I have to thank Lizard Naturally for both the final content of this Blog update, and for pointing out an error in my gull identification today, which meant that I originally assumed I had one gull species, when I actually had two!
Returning to Southsea seafront this morning, I headed west past South Parade Pier and spotted a white-winged gull on the foreshore amongst other gulls, I assumed it was the same 1w Iceland Gull (Larus glaucoides) - previously reported 2nd - 10th Jan 2016 in the same area (and whom I had photographed on the 8th). I grabbed a few hasty distant record shots, before the gulls flushed and I lost sight of the bird as it flew west. I then walked to Southsea Castle, where almost immediately a 1w winter Iceland Gull flew over my head.
Returning home, I quickly posted two of the photos on WhatsApp. Later on I editted the close up picture of the Iceland gull, and posted it widely. I put the following three pictures on my Blog, and wittered on about the Iceland gull! Hurrah!
This evening I received feedback on WhatsApp, identifying the first bird as a Glaucous gull (Larus hyperboreus)!; it's large size, long neck and heavy bill, being more obvious, when the original photos are blown up and cropped. The message also confirmed my correct identification of the 1w Iceland gull, seen close in and overhead.
Only somewhat embarrassed about the original misidentification, made in haste and then skewed by the immediate finding of the second bird. I will learn by the mistake!