Heuglin's Gull (L. heuglini / antelius)(last update: |
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Heuglini adult, January 12 2005, Oman: Barka.Picture by Osao & Michiaki Ujihara: http://www23.tok2.com/home/jgull/OmanGulls/ You can also mail: ujihara"add"mpd.biglobe.ne.jp In the Arabian Gulf, four species of large gulls can be found commonly. Heuglini, and fuscus are breeding species from the northern tundra. Cachinnans and barabensis are steppe breeders. The breeding location may give criteria for identification of single individuals. Breeding on either southern steppe or northern tundra has some major consequences: a: the breeding season starts much earlier on the steppe, hence can be finished much earlier. b: northern breedres must migrate over much longer distances and this has consequences for their moult strategy and timing. c: steppe breeders spend much more time under tropical climate conditions, while feathers of the tundra breeders are less likely to be exposed to such conditions, and this may have effects on bleaching and wear of e.g. primaries. The image below shows an adult heuglini, and shows some characteristics features: - Fierce facial expression, accetuated by the dark smudge in front of the eye. Expression not unlike European Herring Gull. - Upper parts rather dark grey; much darker than in cachinnans and barabensis; but slightly paler than fuscus. - Late moult timing of the primaries. In this individual, all old outer primaries have been shed, but only P8 is full grown. P9 & P10 still growing. - Visible primaries and the primary tips look brand new, recently moulted. - Structurally, the head shape is angular in this individual. As can be seen in the pictures, some coverts have a brown hue while some look rather grey-brown. Probably these feathers belong to different generations. In the Netherlands, we may see such a brown cast over the wing coverts as well; as it seems, more often in old coverts in the type intermedius - Most reliable feature for heuglini might be the bill, which can look very cachinnans-like: slender, without a clear gonydeal angle, pale yellow. The gonydeal spot is often rather orange-red, not as deep coral red as in western LBBG taxa. This, together with the sloped head makes the bill look longer than in most intermedius LBBG. - Another cachinnans-like feature is the winter head pattern. Winter streaking seems to be concentrated in the lower neck and may run as a band downwards, it sometimes continues on the side-neck, creating a collar of fine streaks, as can be seen in (sub-adult early winter) cachinnans.
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