Crows, Toads, and Liver

Where does BrianF find this stuff? Well, we know, because he provides the links.
I note that much of it has come from the ABC [Australian Broadcasting Corporation]

Hungry crows behind toad explosions

Toads have been exploding by the hundred in Germany because they are being attacked by crows, a veterinary surgeon has revealed.

Animal welfare workers and veterinarians had reported that as many as 1,000 toads had swelled to bursting point and exploded in recent days, propelling their entrails up to a metre into the air.

Veterinary surgeon Frank Mutschmann, who has examined the remains of the toads, says they have been pierced with a single peck by crows trying to eat their livers. This in turn causes the toads to explode.

"The toads swell up as a form of self-defence," Dr Mutschmann said.

"But when their livers are taken away and their stomachs are punctured, their blood vessels explode, their lungs collapse and the other organs come out."

..."Crows are intelligent animals. They learn very quickly how to eat the toads' livers," he said.

This story puzzles me. If crows are so smart, have they been doing this for centuries? If so, why is it news now? And if not, why did they learn how to do it only recently and not earlier?