Yesterday afternoon I spent some time at Cotesbach landfill site near to Shawell and I had one of my most successful sessions to date. In all I read 27 colour-rings and had close views of two Caspian Gulls, an adult that I've seen before and a new fourth-winter. I also saw what at first appeared to be a second-winter Caspian Gull, but under close examination it didn't tick all the boxes. It was not quite elegant enough and its coverts didn't look quite right either. I decided it might just have a few Herring Gull genes, so best to add it to the hybrid list.
Compared to the adult Herring Gull, to its left, the Caspian Gull has a smaller clean white head; smaller and darker eyes; a thinner and more parallel edged bill; longer wings; greyer legs and is fuller breasted. The long white tip to the longest primary feather (P10) is just visible in the photo above and zoomed up the white tong is also just visible. A small dark mark can be seen on P5. Its leg length was impossible to see due to it standing behind the dirt, but it did appear to me to be longer legged than the other gulls.
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| One of the Colour-ringed Gulls - Dutch Ringed LBB Gull (FAUK) |
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| Adult Caspian Gull |
Compared to the adult Herring Gull, to its left, the Caspian Gull has a smaller clean white head; smaller and darker eyes; a thinner and more parallel edged bill; longer wings; greyer legs and is fuller breasted. The long white tip to the longest primary feather (P10) is just visible in the photo above and zoomed up the white tong is also just visible. A small dark mark can be seen on P5. Its leg length was impossible to see due to it standing behind the dirt, but it did appear to me to be longer legged than the other gulls.
