Baltic and Heuglin's Gull Photo Essay by Chris Gibbins and Paul Baxter - part four
Plate 19. Adult heuglini, Tampere, 23/07/01. Birds presumed to be heuglini were very variable in size, structure and upperpart tone. As with this bird, several were small, delicate and rather fuscus-like. We assessed the upperpart tones of adults using a Kodak grey scale. The grey scale can be used in the field by looking at the bird through your scope with one eye and holding the grey scale so that it is viewable through the other eye; with practice, the bird and the scale appear "together", allowing direct comparison. We validated estimates by comparing our independently derived values. Tones were only assessed in neutral light conditions. This birds was estimated to be a Kodak 11, while others were as pale as 8/9 (fuscus on the trip were estimated to be in the range 17-19; Scottish graellsii are 11-13).
Plate 20. Adult heuglini, Tampere, 23/07/01.
Plate 21. Adult graellsii, Aberdeen, Scotland, July 2001. On current knowledge it is difficult to separate graellsii and intermedius from heuglini. There are "average differences" in some features but their value in identifying lone vagrants is a matter of opinion. Although not the best photograph in the world, the structural similarities between this graellsii and the heuglini in Plate 20 are clear.
Plate 22. Presumed heuglini, (age uncertain), Tampere, 23/07/01. This was a very large, robust individual, similar in size to many of the Herring Gulls present. Its upperparts were Kodak 9/10.
Plate 23. 3cy presumed heuglini, Tampere, 21/07/01. Similar in general appearance to many graellsii/intermedius of the same age (although note the dark eye). This individual was in active moult, with P1-P2 new, P3 regrowing, P4 missing and P5-P10 old.
Plate 24. 2cy heuglini, Tampere, 21/07/01. A very striking, jizzy bird. Scapulars show an admixture of older brown and adult-type grey feathers. The bird is in primary moult: P1 and P2 are new second generation feathers, while P4(approximately) to P10 are first generation (juvenile) feathers.
Plate 25. 2cy heuglini, Tampere, 21/07/01. Same individual as plate 24. This bird was instantly recognisable among the hordes of scavenging gulls. Nonetheless, conveying this distinctiveness in words is not easy.
Concluding remarks
Tampere rubbish dump proved to be a fantastic place to study and photograph gulls. However, watching and photographing them is one thing, fully understanding them is another. Variation in the general appearance and moult of 2cy fuscus in particular was bewildering and on some evenings we left the dump quite exasperated. Whether our experience is enough to call a fuscus (or indeed a heuglini) in Scotland with 100% certainty remains to be seen; a confident claim is likely to require bravado unjustifiable on the basis of current knowledge. Nonetheless, we hope birders continue to search for these fascinating gulls in Britain.
We would like to thank Annika Forsten and Visa Rauste for their help in Finland and instructive discussion of some of the birds pictured here. Thanks also to William Velmala for his hospitality in Turku and Lars Svensson who helped with fuscus sites in Stockholm. Thanks also to Brian Small for useful comments on earlier versions of this article.
All photographs are by CG; anyone wishing to use any of these for publication should contact c.gibbins@abdn.ac.uk.
References.
Buckingham D L, 1998. Variation and occurrence of intermedius Lesser Black-backed Gulls in southern England. British Birds 91: 60-64.
Gruber, D. 1999. Identification of juvenile and immature Baltic Gulls. Dutch Birding, 21, 129-147.
Jonsson, L. 1998 Baltic lesser Black-backed Gull- moult, ageing and identification. Birding World, 11, 295-317.
Rauste, V. 1999. Identification and moult of Baltic Lesser Black-backed Gull Larus (fuscus) fuscus and Siberian Gull L. (fuscus) heuglini. Limicola 13, 105-128 (part 1) and 153-188 (part 2).
Murray, R. 2001. The 1999 Scottish Bird Report, Published by The Scottish Ornithologists Club, June 2001.
Chris Gibbins, Newburgh, Aberdeenshire, Scotland. e-mail c.gibbins@abdn.ac.uk
Paul Baxter, Greater Manchester. e-mail Paul.Baxter@EmersonProcess.com
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