The National Park Service has built a five-mile-long fence around Mauna Loa on the Big Island in Hawaii. The purpose of the fence is to keep cats out, making it the longest cat-proof fence in the country. Isn't that nice, they're trying to save the poor kitties from death by volcano. Except, while it might keep cats away from flowing lava, that's not the purpose of the fence. It's to protect nesting birds from the cats.
Mauna Loa’s lava-covered slopes make for some seriously forbidding landscape, but that hasn’t deterred cats, which have adapted to the Hawaiian islands just fine since arriving on explorers’ ships. So fine, in fact, that the little invasive predators are now a mortal threat to the endangered Hawaiian petrel, a seabird that breeds on Mauna Loa. Several thousand of the birds live in Hawaii, but only about 75 breeding pairs are on the Big Island.
The fence, which took three years to erect, is six feet tall and has a special curved design at the top that is supposed to be cat-proof. I find it hard to believe that cats couldn't scale it if they had to, but I can well believe that it might be more difficult than a cat would consider worth the effort. -Thanks, John Farrier!
(Image credit: Scott Hall/National Fish and Wildlife Foundation)