Alan Dalton post's birding diaries and original artwork from Sweden. Established in 2006, this now long running blog is now a complete overview of my birding experiences. As an artist I greatly enjoy sketching birds in the field and you will find a wide selection of that work here, from fieldwork to finished paintings. I am very passionate about my artwork and try to depict birds in their natural habitat, as I see them in the wild. My artwork is for sale and can be viewed at http://www.alandalton.net/
As regards to my photography, since 2008 I have used a Nikon D90 DSLR camera coupled with a Sigma 150-500mm OS lens for since March 2012 for bird photography, all previous images being digiscoped. Regarding sound recording, I have been usung a Telinga Stereo Dat Mic and parabol to record birds in the field, coupled to a Marrantz 661 digital recorder, a superb piece of kit. Interest in butterflies, dragonflies and damselflies has recently seen the accquisition of a Sigma 150mm macro lens. I hope you enjoy the blog and please feel free to leave comments or contact me at alandltn@gmail.com

Monday, August 11, 2014

Early moulting juvenile Argentatus Herring Gull at Skeppsbron; 11th August 2014

 A large, chunky juvenile gull this, which gained my full attention after I noticed the newly moulted scapulars, which can clearly be seen here. Herring Gull rarely shows moult this early this far north and this can be a good indicator of a Yellow-legged Gull. Tertials seems not as dark centred as I would hope for in YLG, also the greater covert's seem rather piano keyed and a better fit for Herring Gull? Head looks rather pale with a dark mask around the eye, not a bad fit for YLG? Note the slightly worn coverts on this bird...a very interesting individual.


 Could these tertials be within what one might expect on YLG? How about those greater coverts? Both seem perfectly acceptable for Argentatus Herring Gull. Furthermore I would expect a Yellow-legged Gull to show reddish brown tones around the mantle and hindneck, a slightly deeper base to the bill and a whiter head., perhaps a slightly longer primary projection at rest. On this side just a single scapular is moulted.


 Again the other side, which again lacks reddish brown tones on the mantle and hindneck as mentioned. The pale fringes on the tertials are notched and extend in to the greater coverts, supporting Argentatus Herring Gull.


 In flight, the only decent flight shot I got. Note the rather broad tailband, rather white inner tail and rump, not apparently unlike what one would expect in YLG? I was quite struck by the tail pattern and rump as being quite good for YLG. Note however, a small number of Argentatus  do show this rather Mich like tail pattern and the white tips to the tail feathers are a litle thin and irregular for a Yellow-legged Gull.  In flight the greater covert's look ok for YLG, but not the inner primaries. Here the feathers look pale, with light lozenges on outer webs of P1-P3, better for Herring Gull. This for me is the clinching feature and leads me to the conclusion that this is an early fledged Argentatus showing early scapular moult and a tail pattern that is rather Mich like. Note here the flanks are rather finely marked, lacking the large blotched marking usually associated with Yellow-legged Gull.


At rest here, looking too short winged for a Yellow-legged Gull. Again note the classic, notched greater coverts, supporting Argentatus. All things taken into acount this seems fine as a Herring Gull, albeit one that shows some characteristics of YLG. Here in Sweden, the presence of these big northern Argentatus types make identification of Yellow-legged Gull even tougher, due to structural simularities in the first instance, whilst birds showing Mich like tail patterns and darker plumage only serve to further compound the identification on occasion. Careful observation, patience and assessing the full suite of features involved require good views and experience and not a little objectivity. 

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