They are only found on the coast, usually on estuaries with saltmarshes. I clearly remember that I first saw them in Essex, at Goldhanger on the Blackwater estuary. Donna Nook is at the southern end of the Humber estuary.
Not long after my marriage broke up and I returned to Essex to lick my wounds I walked down Southend Pier. As I got to the bottom a flock flew past, presumably on their way to Leigh Marshes. Somehow it made feel illogically better.
