Monday, September 13, 2010

Ogden - mystery tern?

Several more photo's taken this afternoon - in the pouring rain. We found these 2 terns around 1.30pm - they left around 6.0pm. (click on the photo's to enlarge)

Above - Mystery tern?
Above - Mystery tern?

Above - Common Tern


Common Tern - left




Common Tern - left



Common Tern - left






Common Tern - right

With apologies for the delay in getting these rather poor shots on but they do show some comparison between the two terns. The Common Tern was the obvious one with the longer orange/red legs and colour on the bill etc. The other one we struggled with all afternoon with the main debate being over whether it was Arctic Tern or Roseate Tern (?) Both terns flew around several times with calls being heard and the unidentified one was very pale underwing (with no trailing black bar on the wings), short black legs and black bill.
Any further thoughts on this bird?


1 comment:

Steve Cummings said...

Well done Dave.....photos as well...despite the crappy weather.
A bit tricky this. Short, dumpy legs and short bill suggest Arctic rather than Roseate but just discovered that juv Roseates can have short bills. Lack of black trailing edge suggests Roseate but the dumpy legs don't. I would expect a juv/1st summer Roseate to be as pale a grey as an adult. This bird does not seem pale enough to me but I might be wrong with this assumption. Age-wise, this bird has lost its scalloped young juv appearance, making it, perhaps, a late juv/1st-summer perhaps. The wing descriptions, particularly lack of black trailing edge, bother me though. They seem to point to Roseate. What is the possibility of a 1st summer hybrid Arctic x Roseate?