Sunday 11 August 2013

Latest Update From Shawell

I've made quite a few visits to Shawell A5 Lagoons and the nearby landfill site already this month, which has resulted in twenty four colour ring readings. These were all sported by Lesser Black-backed Gulls. Most were ringed in the United Kingdom including two from Guernsey, but others were ringed in Germany, Holland, Iceland and Norway. One of the more interesting life histories was that of VV4T. This one was originally ringed at Rainham Tip, Greater London during late 2011, but shortly after it was holidaying in Western Sahara. I'm still awaiting the report on the Icelandic bird, but hopefully that will be an interesting one. I did see a couple of colour-ringed Herring Gulls, but the rings were un-readable due to having mud covering some of the ring.

Amongst the LBB Gulls this weekend were some really dark individuals. These are of the sub-species Larus fuscus intermedius, which are birds that nest to the east of Britain mainly in Norway. The sub-species Larus fuscus fuscus (Baltic Gull), which nests in eastern Scandinavia is the darkest backed of the group with the whole wing looking black. The sub-species that nests in Britain is larus fuscus graellsii and this one has dark grey upper parts that contrast clearly with the blacker primary (wingtip) feathers. The blackest of the gulls I saw yesterday also had very long wings which is a feature of the sub-species Baltic Gull. However, the organiser of the Norwegian gull ringing scheme stated to me that fuscus type LBB Gulls are nesting near Tromso. From this I take it that some Larus fuscus intermedius look like Larus fuscus fuscus. I have seen coloured-ringed LBB Gulls from Tromso at Shawell a few times, but they weren't as dark as the bird in the photo below. Hopefully a colour-ringed Baltic Gull will be seen at Shawell sometime, as this is probably the only way of being certain of its origins.

The bird in the photograph below is much darker than others I've seen that were ringed in Norway as intermedius, also its quite long winged.

 Larus fuscus but which one?  (lying down)
There are plenty of gulls in the area now with a least 2000 of them being Lesser Black-backs. About twenty of each Herring and Yellow-legged Gulls are using the site, with a few hundred Black-headed Gulls. Great Black-backed and Common Gulls are the least numerous of the species at the moment with usually about two of each.

The Yellow-legged Gulls are mostly adults or sub-adults, but all ages are represented. The least common are juveniles and first-summers.

Yellow-legged Gull
Yellow-legged Gull

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