Whilst walking along Humber bank on Sunday I observed a pair of birds gliding, I thought they were pale breasted buzzards at first as they were similar size. one if the birds then accelerated and went after a rather large gull The bird of prey flight was similar to that of a pigeon (but faster). The gull dived towards the humber with the bird of prey hot on its heals trying to catch it in flight. Gull landed in water and bird of prey returned to partner. Any ideas? Only ever see marsh harriers and buzzards along the bank.