Why do some California coyotes suddenly have blue eyes?

This blue-eyed coyote, spotted in April by wildlife guide Daniel Dietrich and photographed by National Geographic's Callie Broaddus, was the first among at least five confirmed mutants to be identified in the Bay Area. Credit: Callie Broaddus.

Most Angelenos are familiar with what coyotes look like: large ears, black noses, greyish and rust-colored fur, and yellow eyes. But five coyotes have recently been spotted with blue eyes in California.