Firstly, thank you so much for your answer to my last question, which I have only just seen. I stupidly assumed I'd somehow get an email to tell me there was a reply, hence the long gap before my thanks. Apologies.
Today has been very hot here in the east of the UK and I have seen huge numbers of seagulls flying very high, so they were merely dots in the sky. They were not flying on thermals, the flight was random. There were huge numbers of them and they'd be visible, then move off somewhere and then move back. Any idea what they were doing? I have seen crows/rooks exhibiting similar behaviour.
I am incredibly grateful for you giving your time to answer my questions; thank you sooo much.