Why did the Maori dog kuri die out? Scientists looks for clues in old hair and bones

Friday, 17 July 2015

You are what you eat, as the saying goes. It's more accurate than you might imagine - a single hair can tell tales about the food that helped it grow.

So scientists hope hairs shed from dog skin cloaks could help unlock the mystery of why the once-beloved Maori dog, or kuri, disappeared almost without a trace.

The stout, stubby-legged kuri journeyed to New Zealand on the waka of Maori settlers. It served as hunter, sharp nose, provider of warm clothing and as a walking fridge.

But it was also a valued companion, as Captain Cook's naturalist George Forster reported on seeing kuri in waka in Queen Charlotte Sound in the 1770s: 'A good many dogs were observed in their canoes, which they seemed very fond of, and kept tied with a string round their middle; they were of a rough long-haired sort with pricked ears, and much resembled the common shepherd's cur.'

The crew bought some of the kuri. On being separated from their owners, the older dogs became sulky and refused to eat.

Kuri disappeared some time in the 19th century, after the arrival of Europeans. Landcare Research ecologist Priscilla Wehi wanted to know, how could something so valued slip slowly out of existence, seemingly without explanation?

'We don't know why and that's one of the really bizarre things . . . It's a great big empty hole where there's not enough information.'

While it's likely that kuri interbred with European dogs and gradually died out, there's no clear evidence of that, Wehi says. There's also no documentation of any rampant disease.

The kuri's only remnants are its signature in place names around the country, its bones dug out of middens, a stunted stuffed specimen in Te Papa and the soft white hairs used to create kahu kuri, the most prized of Maori cloaks.

It is those hairs that Wehi hopes will provide the clue to what kuri ate and whether a change in diet between pre-European and post-European times could signal a shift in the relationship between man and dog, thus solving the mystery of why the Maori dog died out.

She has used her three-year, $300,000 Marsden Grant to collaborate with GNS Science senior scientist Karyne Rogers. A year into the project exciting patterns are already emerging.

Rogers has analysed hairs naturally shed from 20 cloaks - most now in the care of Te Papa - to find out what their owners ate.

Each hair is dissected into small pieces and its nitrogen and carbon isotope signatures are analysed in a mass spectrometer. While the process can't show that dog X had a daily diet of five rats, six kereru and a handful of grains, it can reveal how much protein or meat the dog ate.

The nitrogen isotope signature increases as you go up the food chain, from about 5-6 per mil (parts per thousand) for a vegan to 10 or 11 per mil for a secondary carnivore such as a human or dog. Because the ocean has longer food chains, a top end predator such as a shark could have a nitrogen isotope signature as high as 17 or 18 per mil.

Add in the carbon isotopes, which distinguish between plants or birds and marine food such as shellfish or fish, and the scientists can also determine whether the dogs lived on the coast or inland.

But here's the tricky bit. The team needed to know what the chemical signature of hair from dogs fed different types of food would look like. So they roped in some citizen scientists.

In the sample room at Rogers's lab north of Wellington, coils of hair are packed into plastic capsules alongside the envelopes containing the precious kuri hair fragments.

Wehi and Rogers could not believe their luck when they discovered vegan and vegetarian pet owners who also had vegan and vegetarian dogs.

'So we can see what these dogs are eating and how they match up with the 1800s hair from kuri cloaks,' Rogers says.

Early data shows some kuri ate as well as modern carnivorous dogs while others ate less protein than a modern vegan dog, suggesting they might have had to scavenge for food.

The isotope results also show some kuri lived inland while others lived in coastal areas, dining on a rich diet of seabirds and fish. The coastal dogs were obviously fed from their owners' tables, indicating that they were well cared for.

The second phase, which is about to begin, is to analyse kuri bones salvaged by Otago University archaeologist Ian Barber from two 14th and 15th century South Island middens, or rubbish heaps. The team can then test whether the kuri diet changed significantly between early days of Maori settlement and the period of tremendous social upheaval that accompanied the arrival of European settlers.

The hair and bone analysis can't reveal everything about how and why the relationship between Maori and their dogs changed. That is why Wehi is also researching whakatauki, or ancestral sayings, and newspaper reports from the early days of European settlement.

'That's been fascinating in itself,' Wehi says. 'We have early farmers talking about what a menace the Maori dogs are as they run free. There's really strong attitudes associated with opening up the land for farming. They really want to get rid of all the dogs.'

A letter to the Wellington Independent in 1848 talks of Maori dogs 'who play the devil with the settler's flocks'. Another complains of the 'probability of being devoured by dogs' when passing Wellington's Pipitea and Te Aro pas.

One letter, which talks of 31 of Mr Crawford's ewes being attacked and killed by native dogs says 'there are always a number at each pa belonging to no particular owner'.

However, an 1845 column in the The Nelson Examiner mocking the proposed Dog Nuisance Ordnance suggests authorities favoured kuri over European dogs. 'The bark of a Maori dog will go much further with our Government than the remonstrance of an English man.'

Wehi hopes oral history tradition will also help explain just how domesticated kuri really were.

'When Cook made his first voyage to New Zealand he saw dogs on the waka with Maori so they were quite well looked after and you could see there was a close relationship. We know that other dogs were looked after within settlements and were very well fed - they might be dogs that belonged to the chief. But we don't know whether that was always the case or whether they were special exceptions.'

White kuri hairs appear to have been favoured for making cloaks. By testing both black and white hairs, the team also hopes to discover whether white dogs were therefore the king of dogs and were better fed.

 And all from single hairs shed from 250-year-old cloaks.