Tuesday 25 August 2015

Shawell Update

Juvenile Yellow-legged Gulls (Larus michahellis) are still occurring at Shawell although many of them are well on their way to attaining their first-winter plumage. This summer the influx of juveniles has been on a larger scale than in previous years.  Presumably there will be even more Yellow-legged Gulls of all ages visiting Shawell in the years to come.

A mixture of plumage characteristics and jizz make most juvenile Yellow-legged Gulls fairly easy to identify. Some are real monsters, but many don't stand out amongst the juvenile Lesser Black-backed Gulls on size alone. I saw the first juvenile Yellow-legged Gull at Shawell on July 4th and my best count so far is eleven at one time.

Juvenile Yellow-legged Gull, Shawell A5 Lagoons

The juvenile below has been present for a couple of weeks. It has already moulted its scapulars and as you can see its coverts are very pale. It is a real eye catcher as it really stands out because of the amount of pale feathering and its large size. The short thick bill and large heads of this species are obvious on most juveniles, as are the really large lower scapulars of fresh juveniles (see image above).

First-Calendar Year Yellow-legged Gull Moulting into First-Winter Plumage

On Saturday August 22nd the gulls were quite distant preferring to sit on a large mound in the quarry. Many were hidden from view, but the Caspian Gull in the image below wandered in to view. It is most likely to be a third-summer (4CY), as it appeared to have some remnant black feathering on the alula. Although it is said that this can be present into adulthood.

Caspian Gull, Shawell, 22/08/15

To give you an idea how good my new Swarovski scope is, the Caspian Gull in the picture above was on top of the mound in the photo below. As you can see using a 50mm lens you can hardly even see the gulls. I could even read colour-rings at that range. Sadly this is the typical distance I have to work with at present.

Shawell Quarry
The only other birds of note recently were a pair of Ruff at the A5 Lagoons on 19/08/15.

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