If you hear croaking coming from your Christmas tree, turn on the lights and prepare the Orajel. As cute as he may be, and as sweet his song, the camouflaged frog ornamenting your branch will need to die before he hops a ride up the chimney with Santa. At least two Pacific chorus frogs (also know as Pacific tree frogs) have made their way to Anchorage with a shipment of out-of-state Christmas trees. This common species, not native to Alaska, "could be carrying some ugly viruses and funguses, including chytrid fungus that is devastating amphibians around the world," reports the AP. Amphibians may be the planet's canary in the coal mine, and face what many experts consider the most significant mass extinction since the dinosaurs. "When frogs and other amphibians, which have existed for hundreds of millions of years, start to vanish, it is a sign that our natural world is in a state of peril," wrote Animal Planet's Jeff Corwin in a recent Los Angeles Times editorial. Researchers have...