A very large crop of a scene where and when a Great Black Backed Gull attacked, killed and ate part (insides)of a White Winged Scoter. The attack was quick and deliberate and it appeared that as soon as the Gull ( who had been shadowing a large flock of Goldeneye as they fished) saw the Scoter approaching from beyween 50 and 100 yards, it immediately took to the air and made a bee line for the scoter. The scoter dove several times but came up nearby and the gull appeared to know where that would be and many times struck the water so its possible the scoter did not dive deep and could be seen by the gull. Perhaps the White Winged Scoter was sick or injured (?) and the Gull perceived this however I have no way of knowing although for the 20 minutes I was watching the Scoter it never dove once to fish.......Another gull and possibly a juvenile Great Black Backed, came in shortly after but could not get too close to the scoter until the mature gull finished and departed. Shortly after that, the juvenile took to the air and circled the scoter while calling...obviously distressed. Above us were 3 Bald Eagles, one adult and two juvies higher up. I thought they were going to take the scoter but they moved on...the next image shows the adult. The juvenile returned to the carcass and we left.