Yellow-legged Gull Larus argentatus/cachinnans michahelis, Dogsthorpe Star Pit, 27 September 2001
Video grabs by Brian Stone
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PBC Gallery Yellow-legged Gull Larus argentatus/cachinnans michahelis, Dogsthorpe Star Pit, 27 September 2001 Video grabs by Brian Stone |
This Gull looks to be a full adult. It gave superb views. Primary moult distinctly more advanced than other large gulls present with P10 well grown but still well short of P9 which is also still growing. P10 shows extensive black before white mirror and no tongue is visible. There is a black band between the mirror and white tip. P9 has no white mirror and P5 has strong black subterminal mark. Closed wing shows 3 well spaced white primary tips and the rear end looks attenuated even at this stage of moult (P9 and P10 will grow to produce a longer wing tip eventually). Dark secondaries and inner primaries are also visible here. Also has a good, sturdy, heavy-tipped bill.
What cannot be seen from these images is the bright orange/yellow legs and the mantle shade. Direct comparison was possible with a number of adult argenteus and graellsii and it was mid-way between the two, perhaps a shade darker than Common Gull (although none nearby).
Helpfully, this bird is at pretty much the same stage of moult as the first illustration on p39 of British Birds Vol 90, Nos 1&2 (Jan-Feb 1997).
Some have commented that the head streaking looks quite extensive. It is within the range for michahellis but could also match Atlantis.
Other michahellis pictures: November 2001; October 2001
Wing well extended showing P10 very well and no white or grey tongue as would be visible in cachinnans or argentatus. There is no pale area between the grey and the black on any of the outer primaries.
P10 showing well here directly in line with P9 which falls just short of P8 (the current wingtip). The black subterminal mark can be made out on P5.
Another view of P10, left wing this time, showing the white mirror and quite thick black, unbroken subterminal mark.
All images are copyright.
