What did I say? 'no problem as to species'. Well that's the problem with blogging, your mistakes are there for all to see, and some things are just above my pay grade. Without photos I might have got away with it, but then who'd be reading this?
Of course, I did consider Kumlien's at the time, but it looked so pale and the primaries looked so white that the thought didn't last. When Martin Elliott saw a few of photos he came back with 'looks more like Kumlien's to me'. I went back through the nearly 300 photos I took, selected all those showing an open wing and increased the contrast and saturation somewhat. Here are a few of the more informative ones; as usual, clicking on the photo will enlarge it.
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
Obviously the Sun was bright and the bird was backlit, I compensated as well as I could but some of the whites are burnt out. Added to that this is a very bleached individual, very much paler than a well-marked Autumn juvenile, and as such perhaps unidentifiable with absolute certainty. Nevertheless, I think it's clear that there is some grey-brown shading on the outer primaries which, since an Iceland Gull in this state should show a more or less pure white outer wing, is a good indicator of Kumlien's - '
brownish wash on outer primaries versus evenly pale primaries on Iceland' (Howell & Dunn 2007), and
'dark outer webs create darker outer wing than in glaucoides, appearing concolorous with inner wing and typically plain, with brown wash centred along primary shafts, spreading onto both webs' (Olsen & Larsson 2004).
The mostly dark bill is suggestive of Kumlien's,
'(Kumlien's) bill typically blackish with dull flesh to flesh-pink basally...
(Iceland) bill often brightens to flesh with fairly clean-cut blackish distal third' (Howell & Dunn 2007), and
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most kumlieni have black bill with slightly paler brown base...most glaucoides have bicoloured bill' (Olsen & Larsson 2004).
The tail was quite well marked for such a bleached bird, showing darker centres and diffuse barring, paler towards the tip with thin dark sub-terminal marks.
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
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| probable Kumlien's Gull - Topsham 1/4/2014 |
While not conclusive - as usual there's too much variation - this tail pattern favours Kumlien's, Iceland typically has a plainer tail.
So a Kumlien's then? Well I'm pretty convinced at least although I wouldn't bet my life on it. Sometimes, with some birds, certainty is never going to be a rational position. I doubt now if it would have made much difference if the light had been better, and at least I didn't need to worry about shutter speeds. While a close look under flat bright light would have brought out more detail - and made for some much nicer photos - I still think it would be nigh impossible to be 100% certain with such a bleached bird.
Many thanks to this blog's Gull Consultant Martin Elliott for his informed and always patient advice.
It goes without saying that I'd love to hear other views on this, so comments welcome as ever.
Edit: Dave Stone just managed to get down to see the bird before it flew and got a few photos. This shot of the spread wing shows rather more detail than mine and would appear to put the matter beyond much doubt.
http://davesbirdingdiary.blogspot.co.uk/2014/04/iceland-gull-larus-glaucoides-topsham.html
References
Howell, S.N.G. & Dunn, J.L. 2007.
Gulls of the Americas (Peterson Reference Guides). Houghton Mifflin Harcourt.
Olsen, K.M. & Larsson, H. 2004.
Gulls of Europe, Asia and North America. A & C Black.
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