Identification of 2cy Heuglin's Gulls in W Europe

Introduction. Heuglin's Gull Larus heuglini is one of the most enigmatic large gulls occurring in Europe. It was not until the late 1990s that several papers were published on its identification. These raised the awareness of the appearance of heuglini and its occurrence outside of what was perceived to be its normal range (heuglini breeds Siberia and winters in the Middle East, E Africa and parts of S Asia). However, unlike Caspian Gull L cachinnans, a species for which much progress on identification was made in just a few years, Heuglin's Gull remains something of a mystery. For the aims of this web site, an explanation as to why only second calender-year (2cy) Heuglin's Gulls are treated here, a basic introduction to moult and a list of acknowledgements, please continue to the full introduction. If you are interested in a summary of the material covered on these web pages, please move directly to the conclusion.

Recent changes: added an overview page with all ringed 2cy graellsii and intermedius on 25 July 2009. Please have a look if you can contribute with pictures!

Authors. Ruud Altenburg, Chris Gibbins, Hannu Koskinen, Bert-Jan Luijendijk, Mars Muusse, Theo Muusse and Visa Rauste. When appropriate, please cite as: Altenburg, R.G.M., C.N. Gibbins, H. Koskinen, B.-J. Luijendijk, M.J.M. Muusse, T.O.V. Muusse and V. Rauste. 2007. Identification of 2cy Heuglin's Gulls in W Europe.

2cy Lesser Black-backed Gulls L f graellsii 2cy Lesser Black-backed Gulls L f graellsii. This subspecies breeds in Iceland, Great-Britain and from the Netherlands south to the Iberian Peninsula. It is often thought to be rather uniform in its appearance, being rather robust and with a limited moult on the wintering grounds. Our small sample of ringed birds indicates that this assumption is basically correct, but also that a small number of less typical birds may resemble Heuglin's Gull.
2cy Lesser Black-backed Gulls L f intermedius 2cy Lesser Black-backed Gulls L f intermedius. The scientific name of this taxon is appropriate, as in many aspects intermedius is intermediate between graellsii and fuscus. This taxon breeds from N Norway east to W Sweden and south to Germany and Denmark. Intuitively, we might expect that is the main culprit for confusion with heuglini, but thus far our sample of ringed birds suggests that only a few may cause problems.
2cy Baltic Gulls L f fuscus 2cy Baltic Gulls L f fuscus. Baltic Gull breeds in N Norway (in colonies together with intermedius), E Sweden and Finland, east to N Russia. Some birds showing reduced moult are impossible to separate from intermedius and paler individuals are, on current knowledge, practically inseparable from Heuglin's Gull.
Heuglin's Gull - Larus heuglini 2cy Heuglin's Gulls L heuglini in Russia. Heuglin's Gull breeds in the tundra in N Russia in isolated pairs or small colonies. This seriously impairs the possibilities of a wide-scale ringing program and consequently it is difficult to obtain a "pure" sample of heuglini for study. The pictures in this section were made by Visa Rauste on the dump of Syktyvkar, Russia (61.40 N, 50.48 E), where western Lesser Black-backed Gulls should not occur.
Presumed 2cy Heuglin's Gulls in Finland Presumed 2cy Heuglin's Gulls in Finland. All heuglini photographed in Finland should be considered "presumed Heuglin's Gulls". Even if it is unlikely, it is impossible to exclude the possibility that some of the Finnish birds presented on this web site are of western origin. This wide selection of photographs shows birds that are very different to those observed in W Europe but similar to those photographed in Russia.
Candidate Heuglin's Gulls in W Europe Candidate Heuglin's Gulls in W Europe. Examples of birds that possibly are beyond the variation known to occur in graellsii/intermedius Lesser Black-backed Gulls. The authors very much welcome pictures of ringed birds resembling any individuals in this section.