Jon shifted the bucket to his right hand and thrust his left down into the bloody bits. The ravens began to scream noisily and fly at the bars, beating at the metal with night-black wings. The meat had been chopped into pieces no larger than a finger joint. He lifted his fist and tossed the raw red morsels into the cage, and the squawking and squabbling grew hotter. Feathers flew as two of the larger birds fought over a choice piece. Quickly Jon grabbed a second handful and threw it in after the first. "Lord Mormont's raven likes fruit and corn."
He is a rare bird, the maester said. "Most ravens will eat grain, but they prefer flesh. It makes them strong, and I fear they relish the taste of blood. In that they are like men... and like men, not all ravens are alike."
Jon had nothing to say to that. He threw meat, wondering why he'd been summoned. No doubt the old man would tell him, in his own good time. Maester Aemon was not a man to be hurried.
Doves and pigeons can also be trained to carry messages, the maester went on, "though the raven is a stronger flyer, larger, bolder, far more clever, better able to defend itself against hawks... yet ravens are black, and they eat the dead, so some godly men abhor them.