OUWENEEL GL (1983) Short contributions:The occurrence of Wigeon Anas penelope in the northern Delta area. LIMOSA 56 (1): 20-20.

The delta in the southwestern part of the Netherlands is one of the most important haunts of Wigeon Anas penelope in Europe. Every winter about 30 000 Wigeon occur; 62 000 have been counted at most. Most of the Wigeons stay in the northern part of the delta. Nowadays the Grevelingen is the most important site in this area. The increase of Wigeon in the Grevelingen after its closure from the sea coincides with the expansion of eelgrass Zostera marina. The difference between autumn and spring numbers is probably caused by lack of inundated grassland in spring. Eurasian Wigeon Anas penelope

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