The iconic moa of New Zealand were giant flightless endemic birds grouped in three families, six genera and nine species. They evolved into a wide variety of sizes to become the largest terrestrial herbivores in prehistoric New Zealand. Together they represent the most diverse radiation of any New Zealand endemic bird group, ranging from the small little bush moa to the two giant moa species of the South and North Islands. The nine moa species occurred across a variety of habitat types. All the moa species became extinct abruptly, 500-600 years ago, as a result of human overhunting. DNA study suggests that moa were more closely related to the flighted South American tinamou than to the kiwi.

The little bush moa was the smallest and most widespread moa species, occurring in forest throughout the North and South Islands. Slender with relatively long legs, it inhabited dense forest and shrubland. It was the only species in the genus Anomalopteryx. Its relatively short, sharp-edged bill appears to have been more suited to cutting than those of other moa species. This attribute and the large number of stones typically found in the bird's gizzard, suggest that it had a woody, fibrous diet. It appears to have lived singly or in small groups at a suggested density of one pair per square kilometre. It was probably preyed on by both Haast's eagle and Eyles' harrier in the South Island, and the larger Eyles' harriers of the North Island. Its bone remains are common in archaeological sites near Wellington and Nelson, indicating that it was hunted for food.

Identification

The little bush moa was turkey-sized, lightly-built, with a rounded head, a short, stubby, rounded bill, and relatively slender legs. Its legs were bare and scaly, and it had shaggy hair-like body feathers.

Similar species: size closest to Mantell's moa.

Distribution and habitat

Little bush moa occurred throughout the North and South Islands in closed-canopy lowland forest. They were most abundant in the North Island. Remains in the South Island have mainly been found in north-west Nelson and Southland.

Population

Little bush moa remains are common in some archaeological sites near Wellington and Nelson, indicating that it was at least locally common.

Threats and conservation

The main cause of extinction was overhunting by humans for food. Moa chicks may also have been eaten by the introduced Polynesian dog (kuri).

Breeding

Field research and DNA study suggests moa nests were similar to those of Australian emu and cassowary, and were built on the ground or in rock shelters. Little bush moa nests have been found in rock shelters in the North Island. Limited evidence suggests moa bred in solitary pairs, rather than colonies, the female laying probably one or two eggs per breeding season. The relatively large eggs (likely to have been about 165 x 119 mm) in comparison with body size suggest a long incubation period, probably exceeding two months. The male is thought to have incubated the eggs, as is the case for most other ratites.

Behaviour and ecology

Little bush moa lived in wet rainforests, and were probably preyed on by both Haast's eagle (South Island only) and Eyles' harrier. They probably took up to eight years to reach adult size.

Food

The sturdy, sharp-edged bill suggests that little bush moa browsed on twigs and other tough plant material.

Weblinks

Wikipedia

References

Anderson, A. 1989. Prodigious birds: moas and moa-hunting in prehistoric New Zealand. Cambridge University Press, Cambridge, UK.

Baker, A. J.; Haddrath, O.; McPherson, J. D.; and Cloutier, A. 2014. Genomic support for a moa-tinamou clade and adaptive morphological convergence in flightless ratites. Molecular Biology and Evolution, Vol 31, Issue 7: 1686-1696.

Bunce, M.; Worthy, T.H.; Phillips, M.J.; Holdaway, R.N.; Willersley, E.; Haile, J.; Shapiro, B.; Scofield, R.P.; Drummond, A.; Kamp, P.J.J.; Cooper, A. 2009. The evolutionary history of the extinct ratite moa and New Zealand neogene paleogeography. Proceedings of the National Academy of Sciences USA 106: 20646-20651.

Gill, B.J. 2007. Eggshell characteristics of moa eggs (Aves: Dinornithiformes). Journal of the Royal Society of New Zealand 37: 139-150.

Gill, B.; Martinson, P. 1991. New Zealand's extinct birds. Random Century, New Zealand.

Huynen, L.; Gill, B.J.; Millar, C.D.; Lambert, D.M. 2010. Ancient DNA reveals extreme egg morphology and nesting behavior in New Zealand’s extinct moa. Proceedings of the National Academy of Sciences (PNAS) 107: 16201-16206.

Phillips, M.J.; Gibb, G.C.; Crimp, E.A.; Penny, D. 2010. Tinamous and moa flock together: mitochondrial genome sequence analysis reveals independent losses of flight among ratites. Systematic Biology 59: 90-107.

Rawlence, N.J.; Wood, J.R.; Armstrong, K.N.; Cooper, A. 2009. DNA content and distribution in ancient feathers and potential to reconstruct the plumage of extinct avian taxa. Proceedings of the Royal Society. B 7 (1672): 3395-3402.

Szabo, M. 2005. Hobbit-sized raptor became 'Lord of the Wings'. Forest & Bird, May 2005, Issue 316: 12.

Szabo, M. 2006. Extinct birds of New Zealand: a preview. Forest & Bird, November 2006, Issue 322: 22-24.

Tennyson, A.; Martinson, P. 2006. Extinct birds of New Zealand. Te Papa Press, Wellington.

Tennyson, A.J.D. 2010. Dinornithiformes. Pp. 11-18. In: Checklist Committee (OSNZ) Checklist of the birds of New Zealand, Norfolk and Macquarie Islands, and the Ross Dependency, Antarctica (4th ed.). Ornithological Society of New Zealand & Te Papa Press, Wellington.

Wood, J.R. 2008. Moa (Aves: Dinornithiformes) nesting material from rockshelters in the semi-arid interior of South Island, New Zealand. Journal of the Royal Society of New Zealand 38: 115-129.

Wood, J.R.; Wilmshurst, J.M.; Wagstaff, S.J.; Worthy, T.H.; Rawlence, N.J.; Cooper. A. 2012. High-resolution coproecology: using coprolites to reconstruct the habits and habitats of New Zealand’s extinct upland moa (Megalapteryx didinus). PLoS ONE 7: e40025.

Worthy, T.H.; Holdaway, R.N. 2002. The lost world of the moa: prehistoric life in New Zealand. Canterbury University Press, Christchurch.

Worthy, T.H.; Scofield, R.P. 2012. Twenty-first century advances in knowledge of the biology of moa (Aves: Dinornithiformes): a morphological analysis and diagnosis revised. New Zealand Journal of Zoology 39: 87-153.

Recommended citation

Szabo, M.J. 2013 [updated 2022]. Little bush moa | moariki. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz