Friday 13 February 2015

1stw Vega, Mongolian and Taimyr Gulls; February 8th

One really good thing about looking for gulls at Tsu city is many of them can be approached quite closely, certainly far better views can be had than in Osaka. There are large numbers of very distant gulls out on off-shore sand bars too but there are always enough birds close at hand to sustain interest. A group on the beach is worth a flock on a sand bar, as the saying ought to go.

As an aside, one thing I really like about first winter gulls (apart from their appearance) is that they're always willing to stand up to the crows. While to gulls loafing time means just that, bathe, preen, take a nap, to crows loafing time seems to be all about seeing how many gulls they can disturb. Normally I'm very pro-crow but when it comes to gulling in Osaka they can irritate the hell out of me, I've seen the whole gull flock prematurely head out into the bay too often... leaving me with hours of daylight and nothing to look at. At risk of sounding anthropomorphic, it's as if with age gulls would rather just move out of the way than play the crows silly games. But it's not anthropomorphising to say this does seem to be a form of play to the crows, they're focused on food in the morning but from mid-afternoon there's a real shift in behaviour and a small number of birds will drop into the gull flock and walk directly at the nearest sleeping or preening gull and peck it to get a response if it hadn't already moved out of the way, then on to the next, then another. There's no obvious benefit for the crow. When there's a dead fish involved the difference is striking and a single gull is more than a match for two or three crows. The only way the crows win is by a few birds forming a circle and taking turns to rush in from opposite sides preventing the gull from feeding until it eventually concedes and leaves the fish to the crows. And that's when crow cooperation goes out the window. But first winter gulls don't back down, not even when there's nothing to defend.

This Taimyr is a good example.





The least common of the regular large gulls here is Mongolian. Last weekend I saw one first winter, seeing more than a single first winter is fairly unusual and I don't think I've ever had more than three in a day.

First winter Mongolians invariably stand out even at very long range because of their very pale rather uniform appearance. The largely white coverts and pale grey to whitish saddle with narrow dark centre line and sub-terminal bar produce an over all appearance usually only matched by very worn individuals of other taxa.

Vega is by far the commonest of the Herring-type gulls here so unsurprisingly this is where I see the widest range of plumage variation on a regular basis and I'm far less likely to want to invoke the dreaded H-word. Whereas seeing far fewer of the others, it's less easy to know just how odd an odd individual might be and whether it is or is not within the normal range of variation.

I saw three first winter Vegas at close range that day and these are shots of the three.

Vega 1: A basically brown bird with boldly chequered coverts and tertials. The underparts are typical, dark but mottled rather than smooth.

Vega 2: A greyer version of the previous bird and more the norm. This tertial pattern also occurs more often. 

Vega 3: An even paler bird, particularly the underparts.

Two Taimyr Gulls, closer views below.

Taimyr 1 (left-hand of the upper two): On many birds the paler areas in the coverts, especially the medians, can be dull and lack contrast creating a darker-looking wing.

Taimyr 2 (right-hand of the upper two): Slightly more variegated outer greater coverts on this bird and much paler-centred medians.

Vega 2: Prominent inner primary window. Underwing mainly dark with distinctly barred axillaries.

Vega 3: The palest bird.

Taimyr 1: The axillaries are usually subtly marked like this.

Taimyr 1: Lack of obvious primary window and dark-based greater coverts create a darker and more uniform upper wing in flight.

Taimyr 2.

I've previously posted images of juvenile and first winter Taimy Gulls here.

2 comments:

  1. Your ability to ID immature gulls of recently split species puts mine to shame................there are lots of gulls on the coasts around me, maybe I should look a little closer at them..................

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    1. Split, not split or potential to split, depends who you follow. But looking at gulls is good fun (honest) even though there'll always be some you can't confidently ID. I'd love to have some of the opportunities you've got up there.

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