I also had just rare opportunities to shoot these terns, and they tended to not come too close to my shooting position, necessitating some cropping here as well. But I do like the contrast of the black and white bird against the gently colored backgrounds. Canon 100-400 with Canon 1.4x II Teleconverter at 435 mm, ISO 200, f/8, 1/640 second, Wimberley Sidekick/Arca Swiss Ballhead/Gitzo Tripod (manual mode, manual focus).