The Falklands Island Wolf, or warrah, was the only native land mammal endemic to the Falklands. They were already in decline when Charles Darwin visited on the Beagle in 1834, and by 1876 they were all gone. What did for them was a combination of the fur trade and the introduction of sheep farming:
The extermination of the warrah from East Falkland may date from the 1839 expedition of John Jacob Astor (a fur dealer in New York who sent a team to collect warrah skins). By 1865 they were no longer found in the eastern part of East Falklands. As it was reported that the animals were known to kill sheep, a poisoning campaign was undertaken and many were destroyed. By the year 1870 they were reported almost exterminated with the last one said to have been killed in 1876 at Shallow Bay, West Falkland Islands.
The task of killing them was made easier by the fact that the unfortunate beasts had no fear of humans. As other extinct species like the dodo or the giant New Zealand moas could testify, that particular kind of naivete generally tends to be fatal. They could be lured with a chunk of meat held in one hand, while the other hand held a knife or stone.
The mystery here, of course, is: how on earth did their ancestors originally arrive on the Falklands? They were certainly there when Europeans first landed. Captain John Strong, in 1690, took one on board to bring back to England, but the animal was frightened by the ship's cannon during a skirmish with the French, and jumped overboard.
There were plenty of them, too:
When Commodore John Byron arrived in the Falklands in 1765 he sent men to West Falkland. When they tried to land they were driven back into the boat “by four creatures of great fierceness resembling wolves”.
The next day, when Byron went ashore a warrah came running towards him. He shot it and his crew killed five more that day.
“They were always called wolves by the ship’s company, but except for their size, and the shape of the tail, I think they bore a greater resemblance to a fox. They are as big as a mastiff and their fangs are remarkably long and sharp.”
He described how his men tried to drive away the warrahs, which they believed to be aggressive:
“To get rid of these creatures our people set fire to the grass, so that the country was in a blaze as far as they eye could reach, for several days, and we could see them running in great numbers to see other quarters.”
The islands have never been connected to the mainland, and there's no equivalent example of canids, or any mammals of similar size, ever making such a major - 300 mile - trip across open ocean. One obvious answer might be that they'd been brought over from the mainland by Patagonian Indians, but there's no evidence that Indians ever visited the Falklands. Gavin Menzies, in his eccentric book 1421, suggested that the Chinese had dropped some dogs off in the course of their world tour.
Then in 2009 Graham Slater and colleagues at the University of California did some DNA analysis (pdf) on some of the few remaining museum specimens. They found that the animals last shared a common ancestor some 330,000 years ago, which effectively ruled out any human involvement in the development and isolation of the species. Further, surprisingly, they found that the nearest relative to the warrah was the South American Maned Wolf, and that the two lines had split some 6 million years ago. As canids only arrived in South America some 3 million years ago with the formation of the Isthmus of Panama, their last common ancestor would have lived in North America.
There may, of course, have been other closer relatives in South America which have since died out. Slater suggested Dusicyon avus, known from fossils from Patagonia as recent as 6,000 to 8,000 years ago, as a possibility.
So how did they get across to the Falklands? They clearly didn't swim. It's just about possible that a pack was caught on one of Patagonia's glaciers as it calved a massive iceberg, and they drifted out to sea. The most likely scenario though is that they made it over during one of the recent (340,000 years ago, 150,000 years ago or about 25,000 years ago) ice ages, when there may have been a solid ice sheet across from the South American continent.
That would have been some journey. It's a pity there was no David Attenborough around at the time to comment breathlessly on this remarkable story as the camera tracked their advance across the frozen wastes: surely, as he would say, one of the most amazing tales of evolutionary survival against the odds on the planet.
Until, that is, they met us.
More on Darwin and the 'Falklands fox' on my Friends of Charles Darwin blog:
http://blog.friendsofdarwin.com/2010/06/20100618/
(Incidentally, your comment fields do not have labels.)
Posted by: Richard Carter, FCD | November 14, 2011 at 12:28 PM
Thanks for the link.
(Not sure what you mean about the labels.)
Posted by: Mick H | November 14, 2011 at 02:19 PM