Beached Bird Surveys, Mar – May 1991
Sula , Volume 5 - Issue 2 p. 76- 77
Counts were received covering 183, 54, and 35 km respectively. Species composition in March was much the same as in February (see Sula 5(1)), with many waterfowl and waders. New mass standings of seabirds and oil, like in November 1990 and in January 1991, did not occur. Divers were scarcely found, a fair number of dead grebes were the result of the cold weather in February. Of the true seabirds, Fulmars were remarkably rare till May (a wing moulting dark phase bird was picked up at Texel on 19th May; CJC), one peculiar Gannet stranding was reported (see below), Larus-gulls and Kittiwake were not very numerous, Guillemots stranded in numbers in March, but very few were found in April and May, Razorbills remained relatively scarce. The beached bird surveys of this spring are shadowed by mass mortality of Eiders, particularly in the western Wadden Sea and along the coast of Noord-Holland. Walking blindfolded across Texel, one can easily smell whether or not beach or Wadden Sea dike are nearby. Acute food shortage is the main reason for the mortality, and wintering numbers in the Wadden Sea this last winter were considerably smaller than usual, with an atypical distribution (sec Swennen 1991). An exodus of Eiders out of the Wadden Sea has occurred and many starving birds could be observed along the mainland coast of Holland and in the Delta area. Also, many Eiders appear to be infected with the parasite worm Polymorphus botulis (KD). The reason for the food-shortage is probably mainly because of intensified fisheries for Cockle Cerastoderma edule and Mussel Mytilus edulis in the Wadden Sea (Swennen 1991).
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