Monday, 15 January 2018

Common Gull

A weekend spent once more in the company of gulls, and thank Heaven for it! I got my weather all wrong this weekend (or rather the CWB did) as the forecast was for gales on Saturday. I thus chose Friday to head north into Chiayi county gulling, only to meet the gales head on and to find them all passed come Saturday! The day was nevertheless an interesting one, with more big gulls around than usual; the best find in amongst them being a first-winter Common Gull Larus canus. As the upcoming Malling Olsen guide will seemingly choose to treat 'Kamchatka Gull' as a distinct taxon, it's going to be worth investigating with care precisely which one of the two this one is (as both heinei and kamtschatschensis could occur here). However, that's a big pile of reading which will have to wait until some point in the future before it finds itself getting done!

Other gulls around were Taimyr Gulls Larus taimyrensis (obviously), and a bunch of essentially juvenile birds chose to move through the area late afternoon on their way to roost. The two below I've photographed already this winter (the bird with the nick in its right wing being readily recognisable). These birds were followed by any number of adults (or near-adults), all still moulting.

There was a brief moment of excitement when a new Mongolian Gull Larus mongolicus showed up. This one really did appear to have streaky wingtips and an all-white tip to P10; pointers towards something better! However, it transpired that the apparent streaks were just unusually pale shafts; a shame as this bird really does have limited black in its wing (to P5 rather than to P4 as is usual). (Note also how the tips to P5-4 are worn, suggesting they have been 'on' for some time.)

After the cold and wind of Friday, I spent Saturday locally and it was rubbish, so on Sunday I returned to Dung Shr for yet more gulls. It was a surprisingly nice day, sunny and with little wind, and this seemed to result in there being fewer gulls present. The Common Gull remained, though, but getting photos of it seemed more difficult for some reason.

The best thing about Sunday was finally getting clear photos of a large gull that has been bothering me since the day it arrived, but has never come sufficiently close to get shots of its upperparts. This curious individual seems to show features of both Taimyr and Mongolian Gull, though I do not believe it to be a hybrid. In favour of Taimyr Gull are the unmarked greater coverts and rather dark window on the inner primaries. However, in favour of Mongolian are the early scapular moult (all are replaced), the rather worn wing (including tertials, which have broad crescent-shaped tips rather than narrow and more even pale fringes), the tail pattern (with narrow tail band not reaching the uppertail coverts and wavy 'inner' bands), and the wing shape (very broad with short triangular 'hand'). The bulk and size would also seem to suggest Mongolian Gull, which is what I believe this bird to be (and have indeed been calling it such since it arrived).

As my camera was rapidly filling up with images on Sunday and I did not want to spend yet another evening deleting unwanted photos, I chose to head south before I took any more shots and stopped on the Tseng Wen River for the wintering Hen Harrier Circus cyaneus. As this had been on the south side of the river late Saturday afternoon, I chose to try there instead of the north side. Wouldn't you know it? It was on the south side, but chose to fly directly across to the north side the moment I showed up! Still, I did manage at least some record shots of it.

I've got plenty of experience of birds such as this one (which delight in playing 'silly buggers') and took this as a not so subtle hint to leave it alone. This may well now happen, though I'll not be doing the same with gulls, which will now likely clog up this blog until the winter comes to a close! Above photos taken at Dung Shr, Chiayi County, and on the Tseng Wen River, Tainan City 12-14/1/18.

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