Friday, 15 August 2014

Juvenile Yellow-legged Gulls Plus Another Sighting of One of the Juvenile Casps

During the summer months, when I can, I like to have an early evening visit to Shawell on at least one day. This Wednesday evening I chose to look into the quarry next to the landfill site and see what was about. A small group of gulls, mainly juveniles, were loafing around by one of the three small pools. A couple of juvenile Yellow-legged Gulls were with them. I tried to Digiscope them, but it was quite difficult as the sun was shining straight on to my LCD screen. In the end I did manage to get a few records shots. The one in the first photograph shows the features quite nicely: large and robust, a large pale squarish head with an eye mask, a short but deep black bill, large brown scapular feathers and dark brown tertials with fine pale edges.

Juvenile Yellow-legged Gull

The second individual was noticeably larger and its greater coverts were distinctly notched and some pale buff markings were visible on the tertials. Although most juvenile YLG's have just a fine pale edge to the tertials, some have notched tertials a bit like juvenile Herring Gulls. The brown of a juvenile YLG is much redder in tone compared to the frosty grey of most juvenile Herring Gulls. Also even though it is not that obvious in the photo below, its head was much whiter than the juvenile Herring Gulls present. The young Herring Gulls are mostly still begging for food from adults and as such are obviously much younger and fresher looking.

Juvenile Yellow-legged Gull
The Same Juvenile YLG as Above

The photo above shows the opposite side of the larger juvenile YLG. In this image its head looks paler and you can see that it has already moulted some feathers and so it is on its way to first-winter plumage.

After grilling the juv. YLG's, I noticed a young gull with a pale head and its saddle was also very pale looking, because of the broad pale edges to the feathers.

Structurally it was very different to the juv. YLG's, more elegant and longer legged. Unfortunately it stood facing me and wasn't very photogenic in that pose. A flap of the wings revealed its very white looking underwings and I managed to see it very obvious black tail band, which contrasted with the very white upper tail coverts. So, long thin legs, long wings, white underwings and the tail pattern all seemed to point towards it being a young Caspian Gull. It flew on to the water where I was able to get some images, which clearly show the jizz of a Caspian Gull. Some of its feathers are quite faded, but it still appears to be a full juvenile. The bill shape is good, long and parallel with a shallow gonys angle.

I now believe this is the same juvenile that I first saw on 09/08/14. 

Juvenile Caspian Gull

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