It's raining birds in New Mexico. Dead birds. Deceased birds have been falling from the sky over several areas of the state in record numbers -- and wildlife experts say they have no idea why. "It's devastating," says ecologist Martha Desmond. "I don't think I've ever seen anything this horrible in my life -- you know, picking them up off the ground and seeing the extent of it and then looking at all these carcasses come in." Although several different species have fallen victim to the weird phenomenon, Desmond says all are insect-eaters. But so far, scientists have not been able to find a link between the birds' dietary habits and the deaths. "We honestly do not know," she says. "It could be that the weather moved it and pushed birds out early in Colorado, where it just snowed like crazy. Some of them might not have been ready to migrate and so they died in place."