birding-aus

Help with Bird ID please

To: "Nikolas Haass" <>, "Peter Madvig" <>, "M & P Potter" <>, <>
Subject: Help with Bird ID please
From: "Mike Carter" <>
Date: Sun, 27 Nov 2011 23:08:46 +1100
I agree with Nikolas that this is a pale morph Jaeger in very worn plumage, definitely not a Pomarine Jaeger, most probably an Arctic Jaeger rather than a Long-tailed (because of the pale blaze - but there is only a small amount of white at the base of the primaries which leaves me a little unsure). However, I have more of a problem accepting that it is an adult as the white spots on the mantle look to be remnants of juvenile barring the presence of which I can't explain in an adult. Perhaps Nikolas or others can. Therefore I would be happier considering this to be an 18 month old bird in second winter plumage, two or three years short of a full adult. But another perhaps age related feature is the white tips to the primaries. When in juveniles these white tips form a series of chevrons they are said to be diagnostic of Arctic Jaeger (Olsen & Larsson 1997). Jaegers are notoriously difficult to ID and photographs of open wings particularly underwings are very helpful in this process.

Mike Carter
30 Canadian Bay Road
Mount Eliza  VIC 3930
Tel  (03) 9787 7136




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