Why, oh why, oh why, do people do gull roosts? Staring through the murk at little white blobs bobbing up and down in the water, looking for a blob with a bit more white somewhere, or a bit of a darker grey bit or whatever....but it is darn addictive and one of the most exciting of winter birding pastimes...if you do Grafham as a patch that is. On Sunday arvo, the light was nice and some of the gulls were actually at a reasonable distance for once. Shortly after starting the larid scrutiny, a fine adult Caspian Gull with typical weedy reedy beak and bullet hole eye pitched in in a near group and I managed a couple of shots. I had to head for York, so I left fellow gull-nutter, Mark, to continue the grilling.