Cliffe Pools

A rather grey late afternoon at Cliffe,  properly with most birds too far away to photograph. I had a good look at the Great Black-backed Gulls for colour-rings, but had no luck reading the rings of the two (probably) Scandinavian birds - with orange rings on the left tibia - that were there.

Looking at the bills of the GBB Gulls, few seemed entirely adult, and although this one was close, the dark marking on the bill might indicate either a 4th winter or young adult bird.  A Juvenile GBB and juvenile Herring Gull behind and to the right.

This is probably a first winter bird, with a completely black bill, and now a paler head than a juvenile:

This is quite a nice view of what is probably a third winter bird with the tip of the bill turning yellow but the rest remaining black, and what looks like a mix of grey and black on the back:

This group below I think  indicates the variation in apparent size of the Great Black-backed Gull, with the younger male on the right (bill completely black, grey markings on the back) being substantially bigger than what are probably first a 4th winter female (slight black markings on the bill) and then an adult female on the left - and then I wasn't not sure of the rearmost bird.

This youngster is showing the classic angled forehead, flat crown and rather mean eye, together with the parallel-sided large bill with a bulbous tip.