Friday, January 29, 2021

Past couple of weeks

Since my last blog post the water levels have been up and down constantly on Port Meadow creating varied conditions for birding. On some days birds are fairly close by providing excellent views on small islands created by the receding floodwaters, whilst on other days the entire field is completely flooded resulting in a "Farmoor Reservoir" type of experience - i.e. straining trying to identify distant dots on the water. 

The floods are still continuing to pull in large numbers of roosting gulls and despite the mid-winter feel of little turnover there have been some interesting birds present. Caspian gulls have continued to frequent the roost including this smart new 1w with a few grey 2nd generation coverts.


This 2w Caspian gull roosted on a couple of evenings - an individual that I have seen previously at Appleford Gravel Pit. I picked out both this bird and the 1w above in flight as they circled over the Meadow - checking the gulls as they are flying in is something I've been doing more and more of recently and I feel it has certain advantages over trying to pick them out on the water especially if the gulls are densely packed.


Note the P10 mirrors and the white tongue at the base of P10, both good indicators for Caspian gull

The regular 2w Caspian gull that I've also seen at Farmoor has also provided excellent views although seems to have become tattier and uglier as the winter progresses.

This 2w individual is a fascinating bird with heavily chequered inner greater coverts and plain brown lesser coverts reminiscent of Yellow-legged gull. I included a photo of it in the last blog post and speculated that it was a possible Caspian x Herring gull hybrid but have since obtained much closer views and I think that option is unlikely. If anything it has some michahellis genes in it, but I think it is probably within variation for pure Caspian gull. Although it has no P10 mirrors, the structure is very Caspian-like, with a long, thin bill and handing rear belly - legs are not as short as they appear in this image as the feathers are fluffed up against the cold. Pro-Caspian features also include the relatively unmarked outer greater coverts, mantle colour and pure white underwing. Hybrids with Yellow-legged gull apparently tend to be more heavily streaked at this age.


Yellow-ringed XJNE, which I first noted at Appleford has also been present in the roost for the last few days. Despite being ringed in a mixed colony at Braunsdebra, Germany (and almost certainly having some Herring gull genes judging by the chequered greater coverts). I think it's a great-looking bird, especially in flight - really white underwing and unmarked uppertail. It is very aggressive towards the other gulls and on several occasions I have heard it call loudly as it flies around. I have rarely heard Caspian gulls call but got some good "training" in London over Christmas with birds coming to bread and XJNE certainly sounds like a Caspian gull - a braying "honk" quite different to Herring gull. Personally I am of the opinion that most of the large white-headed gulls are just one superspecies complex so the question of "where to draw the line", which many birders seem to be obsessed about with regard to Caspian gulls becomes less relevant to me. I'm just happy to enjoy a bird like this that's come all the way from Germany to winter here.






This 3w bird was also an obvious Caspian x Herring gull hybrid, with a very Herring-like primary pattern. Note the brightly coloured bill - usually a pallid greenish-yellow in Caspian gull at this age.

Continuing with the hybrid theme was this brute of a 2w argentatus Herring gull. Although not an obvious Viking gull I would bet money on it being from the far North and there being some Glaucous influence somewhere down the line - all the feather markings are so finely vermiculated, it has a Glauc bill, uniform latte-coloured underparts and very pale tertial centres combined with brown pale-tipped primaries. The tail pattern, however, was quite Herring-y. A striking bird.

There have also been a few Yellow-legged gulls in the roost - I rarely bother to photograph these but the 1w was quite a smart bird and the adult had a slightly peppered iris colour.

1w

Showing tail pattern characteristic of Yellow-legged gull

Adult

Of interest also have been continental interemdius Lesser Black-backed gulls - there have been a few of these in the roost recently, which generally have a darker mantle tone and more attenuated structure than graellsii.

Under lockdown restrictions I have avoided general county birding and largely kept to Port Meadow, which I'm lucky to have on my doorstep. However, since my Appleford patch is within cycling distance I decided to visit last week to check how it was getting on. There are currently very few large gulls on the Gravel Pit itself and instead they are now loafing in a flooded field just Northeast of the railway crossing. One of the first birds I laid eyes on was this adult Caspian gull - always hard to tell with the adults (especially as so many have similar bill markings) but I feel that this is a bird I've seen before, with comparatively short yellowish legs...

This 1w was a new individual to me and a nice classic bird.

This 1w brute has been around all winter and every time I see it I notice more Herring-y traits... it's comparable in my opinion to XJNE although has slightly less covert chequering.


So in conclusion a solid couple weeks of gulling - no stand-out bird, unlike the excitement at the beginning of January, but still pretty rewarding. Nine Caspian gulls (four 1w, three 2w, 3w and adult) plus two hybrids is pretty good going for the Meadow by the end of January - clearly it's been an exceptional winter for this species in Oxfordshire. Adam managed to grip me off with a 1w Med gull in the roost tonight though which I failed to connect with despite being on site. Will have to hammer March passage for that year tick...

Finishing off this post with an image of a fabulous Port Meadow sunset.



3 comments:

  1. Lovely set of gulls there, Thomas. 😊 👍
    I liked your comment re 'super-species' complex. Pretty much how I think of them all too.

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  2. I'm finding your blogs fascinating Thomas, even though I just can't get my head around the nuances of Gulls. When are you beginning giving Gull ID classes? I'm in for the first, and probably a few more after. Good work! Don't take too long to write your definitive guidebook please, I need it now.

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  3. Excellent blog Thomas I learned a lot from it - gulls are my nemesis ! count me in on Nick's suggest ID course!!!

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Eyestrain at Farmoor

For my Oxfordshire birding I have somehow ended up adopting three patches - Port Meadow (the original and the best), Appleford (because of t...