Tern influx in cold northerlies. Wintersett 04.05.12

Highlights  today were a male BLUE-HEADED WAGTAIL  on Anglers CP and an arrival of ARCTIC  TERNS from early to mid afternoon totalled 51 birds.  Interestingly a flock of 12 left north, calling, and then 10 minutes later a flock of 12 dropped in from a great height, calling.  These were obviously the same birds returning.  False departures happen regularly with terns, so overcounting could be a problem for the unaware. 
Other sightings were  Wintersett Res: Black Tern 2 still here, Common Tern 3.
Anglers CP: Pink-footed Goose 2, Wheatear 1 female, Yellow Wagtail 2.
Large numbers of hirundines and swifts were feeding over all water bodies.