Scientists prove that a mysterious black mega-swan mentioned in ancient legends lived in New Zealand until the 13th century

  • Pouwa black swan has existed in legends from New Zealand's Moriori people
  • Scientists compared fossils found in New Zealand with modern black swans
  • Their analysis shows that the fossils belonged to a unique species
  • The swans were 20 to 30 per cent heavier than modern Australian black swans, and would have weighed up to 10 kilograms 

Stories of black mega-swans in New Zealand have long existed in legends from Moriori people.

Up until now, no direct evidence of these mysterious creatures has ever been found. 

Some researchers suggested the legends may refer to the Australian black swan, which can fly over the Tasman Sea.

Now, a new study says it has proven, for the first time, that the elusive black mega-swan of New Zealand existed, and was its own, unique species.

Researchers say the semi-flightless black swan died out in New Zealand after humans first arrived from Polynesia in the 13th Century.

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A new study says it has proven, for the first time, that the elusive black mega-swan of New Zealand existed, and was its own, unique species. Pictured is a mounted skeleton of the creature

A new study says it has proven, for the first time, that the elusive black mega-swan of New Zealand existed, and was its own, unique species. Pictured is a mounted skeleton of the creature

NEW ZEALAND'S BLACK SWAN 

Australian black swans first arrived in New Zealand about two million years ago, during the Pleistocene Ice Age.

There, they rapidly evolved into Pouwa, weighing up to four kilograms more than Australian swans, developing elongated legs and becoming more terrestrial in habitat.

Dr Rawlence said: 'One of the interesting findings comes from the highly elongated leg bones, which shows they were already on the path towards flightlessness.

'Birds seem to get these elongated legs in island ecosystems where there are no mammalian predators and the top predators are birds, like the extinct Haast's Eagle and Eyles' Harrier.'

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The discovery was made after researchers at the University of Otago compared DNA from 47 modern Australian black swans and 39 ancient swan fossils found at archaeological sites around New Zealand.

Analysis of ancient DNA and bone dimensions shows Pouwa was between 20 to 30 per cent heavier than modern Australian black swans, and weighed around 10 kilograms

The researchers also found that Pouwa were on the way to becoming flightless when they became extinct. 

Dr Nic Rawlence, who led the study, said the findings are one of a 'growing number of examples of extinction and colonisation since the arrival of people in New Zealand.'

Australian black swans first arrived in New Zealand about two million years ago, during the Pleistocene Ice Age.

There, they rapidly evolved into Pouwa, weighing up to four kilograms more than Australian swans, developing elongated legs and becoming more terrestrial in habitat.

Dr Rawlence said: 'One of the interesting findings comes from the highly elongated leg bones, which shows they were already on the path towards flightlessness.

'Birds seem to get these elongated legs in island ecosystems where there are no mammalian predators and the top predators are birds, like the extinct Haast's Eagle and Eyles' Harrier.'

Until the mid-1990s, scientists believed that black swans in New Zealand when Polynesians arrived in the 13th century were the same as the swans in Australia today.

Analysis of ancient DNA and bone dimensions shows Pouwa was between 20 to 30 per cent heavier than modern Australian black swans, and weighed around 10 kilograms

Analysis of ancient DNA and bone dimensions shows Pouwa was between 20 to 30 per cent heavier than modern Australian black swans, and weighed around 10 kilograms

But when Europeans arrived in New Zealand in the late 18th century, there were no black swans at all.

Instead, the Europeans introduced Australian black swans to New Zealand in the 1860s.

Dr Rawlence said: 'Within three or four years their population had grown and spread to the point that we suspect they must have been self-introduced as well.

While a black swan species from Australia still exists today (pictured), a team of researchers led by the University of Otago has proved that the Pouwa was a unique species 

While a black swan species from Australia still exists today (pictured), a team of researchers led by the University of Otago has proved that the Pouwa was a unique species 

UNIQUE OPPORTUNITIES IN NEW ZEALAND 

The researchers believe that New Zealand has a huge natural advantage in these kinds of studies.

Dr Rawlence said: 'As one of the last major land masses to be settled by humans, New Zealand has an excellent recent and well-preserved archaeological record, including for swans. We can separate out climate-change effects from change driven by humans.

'This research shows how the arrival of humans can rapidly change island ecosystems.

'It may also raise new questions when it comes to ecological restoration and, perhaps, even de-extinction.

'Our research shows that, in some cases, you cannot assume that closely related species are surrogates.

The Pouwa's ecology might have been fundamentally different from that of the Australian black swan.' 

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'They'd probably been rocking up in New Zealand the whole time, but never been able to establish here until after the arrival of Europeans.'

The researchers looked at 39 ancient fossil samples found in New Zealand, and compared them with DNA from 47 modern Australian swans.

Dr Rawlence said: 'We assessed museum and archaeological collections, and extracted ancient DNA in our laboratory, looked at bumps on bones and took bone measurements to characterise their shape.

'We have shown now that the new Australian arrivals are not exactly replacements of the Pouwa.

'So this raises the question - what does it truly mean to be native? Is the Australian black swan a pest or something to be protected?'

The researchers believe that New Zealand has a huge natural advantage in these kinds of studies.

Dr Rawlence said: 'As one of the last major land masses to be settled by humans, New Zealand has an excellent recent and well-preserved archaeological record, including for swans. We can separate out climate-change effects from change driven by humans.

'This research shows how the arrival of humans can rapidly change island ecosystems.

The researchers believe that New Zealand has a huge natural advantage in these kinds of studies, as it is one of the last major land masses to be settled by humans

The researchers believe that New Zealand has a huge natural advantage in these kinds of studies, as it is one of the last major land masses to be settled by humans

'It may also raise new questions when it comes to ecological restoration and, perhaps, even de-extinction.

'Our research shows that, in some cases, you cannot assume that closely related species are surrogates.

'The Pouwa's ecology might have been fundamentally different from that of the Australian black swan.'