Monday, 5 December 2022

The Falkland Islands Wolf...or Fox?

 A Tad away from British foxes the Falklands canid has been one of the two symbol animals I use in my work -the other is the jackal. 

 Scientists solve the 320-year-old mystery of how the Falklands wolf ended up on the island: It skated across a frozen sea chasing a penguin

Experts were baffled by how the now extinct animal crossed the sea

Mystery was first recorded in 1690 - and raised again by Charles Darwin

Researchers analysed DNA from famously tame animal found by Darwin

 

DailyMail on Facebook

It is a mystery that has puzzled biologists - including Charles Darwin - for 320 years.

Biologists had been unable to work out how the Falklands wolf came to be the only land-based mammal on the isolated islands, which are 460km from the nearest land, Argentina.

Previous theories have suggested the wolf somehow rafted on ice or vegetation, crossed via a now-submerged land bridge or was even semi-domesticated and transported by early South American humans.



Illustration of 'Dusicyon australis', the Falklands wolf, from Zoology of the Voyage of H.M.S. Beagle. Researchers have now solved the mystery of how the wolf gor to the Flaklands - and say it skated across a frozen sea

THE FALKLANDS WOLF

The Falkland Islands wolf (Dusicyon australis), is also known as the warrah and occasionally as the Falkland Islands dog.

It was the only native land mammal of the Falkland Islands until it became extinct in 1876, making it the first known canid to have gone extinct in historical times.

The first recorded sighting was by Captain John Strong in 1690. He took one, but during the voyage back to Europe it became frightened by the firing of the ship's cannon and jumped overboard.

When Charles Darwin visited the islands in 1833 he found the species present on both West and East Falkland, and tame, but numbers were dwindling and he predicted that the animal would join the dodo among the extinct within 'a very few years.'

Islanders hunted it for its fur, and were also concerned it would attack sheep.

Now, University of Adelaide researchers have found the answer - and say the animals skated across a frozen sea, probably chasing a penguin or seal.



Researchers from the University’s Australian Centre for Ancient DNA (ACAD) extracted tiny pieces of tissue from the skull of a specimen collected personally by Darwin.

The 320-year-old mystery was first recorded by early British explorers in 1690 and raised again by Charles Darwin following his encounter with the famously tame species on his Beagle voyage in 1834.

The findings were published in Nature Communications today and concluded that, unlike earlier theories, the Falkland Islands wolf (Dusicyon australis) only became isolated about 16,000 years ago around the peak of the last glacial period.

'The eureka moment was finding evidence of submarine terraces off the coast of Argentina,' says study leader Professor Alan Cooper.

'They recorded the dramatically lowered sea levels during the Last Glacial Maximum (around 25-18,000 years ago).'

'At that time, there was a shallow and narrow (around 20km) strait between the islands and the mainland, allowing the Falkland Islands wolf to cross when the sea was frozen over, probably while pursuing marine prey like seals or penguins.

'Other small mammals like rats weren’t able to cross the ice.'

The team also used samples from a previously unknown specimen, which was recently re-discovered as a stuffed exhibit in the attic of Otago Museum in New Zealand.

The 'submarine terraces' that enabled the Falklands wolf to cross from Argentina during the Last Glacial Maximum (around 25-18,000 years ago). The image shows a shallow and narrow (around 20km) strait between the islands and the mainland

The yellow dots show the areas in Argentina the relatives of the Falklands Wolf were found, and the red marks its population on the island

'Previous studies used ancient DNA from museum specimens to suggest that the Falkland Islands wolf diverged genetically from its closest living relative, the South American maned wolf (Chrysocyon brachyurus) around seven million years ago,' said Associate Professor Jeremy Austin, Deputy Director of ACAD and co-lead author with Dr Julien Soubrier.

'As a result, they estimated that the wolf colonised the islands about 330,000 years ago by unknown means.

'Critically, however, these early studies hadn’t included an extinct relative from the mainland, the fox-like Dusicyon avus.

'We extracted ancient DNA from six specimens of D. avus collected across Argentina and Chile, and made comparisons with a wide group of extinct and living species in the same family.'

ACAD’s analyses showed that D. avus was the closest relative of the Falkland Islands wolf and they separated only 16,000 years ago – but the question of how the island colonisation came about remained.

The Falkland Islands wolf (Dusicyon australis), also known as the warrah and occasionally as the Falkland Islands dog.

It was the only native land mammal of the Falkland Islands until it became extinct in 1876, making it the first known canid to have become extinct in historical times

The Falklands wolf had baffled scientists, as they could not work out how it crossed from Argentina

The first recorded sighting was by Capt. John Strong in 1690.He took one, but during the voyage back to Europe it became frightened by the firing of the ship's cannon and jumped overboard.

When Charles Darwin visited the islands in 1833 he found the species present on both West and East Falkland, and tame, but number were dwindling and he predicted that the animal would join the dodo among the extinct within 'a very few years.'

Islanders hunted it for its fur, and were also concerned it would attack sheep.

 


No comments:

Post a Comment