Thursday 4 January 2018

barrovianus Glaucous Gull?! In Mie!!!

I think myself lucky to see Glaucous Gull down here. If I go gulling in the Matsusaka/Tsu-shi (Mie) area, I'd hope to see one per winter but if I stuck to Osaka it might be one every three or four years.

This winter I've already had two! An adult flyby in Matsusaka on 12 Nov which seems a very early date for down here. Then yesterday I found this bird way out in the bay. It was with a group of Vega all foot-paddling along a fracture line along the surface of the water, smooth and glassy on one side but choppy on the other, like a flock of giant Wilson's Storm Petrels. They were little more than specks even in the scope but there was something about the way it easily moved along the line, effortlessly looping back from time to time, put the Vegas to shame. A Glaucous would be great... but an Iceland would be unbelievable; even 'just' a Thayer's.

It was worth waiting. There was a pretty good chance they'd come in to the beach eventually. Maybe not this beach but it was worth waiting. After a while they settled on the sea with the current slowly drifting them south. After about another 20 minutes uncomfortably staring through the scope to keep track of their position they took flight and, "Yes!", they were heading in to this beach.

It turned out the wait was really worthwhile because this was a really interesting gull. The comment in Olsen "Jizz-wise, certain small females combine Herring Gull head on Iceland Gull body." seems to sum up this bird very well. Now, I've never seen a barovianus... it's is a subspecies tick for me and, large gulls being large gulls, there's always room for doubt. However I'm pretty sure this ticks all the right boxes. For once I'm not even worried about the risk of a hybrid.

Head on, as the gull was flying directly towards shore with a few Vega, it looked long-winged. That may not be difficult when compared with Vega but Glaucous invariably manages to fail. Once on the beach it was much easier to assess size; it's smallish Vega, ie not the smallest gull in the flock but it could be dwarfed by a large Vega. At rest the gull is surprisingly attenuated with a long primary projection and little in the way of a tertial step. A Long projection, but not Iceland long. At times the head looked more angular with a sloping forehead, which made the short bill look longer, but more often the head was rather domed resulting in a ridiculously short (for Glauc) bill, short but too deep and heavy for Iceland. Whatever the head shape there was never any getting away from that piggy eye that looks so at odds with the often doe-eyed expression of Iceland. Coming back to the short bill, it has an extensive black tip, black runs along the cutting edge of the lower mandible and the upper is dusky towards the base! This gull is confused, either as an individual or a taxon if this is barovianus
as I suspect. But I hope the images will be worth a thousand words...

Ah... the danger of the single image. I think I might have been able to get away with claiming an Iceland Gull if this was the only image I had. The primaries look really long and the rear end quite attenuated, the later aided by tucking up the belly to produce a flat keel... even if it does show a little too much tibia for my liking. At this angle the telltale eye isn't giving the game away and just look at the colour of that bill. Outrageous!

By contrast this is the most Glaucous-like image I have. The forehead is very long here which imparts a longer-billed appearance than the gull usually gave. The primaries are crossed which lessens the apparent length of the projection. During the time I was there the light changed from bright sunshine to black rain clouds, back to sunshine before a premature dusk. A bit tricky settings-wise with a white bird and I spent almost as much time fumbling with the camera as watching the gull.

Pretty much looks the Glauc part here but throw in a larger eye and the gestalt would alter appreciably.

The undertail and coverts to follow the uppertail in the previous image.

A quick bathe before coming ashore. It's next to a substantial but hardly monster-Vega.

It doesn't look much bigger here behind that male-type.

Joining the 'hen-party' it fits in much better size-wise.

This just doesn't look like an obvious Glaucous Gull.

So. Do I get a subspecies tick? Is this a barrovianus Glaucous Gull?

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