Thanks to everyone who replied with ideas about my mystery tern. Several
people suggested a Sandwich Tern but I have my doubts. The subject bird
seemed slightly smaller than the Common Terns while a Sandwich would be
larger. We did see a Sandwich Tern come in for comparison and the
subject bird was noticeably smaller. Unfortunately I didn't get a
picture of the two together. Several people also noticed the pale,
yellowish tip to the bill. Dave Youker pointed out that non-breeding
Common Terns can have a pale tip to the bill. This can be seen in the
non-breeding adult image on All About Birds.
And after a few questions I looked more carefully at the "feeding"
pictures and realized that I don't actually see anything in either
bird's bill before or after the encounter. The interaction wasn't
aggressive but perhaps it wasn't feeding either.
So I will leave it as a probable Common Tern but with some unusual
aspects to it. There was a suggestion from Gerry Hawkins that it might
be a hybrid. Interesting possibly to consider.
All in all, it has been a fun exercise and thanks again to everyone who
replied.
cheers,
Bryan
