Explanation: The Romans were very fond of omens, and wise merchants could take advantage of that fact. When the Emperor Augustus returned from one of his harder-fought battles, he was met by a man who had a raven - which immediately greeted Augustus with 'Hail Caesar, victorious commander!' Augustus was tickled pink by this, and probably regarded it, as any upstanding Roman would, as a good omen to be greeted by such a trained bird (Romans LOVED taking any odd occurrence as an omen), and paid 5,000 denarii for the bird - the equivalent of over 20 years' pay for a common soldier! (one might compare it to $400,000 in the modern day)
Obviously this was a VERY CIVILIZED BIRD! AVE CAESAR!