Mappin's moas were large ratites, with a height to the shoulder of approximately 67 cm and a head height that reached about 97 cm. Female moas in the genus Dinornis could be significantly larger than their male counterparts, which may have been true of Pachyornis species as well. (Anderson, 1989; Turvey, et al., 2005)
A fascinating feature of all moas was that they did not have wings, not even vestigial remnants. It is also interesting to note that moas took much longer than extant birds to reach adult body size, with development periods ranging from three to nine years. (Anderson, 1989; Turvey, et al., 2005)
The bill of Pachyornis elaphatopus closely resembles that of Pachyornis mappini and features a deeply grooved and pointed mandible. This characteristic of all members of the genus Pachyornis suggests that they may have had the most powerful cutting mandibles of any moa. (Anderson, 1989; Turvey, et al., 2005)
Since all species of moas are extinct it is impossible to be certain of mating behaviors. However, similar ratites such as emus allow us to make inferences about moa mating systems. Emu males maintain territories, compete with other males, and display to attract mates. Male emus mate exclusively with one female for a season. During this period the female lays the eggs and the male incubates them over the winter. (Anderson, 1989)
General reproductive behavior is difficult to determine since all species of moa were extinct prior to European discovery of New Zealand. Nest findings suggest moas laid one egg per season, which may have been incubated over the course of the winter. Compared to extant ratites, moas took a long time to reach sexual maturity. The growth period of moas could extend from as few as three years to as many as nine years, reaching sexual maturity in as long as 5 years. (Anderson, 1989; Diamond, 2000; Turvey, et al., 2005)
Since moa behavior cannot be observed in the wild, inferences on parental investment must be based on extant ratites. Male emus <<Dromaius>. incubate eggs that have been layed by the female over the course of the winter, remaining on the nest except to eat and drink. After the eggs hatch, the precocial young accompany the male while foraging until they approach maturity. (Anderson, 1989)
Before humans began hunting moas they had no natural predators. This lack of predation probably contributed to their long lifespan of over 30 years. Survivorship increased as moas aged and grew, as they could browse for food throughout their height range. (Anderson, 1989)
Since all species of moa are extinct, there is little data on their behavior. Other, large ratites are proficient at moving about land quickly, however it is thought that moas traveled only tens of kilometers throughout their lifetimes. Moas were specialized for eating woody, fibrous material low in nutrition, requiring them to forage almost constantly. (Anderson, 1989)
Since all species of moas are extinct, it is unclear how they communicated. Other large ratites may offer comparison. It is possible that moas used vocal communication in order to attract mates. The evolution of mimicry among plants that were subject to moa herbivory suggests that moas used vision to find food plants. (Anderson, 1989; Atkinson and Greenwood, 1989)
Based on the gizzard content of subfossil moas, it appears that they ingested stones and pebbles to help digest the seeds, twigs, fruit, and leaves that they ate. Moas were not well adapted to toxins in plants; they relied more heavily on eating fibrous materials such as twigs, rather than fruits and leaves which held more of the anti-herbivory defense mechanisms. Surviving on less poisonous, less nutritious, fibrous foods required moas to have a diverse, high volume diet. (Anderson, 1989)
Other than humans, there are no known predators for any species of moa. In fact, there was little competition that faced moas prior to human settlement in New Zealand.
There is evidence of a coevolutionary relationship between moas and the plants that they ate. Moa food plants developed physical defenses and mimicry to avoid predation. Chemical defenses also evolved in some plants as a way to reduce herbivory from moas, other plants developed systems of mimicry to emulate the appearance of plants that moas would not eat. The use of spines as a defense against grazing is used among Aciphylla plants, with populations of these plants having reduced spines in areas that would have been inaccessible to moas. (Atkinson and Greenwood, 1989)
The height of moas also contributed to the roles that they played in their ecosystem. Since the moas could browse for food throughout their height range, trees and other woody plants had selection pressure to grow large enough, quickly enough, so that all of the saplings would not be decimated by the continuously browsing moas. (Atkinson and Greenwood, 1989)
All species of moas were major food sources for the Polynesian settlers of New Zealand, ultimately resulting in their being hunted to extinction. (Diamond, 2000)
There are no known adverse affects of Pachyornis mappini on humans.
Pachyornis mappini went extinct after the colonization of New Zealand by humans. Polynesian islanders began colonizing the islands of New Zealand in the 13th century A.D. and hunted P. mappini to extinction by the time European explorers first arrived in 1642 A.D. It is suggested that these moas were hunted to extinction within one hundred years of human colonization since moas were easy prey and took nearly five years to reach reproductive maturity. (Diamond, 2000; Holdaway and Jacomb, 2000)
Tanya Dewey (editor), Animal Diversity Web.
Keenan Bailey (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
uses sound to communicate
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
animals that live only on an island or set of islands.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
parental care is carried out by males
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
young are relatively well-developed when born
Anderson, A. 1989. Prodigious Birds: Moas and moa-hunting in prehistoric New Zealand. Cambridge: Press Syndicate of the University of Cambridge.
Atkinson, I., R. Greenwood. 1989. Relationships between Moas and Plants. New Zealand Journal of Ecology, 12: 67-96.
Baker, A., L. Huynen, O. Haddrath, C. Millar, D. Lambert. 2005. Reconstructing the tempo and mode of evolution in an extinct clade of birds with ancient DNA: The giant moas of New Zealand. Proceedings of the National Academy of Sciences of the United States of America, 102. Accessed October 16, 2006 at http://www.pnas.org/.
Diamond, J. 2000. Blitzkrieg Against the Moas. Science, 287: 2170-2171.
Holdaway, R., C. Jacomb. 2000. Rapid Extinction of the Moas (Aves:Dinornithiformes): Model, Test, and Implications. Science, 287: 2250-2251.
McGlone, M. 1989. The Polynesian settlement of New Zealand in relation to environmental and biotic changes. New Zealand Journal of Ecology, 12: 115.
Smuts-Kennedy, C., K. Collier, B. Clarkson, B. Burns, R. MacGibbon. 2004. "An ecological restoration plan for Maungatautari" (On-line pdf). Maungatautari Ecological Island Trust. Accessed November 12, 2006 at http://www.maungatrust.org/pdfs/restoration_plan_Nov_04.pdf.
Turvey, S., O. Green, R. Holdaway. 2005. Cortical growth marks reveal extended juvenile development in New Zealand moa. Nature, 435: 940-943.