This evening it was much brighter than the previous two evenings but still mild and calm. The gull roost seems to be getting smaller each evening and it was a comparatively paltry affair tonight. However what it lacked in quantity it certainly made up for with quality in the form of what I thought at the time was cracking adult Caspian gull. The birds were once again quite close and the low numbers meant that one was able to get a great view of the bird: so often when they are standing around on the floods one can only see parts of the bird in the crowd. The bird had what appeared to be long spindly pink legs and a sort of aloof imperial look that Caspians have. Admittedly the bill wasn't as long or as pale as one would ideally like to have but I was convinced. Fortunately Ian Lewington put me straight: the underside of the P10 primary is diagnostic and this bird obligingly kept it on display the whole time. Whilst I knew this feather was important, I'd mis-remembered what exactly it should look like. Take a look at the photos first:
I even had a go at a digiscoped still shot though in the half light
of dusk even at ISO 800 the shutter speed was only about 1/30th sec
so I've had to over-sharpen it to compensate. Click to enlarge if you wish
Video footage - this would have been great apart from the slight tilt.
You can of course correct for this in a still photo but not so easily with video
as you have far fewer pixels to play with
On a yellow-legged gull, the P10 underside is basically a black feather with a white tip (as above). On an adult Caspian it's a white feather with a black band about an inch wide close to the tip. This will more or less apply to a 3rd winter Caspian as well with a long white tongue coming up into the black but not for younger birds. Ian reckons that this bird might come from the south-western part of the yellow-legged gull region e.g. the Iberian peninsula. Apparently they are quite a common occurrence in early December and can fool the unwary (such as myself!).
Apart from this interesting gull there were only about fifty non-black-headed gulls all told including a common gull that was barely out of juvenile plumage with just one or two of its scapulars starting to turn grey. Gulls aside, the usual suspects were about: the two REDSHANK were still present and there were a couple of hundred golden plover around still as noisy as ever. I've noticed that as well as their usual murmuring sound they also occasionally make a call that is remarkably like a green sandpiper. The first time I heard it actually thought that it was one though I've since got used to it. Talking of mimicing calls, as I was cycling down Longworth Road towards the Meadow I heard the distinct distant call of a wigeon coming from the roof tops! Of course it turned out to be a starling doing an excellent imitation.