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Identification of Juvenile Yellow-legged Gull L. michahellis continued...
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| The final juvenile, actually moulting into first-winter, was at Southwold on August 17th 2000, and is compared with another at the same site the next day. This was a classic michahellis, in structure, plumage and moult, and can be identified fairly easily. Figures 9, 10 and 11.
• The head is white with some streaking, some forming a bandit mask, as is the underparts.
• Some (quite a number, and too many for Herring and Lesser Black-backed) of the scapulars have moult, and show a strongly notched pattern.
• The close-up shows the amount of wear to be expected on a michahellis by mid August. And also, once again the variability of the pattern of the tertials and greater coverts. The notching appears to extend along the tips of the outer greater coverts and is more reminiscent of smithsonianus and cachinnans.
• In flight the tail band was clean cut, and the outer rectices largely white with a very small amount of black near the tip.
• The legs are a paler flesh-pink.
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Fig. 9 Juvenile Yellow-legged Gull, Southwold, Suffolk, August 17th 2000 © Brian J Small
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Fig. 10 Juvenile Yellow-legged Gull, Southwold, Suffolk, August 17th 2000 © Brian J Small
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Fig. 11 Juvenile Yellow-legged Gull, Southwold, Suffolk, August 17th 2000 © Brian J Small
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In summary, with experience it is possible to identify juvenile and first-winter Yellow-legged Gull with relative ease. There is initially a sense of ‘gut-feeling’ about picking the odd one out, on overall quality and structure, which once learned will help. However, crucial features which need detailed examination in order to confirm and to make sure it is not just a large Lesser-black-backed Gull are: the pattern of the tail; the structure and plumage pattern of the head; the moult timing and pattern of first- and second-generation scapulars; the pattern and wear of the tertials; the pattern, moult and wear of the greater coverts.
Finally, the moult of the scapulars, some tertials and inner wing-coverts is rarely complete, being suspended until the spring of the second-calendar year. By which time first-winter Yellow-legged has undergone a complete body moult and become more like a Herring Gull than a Lesser Black-backed Gull. Figs. 12 and 13 – the same gull videoed on December 20th 1999 and April18th 2000. |
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Fig. 12 1st-winter Yellow-legged Gull, 20th December 1999 © Brian J Small
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Fig. 13 1st-winter Yellow-legged Gull, 18th April 2000 © Brian J Small
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I hope that I will be able to update this article later in the autumn season, in order to expand upon the plumage range of michahellis.
Brian Small September 2000.
Click here to go back to the beginning of this article
Click here to read Brian's article on Caspian Gull identification
Click here to read Brian's article on the Kings Lynn gull
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