Pachyornis mappini

Geographic Range

Mappin's moas were endemic to the North Island of New Zealand.

• Biogeographic Regions
• australian australian
  • native native
• oceanic islands oceanic islands
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Mappin's moas were widespread throughout North Island habitats such as open forests, scrublands, and grasslands.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest

Physical Description

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.

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.

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.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

Reproduction

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.

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.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

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.

• Parental Investment
• precocial precocial
• male parental care male parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
• pre-weaning/fledging
  • protecting
    • male

Lifespan/Longevity

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.

Behavior

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.

• Key Behaviors
• terricolous
• diurnal diurnal
• motile motile
• sedentary sedentary

Communication and Perception

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.

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

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.

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • granivore granivore
  • lignivore

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• fruit

Predation

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.

Ecosystem Roles

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.

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.

Economic Importance for Humans: Positive

All species of moas were major food sources for the Polynesian settlers of New Zealand, ultimately resulting in their being hunted to extinction.

• Positive Impacts
• food food
• body parts are source of valuable material

Economic Importance for Humans: Negative

There are no known adverse affects of Pachyornis mappini on humans.

Conservation Status

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.

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Keenan Bailey (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

References

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.