Mice Make Trouble in the Farallones

The Farallon Islands have been crawling with house mice for years. They may have stowed away on boats and ridden out to the islands as early as the 1800s. Mice can be annoying or — if they’re your pets — cute, but in the Farallones they’re causing problems on a life-and-death scale.

“People on the island talk about how the ground moves because there’s so many mice,” explains Brad Keitt, the Director of Conservation for Island Conservation. The non-native mice attract burrowing owls, which would normally stop by the island for a meal, then head out. But the mouse bounty has caused them to extend their stay. And when the mouse population falls in the winter, the owls switch to eating birds, including the ashy storm-petrel, an endangered species that only nests on islands off the coast of California.

I wrote this for KQED’s news blog, News Fix, so read the rest there.

But before you go, let me take a moment to link to two excellent blogs by people who actually get to spend time on the islands (the Farallons are closed to the public): Los Farallones and Farallon Photo a Day.