The Falkland Islands wolf, or warrah (Dusicyon australis), was the only native land mammal of the Falkland Islands. This endemic canid became extinct in 1876.

It was once believed that the most closely related genus was South American fox (Lycalopex), including the culpeo, a fox-like mammal which was introduced to the Falkland Islands in modern times. A 2009 cladistic analysis of DNA identified the Falkland Islands wolf's closest living relative as the maned wolf (Chrysocyon brachyurus), an unusually long-legged, fox-like South American canid, from which it separated about 6.7 million years ago. However, the Falkland Islands wolf diverged from its mainland ancestor Dusicyon avus only around 16,000 years ago. Dusicyon avus persisted on the South American mainland until around 400 years ago.

The Falkland Islands wolf existed on both West and East Falkland. Charles Darwin was uncertain if they were differentiated varieties or subspecies. Its fur had a tawny colour and the tip of the tail was white. Its diet is unknown, but without native rodents on the Falklands, the Falkland Islands wolf likely subsisted on seashore scavenging, ground-nesting birds, like geese and penguins, as well as seal pups and insects. It has been suggested they may have lived in burrows.

Recent studies suggest it may have either naturally colonized the Falkland Islands or originate from domesticated Dusicyon avus brought to the islands by people before European settlers arrived.

History

thumb|left|Skull

The first recorded sighting of a Falkland Islands wolf was by Captain John Strong in 1690. Captain Strong took one on his ship. However, during the voyage back to Europe, it became frightened by the firing of the ship's cannon and jumped overboard. Louis Antoine de Bougainville, who established the first settlement in the Falkland Islands termed it a loup-renard ("wolf-fox").

thumb|The Falkland Island wolf was hunted for its fur.

When Charles Darwin visited the islands in 1833 he found the species present in both West and East Falkland and tame. However, at the time of his visit, the Falkland Islands wolf was already very rare on East Falkland, and its numbers were declining rapidly on West Falkland. By 1865, the Falkland Islands wolf was no longer found on the eastern part of East Falkland. Darwin predicted it would be extinct like the dodo within "a very few years."

The Falkland Islands wolf was hunted for its valuable fur and settlers who regarded the wolf as a threat to their sheep poisoned it. However, the belief that Falkland Islands wolf was a threat to sheep was probably due to the sheep mistaking the Falkland Islands wolves for dogs (especially at night), and, in terror, the sheep ran into bogs and swamps, where they became lost. There were no forests for the animal to hide in, and it had no fear of humans; it was possible to lure the animal with a chunk of meat held in one hand, and kill it with a knife held in the other.

A live wolf was taken to London Zoo, England in 1868. Another "Antarctic wolf" arrived in 1870. Neither animal survived long. Only a dozen or so museum specimens exist today.

The word "would" was added after this passage was first written, suggesting a cautious qualification from his initial bold statement. He later wrote that such facts "seemed to me to throw some light on the origin of species".

A DNA analysis suggest that the closest living relative of the Falkland Islands wolf is the South American maned wolf.

In terms of skull shape and feeding habits, the animal was an opportunistic predator, more like a jackal.

Biogeographical isolation on the Falklands

The route by which the Falkland Islands wolf was established in the islands was unknown for a long time, as the islands have never been connected to the mainland and there are no other native land mammals. No other oceanic island as remote as the Falklands has a native canid; the island fox of California in the US and Darwin's fox of Chile both inhabit islands much closer to a continent.

Berta and other authors suggest that it was unlikely that the wolf's ancestors could have survived the last Ice Age on the Falklands and they must therefore have arrived later, within the last ten thousand years, crossing a wide expanse of the South Atlantic. Its close relative, Dusicyon avus, did survive in South America until a few thousand years ago, but swimming such a distance or even drifting on a floating log would appear effectively impossible for the wolf. A study by a University of Maine team in 2021 reports evidence of potential visitation to the islands by indigenous South Americans before the Age of Discovery. The authors speculated that the ancestors of the wolf could have been domesticated and brought with the visitors.

The oldest known remains of Falklands Islands wolves date to approximately 3396–3752 years Before Present, found at Spring Point Farm in West Falkland, the only place in the Falkland Islands where subfossil bones of the wolf have been found. The scarcity of remains is likely due to the acidic peaty soil of most of the Falklands, which rapidly degrades bones. giving some idea of the genetic diversity of the founding population.

Ice Age land bridge

An Ice Age land bridge or ice connection between the Falkland Islands and South America, enabling the species' ancestors to traverse the gap, has long been suggested. There was never a true land bridge between the islands and South America, but submarine terraces have been found on the Argentine coastal shelf, formed by low sea-stands during the last glacial phase.