By Virginia Winder

Richard Cassels stands in a graveyard of moa bones on a South Taranaki beach puzzling at the sight before him.

The archaeologist's mind is over-flowing with questions: What happened here? Why are there so many bones? Was this a hunting ground? A cooking area? How old are the bones? Are they from the same segment of time? What does it all mean?

Like a detective, he begins piecing together what actually happened at Kaupokonui to create one of New Zealand's most significant archaeological finds of the 20th century.

First, let's paint a picture of the scene he is facing. Imagine it's winter 1974 and your feet are planted in black-diamond sand, which turns into biting grains whipped by a westerly wind.

All around you are the white-cream husks of moa, fur seals, a sealion, a small whale and dogs. These are the large bones.

Look closely, and you will spy drifts of tiny fragments; the telltale signs of small birdlife.

The species list compiled by the study team, was huge.

Mind-blowing dig

Among the remains were a number of now-extinct birds, including the native goose; the huia, whose black-and-white feathers were prized for Maori cloaks; the giant rail, which was larger than a turkey and flightless; and of course the huge, muscular moa.

"There was this mass of bones," Cassels says. "When you looked carefully at what was underfoot, it was mind blowing."

Cassels is talking on the phone from Australia, where he works as director of exhibitions and publications for the Queensland Museum.

Even though the Kaupokonui site is across the Tasman Sea and the dig nearly 30 years ago, he has clear memories of the few winter-raw weeks spent fossicking among the leftovers of lost lives.

Kaupokonui Beach: Close to the Taranaki beach is an ancient moa hunting site.

This 1974 expedition was the second excavation of the Kaupokonui site. The first was conducted in the 1960s by Hawera doctor Alastair Buist. The amateur archaeologist was the one who called the university down for the later study, after discovering a storm had uncovered a whole lot more bones.

Racing time

"Every time there was a strong wind, more came out," Cassels says.

Once exposed to the elements on the wild Taranaki coast, the large bones would only last for about a month. "That stinging sand destroys them quite fast."

Backed by a team of eight from the University of Auckland's anthropology department Cassels faced a race against time.

With painstaking care, the pre-history scholars swiftly sifted the sand for ancient treasure and packed up bones for their journey to Auckland. There, they were dried out, hardened by chemicals, identified and carbon-dated.

The bones, which represented about 70 individual moa, are now in the Puke Ariki collection in New Plymouth.

Cassels believes they were just the tip of the iceberg. "There must have been hundreds."

Excavate – and out!

He blames the skeletal depletion on storms, amateur collectors and floods from the river below. However, there is a chance much more still lie hidden beneath the sand at that secret spot because the team only managed to excavate a quarter of the area.

You see, the university group was only allowed one bite at the site – a request to return the following year was turned down by the local iwi, Nga Ruahinerangi.

"We came down to do a second season and met a number of people and at that point they said they didn't want us to work on the site anymore. They didn't want anymore disturbance. That was the end of the excavation. I was very disappointed, but I understood. Those are not my ancestors, they are their ancestors."

There used to be a Maori village on a hill above the dunes, Cassels says.

Kill and cook

The valley below had been used for food preparation. "When we looked at the small and large bones, it was quite obvious there had been quite a lot of cooking going on, on the site."

And more gruesome acts. "It's a very spectacular example of a moa-hunting site. Most of the big moa-hunting sites had been excavated in the South Island in the 1800s. There are very few in the North Island."

Cassels says the site was of international interest because of the debate about what had made some species extinct – natural causes or pre-historic overkill.

"I think there was no doubt it was the effect of human settlement," Cassels says.   

"What our excavations did show was that there clearly were some big hunts because we found scattered around, moa bits and dog bodies scattered around ovens. They looked contemporary."

Dating the bones

Cassels says carbon dating, which always uses 1950 as the starting point, showed three main periods of hunting 100 years apart, going backwards in time from 450 years ago.

"The date for the moa hunting at Kaupokonui is in the early 1300s. Rather surprisingly, other large moa-hunting sites in the country have produced similar dates – all several hundred years later than the first settlement of New Zealand by Polynesians.

"Kaupokonui showed there was a lot of hunting. These are big birds that take a long time to grow up. Once you started hunting them it's very easy to over-hunt them."

While the early Maori would have tracked down the big birds, it's likely their dogs would have also played a role.

Gone to the dogs

"I think a moa could fend off a dog or two. But the dogs would probably get the chicks, I suspect. There are records in the early 19th century that dogs were used for hunting and they (Maori) also ate them. There were dog skeletons as well as moa."

There were also many remains of moa eggshell, which indicated the native people collected the large eggs. "They would not have been nesting there with a village right next door."

The moa bones told a story of waste. "They were not taken apart for every bit of meat. There were whole rib cages, heads and necks, with all the bones intact."

All they had removed were the meaty legs.

"There was one whole moa that Alistair excavated in the '60s or '70s and he maintained that it had been strangled. There's a photo of it, with its wind pipe popping out of its throat."

Destined to die

Looking back at the disappearance of moa, Cassels sighs: "If only."

But he puts it in perspective by looking at the moa's close cousin – the cassowary. The large flightless bird, which has a blue and red head, is found in Northern Australia and Papua New Guinea. "We know all about extinction and here they are nearly dying out. It's not a matter of will."

In the case of the moa, the Kaupokonui site clearly points to pre-historic overkill. But it's likely that over time, the moa would have gone the same way as the cassowary.

"The extinction of large flightless birds was clearly through the arrival of humans. I mean humans deliberately – you can't blame the tangata whenua (people of the land). Any human population would have had the same effect wherever they came from.

"It's just the fact that humans with dogs and rats, agriculture and fire, are not compatible with large, slow-moving ground-living birds."

The moa were destined to die out.