A yellow-legged gull breeding nr Elegug Stacks

Did the 3 hr long whole colony counts at Stack Rocks (Elegug Stacks) yesterday. Numbers of fulmar and razorbill down - as noted at Stackpole. However, there is an interesting gull pair with 2 small chicks. One of the pair (prob the male) is a definite typical LBB. His partner though looks like a yellow-legged gull (certainly not LBB) with much paler grey wings (mid way between LBB and herring) and she has yellow legs.

However, as they are nesting in a small colony of mixed herring and LBBs, it seems just as likely that the LBB is mated with a hybrid herring x LBB. I wonder if this bird (if indeed it is a hybrid) may be a descendant of some of those manipulated experimental Skokholm LBB x herrings of some 25-30 years ago - are they still turning up and breeding anywhere else?

On the other hand, perhaps it is a real yellow-legged gull - it looks just like one of those Mediterranean birds and of course LBBs head down in that direction in winter! We may never know exactly what this one is. Its yellow legs may be a bit dirtier looking yellow than the LBB, but then again they may be a bit soiled.

It is nesting to the east of the main stacks. We have a short video-clip of the "yellow-legged" gull at the nest, Annie has not yet had time to look at this yet.