Interesting but I don't know that this is as much learning or training as it is conditioning...?
And there is a difference. All animals can be conditioned to react to stimulus, but not many can be trained. For example one of my kingsnake's will come to me if I tap on the floor. Have I trained him, or does he associate the tapping with the three times I fed him on the floor instead of his tank and now he's been conditioned? I'm betting on conditioning and not training.