SAEIJS HLF & BAPTIST HJM (1976) The occurrence of the Great Crested Grebe Podiceps cristatus on the Grevelingen Lake. LIMOSA 49 (1): 1-8.

Great Crested Grebe Podiceps cristatus After the enclosure of the Grevelingen estuary in the South-West of the Netherlands in 1971, bird censuses were held every 14 days on which an increasing number of Grebes Podiceps cristatus was counted during the months of October until March. The maximum recorded number was 9700 individuals. From October until the end of December the Grebes were distributed all over the lake. In January they started to concentrate in groups. Shortly after that a part of them migrated. After that, until March, the numbersincreased again, but then almost all the birds lived concentrated in one or two big groups. In March almost all the Grebes left the lake in a short time. The number 9700 is a large fraction of the West-European populations involved.

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