The Island Fox Nearly Vanished From the Channel Islands. Then It Made a Record Comeback.
The house cat–sized island fox lives only on California’s Channel Islands. In the late 1990s it nearly disappeared. Here’s how it came back faster than almost any endangered mammal in U.S. history.
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If you camp on the Channel Islands, there’s a good chance a small gray fox will wander into your campsite looking for a snack. It’s about the size of a house cat, it’s not particularly afraid of you, and it lives nowhere else on Earth. That’s the island fox (Urocyon littoralis), and 20 years ago it nearly disappeared.
Island foxes live on six of the eight Channel Islands off Southern California. Each island’s population has been isolated long enough to become its own subspecies, a textbook case of what biologists call allopatric speciation: separate a group of animals, give it enough time, and it starts turning into something new.
They’re also small, much smaller than their ancestor on the mainland, the gray fox. That’s insular dwarfism, something that happens a lot on islands, where food is limited. The Channel Islands are full of examples of island biogeography in action. The best known is the pygmy mammoth (Mammuthus exilis), whose remains have been found on Santa Rosa Island. It stood only about as tall as a person.
Skeleton of the Pygmy Mammoth at the Santa Barbara Museum of Natural History
Island foxes are curious and smart. They’re mostly nocturnal, but they come out in daylight too, especially where there are campers and food. On Anacapa, Santa Rosa and Santa Cruz, the most visited islands, they patrol campgrounds for scraps and will walk right up to people, which isn’t great for them. I’ve camped out there with them, and the photos in this story are from those trips. They eat almost anything, including fruit, insects, mice and birds, shifting their diet with the seasons.
Foxes pair up for the breeding season, which runs from January to March. About 50 days after mating, the female has a litter of two to four pups. The young are on their own within the year and can breed at about 10 months old. In the wild, an island fox usually lives 4 to 6 years.
Island Fox on the Channel Islands (Photo: Erik Olsen)
In the late 1990s, island foxes crashed. Golden eagles had moved onto the islands and started picking them off, and disease swept through the population on Catalina. By 2004, some islands had fewer than 100 foxes left, and four of the subspecies were listed as endangered.
Island Fox looking for food scraps. (Photo: Erik Olsen)
What happened next is one of the great comeback stories in American conservation. The National Park Service, The Nature Conservancy and others bred foxes in captivity, vaccinated them against disease and moved the golden eagles off the islands. They also brought back bald eagles, which eat fish rather than foxes and keep golden eagles away. It worked fast. In 2016, three of the subspecies were taken off the endangered list and Catalina’s was downgraded to threatened, one of the fastest recoveries of any endangered mammal in U.S. history.
So if a little fox shows up at your picnic table on Santa Cruz Island, enjoy it, but don’t feed it. It took a lot of work to get it there.
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