novaezealandiae'') and the
South Island giant moa
The South Island giant moa (''Dinornis robustus'') is an extinct moa from the genus ''Dinornis.''
Context
The moa were Ratite, ratites, flightless birds with a sternum without a Keel (bird anatomy), keel. They also had a distinctive palate. T ...
(''Dinornis robustus''). In addition, two further species (new lineage A and lineage B) have been suggested based on distinct DNA lineages.
Description
''Dinornis'' may have been the tallest bird that ever lived, with the females of the largest species standing tall,
[Wood, Gerald (1983)] and one of the most massive, weighing
[Amadon, D. (1947)] or
[Campbell Jr., K. & Marcus, L. (1992)] in various estimates.
Feather
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...
remains are reddish brown and
hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...
-like, and apparently 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.
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
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic character ...
from
subalpine
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 ...
herbs
In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...
through to tree branches.
In relation to its body, the head was small, with a pointed, short, flat and somewhat curved beak.
The North Island giant moa tended to be larger than the South Island giant moa.
Taxonomy
The
cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
below follows a 2009 analysis by Bunce ''et al.'':
Habitat
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.
Palaeobiology
Sexual dimorphism
![Dinornis struthoides](https://upload.wikimedia.org/wikipedia/commons/4/41/Dinornis_struthoides.jpg)
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 there were three species of ''Dinornis'' recognised: South Island giant moa (''D. robustus ''), North Island giant moa (''D. novaezealandiae'') and slender moa (''D. struthioides''). However, DNA 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
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 ...
's North Island (''D. novaezealandiae'') and South Island (''D. robustus '');
''robustus'' however, comprises three distinct genetic lineages and may eventually be classified as many 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.
Reproduction
While it is impossible to know exactly how ''Dinornis'' reproduced and raised young, assumptions can be made from
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
ratites
A ratite () is any of a diverse group of flightless, large, long-necked, and long-legged birds of the infraclass Palaeognathae. Kiwi, the exception, are much smaller and shorter-legged and are the only nocturnal extant ratites.
The systematics o ...
.
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.
''Dinornis'' eggs were enormous, as large as a
rugby ball
A rugby ball is an elongated ellipsoidal ball used in both codes of rugby football. Its measurements and weight are specified by World Rugby and the Rugby League International Federation, the governing bodies for both codes, rugby union and rugby ...
, and around 80 times the volume of a chicken's egg.
However, despite their size, Dinornis eggs were extremely thin, with ''D. novaezealandiae's'' eggshells being 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'.
It is possible that such fragile eggs resulted in the male moa adapting to become smaller in size 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.
Extinction
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,
who hunted it for food. All taxa in this genus were extinct by 1500 in New Zealand. It is generally accepted that the
Māori
Māori or Maori can refer to:
Relating to the Māori people
* Māori people of New Zealand, or members of that group
* Māori language, the language of the Māori people of New Zealand
* Māori culture
* Cook Islanders, the Māori people of the C ...
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.
Although some birds became extinct due to
farming
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
, for which the forests were cut and burned down and the ground was turned into
arable land
Arable land (from the la, arabilis, "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for the ...
, the giant moa had been extinct for 300 years prior to the arrival of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
an settlers.
References
;Specific citations:
;General references
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External links
''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
Tale of the giant moaby Matt Rayner and Andrea Stevens. Auckland War Memorial Museum - Tāmaki Paenga Hira. First published: 23 November 2015. Updated: 12 November 2019.
{{Taxonbar, from=Q899705
Dinornithinae
Holocene extinctions
Ratites
Bird genera
Extinct birds of New Zealand
Taxa named by Richard Owen
Fossil taxa described in 1843