Ardea
Official journal of the Netherlands Ornithologists' Union

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Strann K.B. & Vader W. (1992) The nominate Lesser Black-backed Gull Larus fuscus fuscus, a gull with a tern-like feeding biology, and its recent decrease in northern Norway. ARDEA 80 (1): 133-142
In northern Norway, Larus fuscus fuscus feeds mainly offshore on the wing on pelagic fish and fishery discards. It avoids competition with other large gulls for concentrated stationary food sources such as garbage dumps and fish-factories. It is also inferior to the Herring Gull L. argentatus and the Great Black-backed Gull L. marinus when competing for large food items behind stationary or slow-moving fishing boats. However it is superior in obtaining small items from fast-moving boats. Nominate fuscus is clearly more specialised in its feeding biology than L.f. graellsii and L.f. intermedius. It also shows clear differences in morphology, migration route, moulting cycle, population parameters and population development, and may be specifically different from graellsii and intermedius. During the last decades the breeding population of nominate fuscus in northern Norway has decreased alarmingly. Food shortage is thought to be the main reason for this decrease.


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