My bet is on Ravens, who live a long time, and the ancients among them get a white flight feathers in the wings which I have seen once, up close in a nieghbors yard who was closer with the critters than humans. My fealing of ravens inteligence is based on there complex behaviors and one particular individual,who is bat shit insane, and makes the wildest strangest sounds and calls that are impossible to ignore for hours, but survives year to year, ie:dumb things never go crazy and or never survive there disfunctions. ravens also fly upside down regularly, and have been filmed pranking wolves by pulling there tails, and there is strong evidence for ravens working as spotters and leading wolves to easy/injured prey that the ravens get to clean up after the kill