A very distinctive bird, one of only a few with such extensive adult-type grey in the saddle. Features like the greater coverts bar can look lighter or darker depending on the light conditions of course but the uniformity is always eye-catching on most birds. Having said that the extent of the bar is variable and though Vega is supposed not to show a coverts bar beyond the small group of outermost coverts (usually hidden at rest) they can show more solidly dark-based feathers across the outer coverts. The inner primary window can also be affected by lighting and how widely the feathers are splayed. At this time of year many Vegas are very white, similar to Mongolian Gull, with a window to match and after looking at them a 'standard' Vega might seem relatively dark. A reasonably reliable distinction is the tail band which in Taimyr is a similar shape to that of Mongolian, narrowing outwards with least black on t6. Vega usually shows far more black in the bases of the outer feathers. Sometimes this is even apparent at rest when any bird with clear laddering along most/all of the t6 length will be Vega.
With a much bulkier bird, still with darker lesser coverts and distinctly patterned saddle.
Most Taimyr still have a largely black bill at this time of year whereas many Vega have an obviously pale-based bill with contrasting dark tip. This hulking Taimyr was strikingly pale-billed compared to all others seen over the three days.
A fairly typical Vega present at the time showing the different tail pattern, mainly black to the base on the inner four and to the base on the outer webs of the outer pair. The window is pale and as is often the case by this time the outer primaries are faded and browner, those of Taimyr look fresher.
Vega in the foreground, Taimyr behind. The difference in window is most obvious when the wings are only slightly open.
Another attractive grey-backed bird in the foreground (Bird 1 behind it) and a Vega to the right. Prominent laddering along the length of t6 is easily seen on this Vega, the almost Glaucous-like bill pattern is also very unlike the two Taimyrs.
On the right (Bird 3 on left), this bird had a 'bald patch' in the in the centre of the coverts bar.
The bird on the left has unusual prominent moons and also very short thick lozenges giving the window an interesting pattern. Even in the lower shot with the spots stand out with the primaries bunched.
Though the tertials look broadly fringed white here, this is a result of two feathers aligned in such a way as the fringes merge into a single broad line.
It isn't all plain sailing though, as with any taxon there are going to be some less clear-cut birds. At first glance this is an obvious such example, pale-based bill, no coverts bar, the retained juvenile scapulars have a bold oak-leaf pattern. A bird like this would be a lot easier to overlook but give it a little time and the coverts bar is there, the bill isn't so exceptional and most birds do have this basic pattern in the scapulars, if slightly less indented. No doubt there'll be others that won't give up there true identity so easily.
Those scapulars look odd at first glance.
If anything, even more like a Vega in this image.
Not only does it have a coverts bar but it's surprising long given how difficult it was to see initially.
In flight the primary window is dull inkeeping with Taimyr and the tail band narrows towards t6.
Just to round this off, I took this shot yesterday (April 2) and in the background four of the five gulls are yellow-legged adult Taimyr. They really are quite common at this time of year.