“The moa was a big flightless bird in New Zealand that went extinct.” So goes the everyday short version of the story of the moa. But there’s more. Like all things in life, the scenario is not as simple as it seems.
For a start, here were a number of different moas. Many people are unaware of the fact that there were at least nine species of moas from six genera, so they were possibly quite different birds, with the similarities being they could not fly, were all vegetarians, and all lacked any vestige of wing bones, suggesting an ancient evolution on the ground. There are an additional two un-named species of moa.
The nine species of moa were the upland moa, the little bush moa, the heavy-footed moa, Mantell’s moa, crested moa, eastern moa, stout-legged moa, North Island giant moa, and the South Island giant moa. That they all are extinct now is beyond question. No-one has seen a moa since around 500-600 years ago. Or from our perspective looking back in history, in the 15th century. That’s after the discovery of Aotearoa by Polynesian ocean voyagers, and their introduction of the dog and the rat.
But maybe not - see below.
It’s clear the abrupt extinction of all the moa species must have been the result of over-hunting by humans, and, possibly, predation on the chicks by dogs. Archaeological evidence in the form of moa remains in middens, and specialised tools for cutting up moa carcasses and for forming moa bones into tools, contributes to that conclusion. In the natural order of things, most species of moa (except perhaps the North and South Island giant moas) were preyed upon by the giant Haast’s eagle and Eyle’s harrier, both also now extinct.
The upland moa (Megalapteryx didinus) was quite small, and lived in the mountains. DNA analysis of their remains show the upland moa was most closely related to a South American bird called the tinamou. It was found only in the South Island in the sub-alpine region. It had feathers on its legs and its toes were adapted for walking in the snow. The upland moa nested in rock shelters.
The little bush moa (Anomalopteryx didiformis) was the smallest and most widespread species, about the size of a big chicken, and found in the forest on both North and South Islands. They would take about eight years to reach full size.
The heavy-footed moa (Pachyornis elephantopus) was found in the eastern lowlands of the South Island, and appears to have been adapted to operate something like a bulldozer in the wetlands. It was the heaviest moa, and like its name suggest, had enormous feet and legs. It had an acute sense of smell, and was probably nocturnal.
Mantell’s moa (Pachyornis geranoides) was found in the North Island and on Aotea Great Barrier Island. It was around turkey-size and found in lowland wetlands and dunelands. I’m wondering if any remains were ever found on this island. A tantalising prospect. It turns out that in 2011, a boy from the primary school called Chris Anderson found a moa’s lower leg bone, scuffed from tumbling in the sand, at Onetangi Beach. But as yet, I haven’t turned up any evidence of moa bones being found in Waiheke middens.
The crested moa (Pachyornis australis) was a big, heavy bird with a tuft of feathers on it head. Their remains have been found in high altitude central South Island locations, and coastal dunes in Southland.
The eastern moa (Emeus crassus) was medium-sized and common in the eastern parts of the South Island. Females were 15-20% bigger than males, but only the males had elongated windpipes that suggest they had loud mating calls. Burning of its forest habitat may have also contributed to its demise.
The stout-legged moa (Euryapteryx curtus) is placed in its own genus. It was found throughout the country, Aotea Great Barrier Island included, but with quite a size difference between those in the far north (smallest) and those in the far south (biggest). The stout-legged moa occupied lowland coastal forest, and also some drier sites. Its diet was fruits and leaves, rather than the fibrous and woody material favoured by the giant moas.
The giant moas are what is probably most fixed in people’s minds. Lots of food for early hunters. The North Island giant moa (Dinornis novaezealandiae) was relatively common, tall and slender. Remains have also been found on Aotea Great Barrier island. The giant moas showed a marked sexual dimorphism, with the female birds being much bigger. An egg found near Waitomo shows that it could have weighed around three kilos when fresh. The South Island giant moa (Dinornis robustus) was the mainland cousin, with remains also found on Stewart and D’Urville islands. Both giant moa species had three extra neck vertebrae, compared to the rest of the moas. The giant moas were about 3.6m tall when stretched up, and could have weighed up to 230kg.
Some flightless birds have survived the human onslaught in Aotearoa. There are five species of kiwi (with one extinct), takahē, kākāpō – all now endangered – and the indomitable weka. The last is still fairly common, probably because they (apparently) don’t taste so good.
New Zealand would be an extra extra-ordinary environment if there were still moas about. Imagine!
Well, you can, because a wee book my mate Rob lent me, provocatively titled Which Pākehā Ate the Last Moa? by Rhys Richards, recounts European-era sightings and cookings of moa. Some credible, some not quite so. My favourites were the reports of a bright blue moa, feathered, I imagine like the Australian cassowary. Anyway, despite his accounts of later sightings, Richards does concede the moas, definitely, are all extinct now.
But the inevitable story of hunters not looking far enough forward to keep some stocks for future reference, points to an unfortunate human characteristic. Take what you can now, forget about the future consequences. Let’s hope that in future dealings with the wildlife we have left in this country – and that under the sea – we will be a bit more careful. That the story of the moas could teach us to whoa!