Wednesday, September 28, 2016


Yesterday at Alturlie, both tree and house sparrows were feeding on the stubble field. When spooked, they flew to roadside weeds where they sometimes found it difficult to keep their balance in the very strong wind.


I've been revisiting the tern I saw at Tarbat Ness, as Arctic has been suggested. (I'm glad to see that I originally wrote "I think" it's a common tern; I wasn't 100% sure.) Here are a couple of juvenile terns seen at Poolewe earlier this month - I think I can safely say they're common terns.


There is a relic of the brown saddle mentioned in the BWP and of the brown loral spot mentioned to me; while the eye is clearly visible. But I know what the real sticking point with the Tarbat Ness tern was for me - the partially red bill. I kept reading that the juvenile Arctic has a dark bill, and illustrations I've looked at also showed a dark bill. Why would it be turning red?

Then I went back to my old field guide Birds of Europe by Lars Jonsson, who says "Juvenile has red bill base initially but bill becomes all-dark towards late summer". So I had it the wrong way round - the bill is on the way to losing its red base. Jonsson adds that the Arctic "has more dark around the eye than juvenile common" and that's borne out by my two pics; it was very difficult to bring out the eye of the Tarbat Ness bird in the photos. He also mentions the "prettier head" of the Arctic which can possibly be seen here; while the bill does appear shorter.


Finally, the legs aren't completely visible, but they give the impression of being the titchy legs of the Arctic, partly because of their angle. However, it is just an impression, and can't be seen as diagnostic.

I'm still not saying I'm 100% sure, but I think this could well be an immature Arctic tern after all. Anyway, it was an interesting problem and I feel I know a bit more about tern plumages than I did before.

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