When Charles Darwin stopped briefly at the Falkland Islands on the famous voyage of the Beagle, he ran into one of the great mysteries in animal evolution. The islands had just one native terrestrial mammal, which he confusingly described as a “wolf-like fox”. It wasn’t clear what the species was descended from, or how it had ended up in such a remote place, hundreds of kilometres from the nearest mainland.
The Falkland Islands wolf, known also as the warrah or Dusicyon australis, was hunted to extinction in the latter half of the 19th century. As such it was little studied. Darwin’s visit, in the species’ final decades, remains one of the only scientific observations of this poor animal.
Scientists long thought that the extinct Falklands wolf was, as its name suggests, similar to a wolf. However, new research by colleagues and me published in the journal Mammal Review reveals that, in terms of skull shape and feeding habits, this mysterious “wolf” was more like a jackal.
Where it came from
The Falklands wolf had previously been linked to wolves, coyotes and domestic dogs, and scientists even named it Canis antarticus. It wasn’t until 2009 that DNA analysis was used to prove its closest living relative is the maned wolf of South America, which is actually neither a wolf nor a fox. Nevertheless, this species of wild canid (the wider dog family) is characterised by unusually tall limbs, which make it very different from the rather sturdy Falklands wolf.
JG Keulemans / BHL, CC BY-NC-SA
So where did the Falklands wolf come from? By looking through the South American fossil record, scientists identified its direct ancestor as an extinct fox known as Dusicyon avus which was once found as far south as Patagonia. A 2013 study found Falklands wolf DNA split from its mainland ancestors about 16,000 years ago – during the last ice age.
At that point, when sea levels were much lower, Patagonia was only separated from the Falklands by a small passage of shallow sea which would have frozen over at times. This meant Dusicyon avus probably walked across an ice bridge to the Falklands, before evolving in complete isolation into the warrah.
From wolf to jackal
Mystery solved. So we now know where the warrah came from, but what was it actually like? I wanted to figure out its ecology, and that meant looking at its bones and comparing them to other canids and what we know about their behaviour.
To do this, I worked with a team of LJMU colleagues, a paleontologist from Argentina, and curators at the Natural History Museum (NHM) in London. We dug through the cupboards at the NHM and World Museum Liverpool to build a database of more than 120 digital images of representative skulls of living wild canid species, including rare specimens of Falklands wolf and its ancestor Dusicyon avus.