This 4 cy caspian gull was present at Øra, Fredrikstad today in horrendous weather conditions. It was one of those gloomy days when daylight simply did not appear. The poor light and long range to the bird pushed me into doing something I rarely do: document something with the mobile phone. I rarely (well, never) find the outcomes satisfactory, and so was the case today as well. The pictures presented hardly give a true representation of the bird as seen in the field. The photos are flat and with little contrast, but hey - they are all I have got...
This is how it was discovered, about 300 m away. Note the long legs and how much higher it seems to stand compared to the herring gulls. Most of the difference in leg length is found above the tibia, a typical caspian feature. Note also how it seems to be compressed from the sides. Also typical of the species.
Even though the birds are soaking wet, you can see that the caspian looks purer white. The head streaking was confined to the hind-neck and neck sides.
Not much to go on in this picture, but the dark eye, the white head and the (a little more) high-breasted appearance (than the herring gulls) are distinguishing features. Again - the poor quality of the photographs...Brown smudging of inner greater coverts and tertials, dark primary coverts, remnants of a tail band and, of course the bill are signs of immaturity. I believe 4cy to be correct.
Complete band (albeit thin on inner web) of P5 and bonus spot on outer web of P4 is well within the variation of caspian gull.
I hope the bird will become a long stayer so that better photos can be obtained. These hardly do the bird justice..