The island fox (Urocyon littoralis) is an incredibly cute, miniature fox native to six of the eight Channel Islands just off the coast of Southern California. A close relative of the grey fox, the island fox is believed to have been brought to the islands more than a millennium ago by Native American settlers. Over the centuries, it became smaller and smaller due to Island Dwarfism and is now considered a separate species.
The island fox is a critically endangered species. There used to be thousands of these foxes all over the islands but beginning in the 1990s their numbers dramatically declined before anyone realized what was happening. Indeed, well into the 1990s, the US Navy was hunting and killing the foxes to protect a rare subspecies of the Loggerhead Shrike, which the foxes were eating. By 2000 there were only a tiny handful of foxes on each island (less than 20 per island).
It turned out that the cause of the dramatic decline was predation by golden eagles. The island fox is so tiny that it is easily preyed upon by the much larger golden eagle. Golden eagles had previously stayed away from the Channel Islands due to the presence of bald eagles (which did not prey on the foxes), but once the bald eagle was exterminated from the islands by DDT, the golden eagle began to move in, attracted by the feral pigs introduced by humans and by the foxes.
Since 2000, conservation efforts such as a captive breeding program have been successful in increasing island fox numbers to several hundred. However, the foxes will not be truly safe unless all the golden eagles are removed and the bald eagle is reintroduced to the islands. A project is underway to capture and remove the golden eagles to the mainland, but there is a lack of funds for the much more expensive undertaking of attempting to reintroduce the bald eagle, so the golden eagles may well return.