Tuesday 14 February 2012

Iceland Gulls - Ageing two birds

My thanks to Les Bird for kindly supplying these images, you can see more of them at http://cuckmereousebirdblog.wordpress.com/  These two birds are present at Newhaven Harbour, East Sussex, the photos were taken on 23 January 2012.

(Iceland Gull - © Les Bird 2012)
(Iceland Gull - © Les Bird 2012)
(Iceland Gull - © Les Bird 2012)
This bird was aged as a second-winter, but is a pale individual. The light eye and pale bill, with an approximately 30-40% black tip, are good pointers to rule out first winter. The lack of strong patterning also rules out most first-winters, but some very pale ones can also look this bleached, and as mentioned above this bird is paler than the average second-winter. Second-winter birds also typically look slightly more brutish than first-winters, the pale eye giving them an expression more similar to Herring Gull, I find first-winters can have more of a cute, Common Gull-like expression. However, the rounder head and fairly slender, long-winged shape, plus their smaller size by comparison, means a second-winter glauciodes is still a lot less brutish than hyberboreus in any plumage.

(Iceland Gull - © Les Bird 2012)
(Iceland Gull - © Les Bird 2012)
This bird is an easy first-winter. The ratio of black:pale on the bill is greater than the second-winter above, and the dark eye gives it that cute, docile look reminiscent of Common Gull. The brownish patterning on the mantle, coverts and tertials is typical of first-winter Iceland Gull and, rather than being at the pale end of the glauciodes spectrum, this is a fairly average bird.

Separation from Glaucous is fairly straightforward. The wings look longer, extending beyond the tail, and the bill is shorter, weaker and less hooked than Glaucous. Iceland has a rounder head and larger eyes, with a deep breast and short legs when standing. In flight Iceland is more elegant, handling strong winds as well as a Kittiwake, and is proportionately longer-winged than Glaucous. Seen side-by side, or with other gulls, Iceland is normally slightly smaller than Herring Gull, while Glaucous is larger than Herring, almost approaching the size of a Great Black-back Gull.

And if you want to separate these two from Kumlien's, the flight shots of the second-winter bird show no grey colouring in the primaries, and the first-winter bird has both a bi-coloured bill and very pale primaries. This should probably rule out about 99% of the hybrid swarm, but please don't ask me to write about the 1% that are inseparable from Ice Gull, I still enjoy gulls at the moment!

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