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, September 07, 2009

Caspian Gull; Skeppsbrön; 7th September 2009

Caspian Gull 1st Calender. Structure is often key with these birds, note the long primary projection here. Also note the long, all dark, fine bill with needle point. Apparently it is not all that common to find a Caspian with such an obvious, textbook bill.. In additon a relatively small head on a long slim neck, all classic Caspian features....

Note the tertials, though broadly tipped pale there is no notching as you find in Herring Gulls of the same age. Yellow Legged Gull would show much finer pale fringes than displayed on this bird...

Scapulars, note the fresh feather on the top row, the paleness of the grey and shape of its dark centre, a major aid in separation from fuscus Lesser Black Backed Gull. The length of the rear scapulars is also telling, fuscus have much shorter, more compact scapulars than this bird....

Wing Coverts, finely patterned under large lower scapulars. Compare these to the more boldly patterned coverts displayed by both Argentatus and Fuscus.

Preening, a good view of the tertials and scapulars here....

Relatively pale haed and breast a useful feature and aid to picking the bird out initially, the bill though was the standout feature...


Note the warm cinnamon tones on the mantle in this picture, fine for Caspian, never seen in fuscus of this age which are always colder toned.

This bird now identified without doubt as a Caspian Gull! Writing this the day after and have had huge help and expertise from several gull experts, all of whom are in agreement that this is a good Caspian Gull, 1st Calender bird. Many thanks to Lou Bertalen, Jan Jörgenson, Christian Mihai, Hans Larson, Ola Marklund, Oscar Nilson and Karl Gustav Sjölund for their input and expertise on both Svalan and Birdforum. Have tried to summarise many of the comments above in the noted under the images posted here. This bird has been a real eye opener for me and I have learnt a great deal from the bird.
Features securing the identification as a 1st Calender Caspian include the long, dark bill without a pronounced gonedeal angle, pale head and breast, long primary projection, warm tones on the mantle helping to rule out Fuscus Lesser Black Backed Gull, long rear scapulars and the fres scapular on the upper row, patterned as one would expect of Caspian Gull.




1 comment:

Oskar Nilsson said...

Hi Alan, this is absolutely a 1cy cachinnans. Nice job! Keep on posting nice pics on Svalan :-)