Table of Contents >>
Introduction | Plates 1-21 | Acknowledgements
| 22-23. Bird E. Adult presumed hybrid, Zeebrugge, May 2002 (©Peter Adriaens). Legs are greenish-yellow. In photo 23, the long call is shown, with head thrown back at about 90°, similar to Yellow-legged and Lesser Black-backed Gull. In argenteus Herring Gull, the throw-back usually stops at 80°. |
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| 24-25. Bird E. Zeebrugge, May 2002 (©Peter Adriaens). Primary pattern similar to Yellow-legged Gull, but the tongue of p9 looks slightly longer than in the average adult of this species. The black band on p5 is quite thin. Primary moult has not started yet. |
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| 26-28. Bird F. Adult presumed hybrid, Zeebrugge, May 2002 (©Peter Adriaens). Record shots only. This bird has no or very little black on p5. Note also the very large white mirror on p10, while there is no mirror on p9. |
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| 29. Bird G. Adult presumed hybrid, Zeebrugge, 6 April 2003 (©Koen Verbanck). Paired with a fourth summer Herring Gull. Note the broader white scapular crescent, and broad white trailing edge to the secondaries. |
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| 30-31. Bird G. Zeebrugge, April - May 2003 (©Peter Adriaens). Legs are only dull pinkish-yellow. The red gonys spot appears to bleed onto the upper mandible. |
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| 32-33. Bird G. in flight, Zeebrugge, May & April 2003 (©Peter Adriaens). The black band on p5 is thin, and broken at the shaft. The pale tongue on p9 is slightly longer than on average in Yellow-legged Gull. |
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| 34-35. Bird H. Adult presumed hybrid, Zeebrugge, May 2003 (©Peter Adriaens). Another bird with little or no black on p5, as can be seen in photo 35. The legs are slightly paler yellow than in nearby Lesser Black-backed Gulls. |
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| 36. Bird H. Zeebrugge, May 2003 (©Peter Adriaens). The white mirror on p10 is quite large, and there is no black between the mirror and the tip. |
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| 37-38. Bird I. Adult presumed hybrid, Zeebrugge, May 2003 (©Peter Adriaens). Some feathers are missing around the eye, exposing the rather pale, reddish-orange eyering. |
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| 39-40. Bird I. in flight. Zeebrugge, May 2003 (©Peter Adriaens). The primary pattern is similar to Yellow-legged Gull, though in that species the tongues on p8-9 are slightly shorter on average, creating a more solid black 'triangle' on the underwing in typical birds. |
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| 41. Mixed pair Yellow-legged Gull (background) x Herring Gull, Zeebrugge, 28 July 2002 (©Koen Verbanck). Note broad, heavy head, thick bill and thin white tertial and scapular crescents of the Yellow-legged Gull. |
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| 42-43. Juvenile hybrid Yellow-legged x Herring Gull, Zeebrugge, 28 July 2002 (©Koen Verbanck). The offspring of the pair shown in photo 41 (above). Accompanied by Yellow-legged Gull (one of the parents) in photo 42. The young bird looks very much like a juvenile Yellow-legged Gull, except for its extensively pale bill-base (at least on the upper mandible). |
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| 44. Bird J. first summer hybrid Yellow-legged x Herring Gull, Oostende, 3 June 1994 (©Roland François). Colour-ringed (green, CM5) as a pullus at Rotterdam, The Netherlands, on 8 June 1993. Really similar to Herring Gull, but its moult is slightly more advanced: p6 has been shed, and a number of adult-grey scapulars have grown in already. |
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| 45-46. Bird J. now adult, Oostende, 22 September 1999 (©Roland François). As an adult, this bird bears a slight resemblance to Yellow-legged Gull of the race 'atlantis', but with more pinkish feet and legs, and slightly paler upperparts. Moult stage: p1-6 are new, p7-9 are missing or growing, and p10 is old. Compare with photo 3. |
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Table of Contents >>
Introduction | Plates 1-21 | Acknowledgements
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