Birds May Be Behind Exploding German Toads

Is this the first time crows have ever done this kind of thing? Because, while I feel better about it not being some kind of freaky contagious disease, I'm still a little disconcerted by crows suddenly (and selectively) plucking the livers out of specific frogs in a manner which seems to have taken biologists by surprise. Maybe we should be looking into the chemicals found in these livers and the diseases in these crows, as animals do self-medicate.