Escaped from work for a quick look at the Gann at midday (just after high tide), it was hard going in the wind which topped over 65 mp/h at St Ann's Head at the same time!
Recorded 3 species of tern on the beach: 2 Sandwich (adult & juv), 1 Common (juv - which was metal ringed but I couldn't read it, of course!) & 2 Arctics (both juvs). I can't ever recall recording 3 species of tern at the Gann at the same time. They were mainly hunkering down in the wind, occasionally flying about, with some stealth allowing a close approach. It was hard to keep the binoculars steady in the wind, so I fired off some photos for later analysis. I freely admit that I am not that familiar with terns in comparison to other groups, so the photos allowed some critical analysis at home afterwards and to firm up the identification of the Common & Arctics, which can be tricky at the best of times. All very instructive! Photos below, apologies for the large number...
