SCHOUTEN C (1985) Short contributions: Five years of counting Black Terns Chlidonias niger in the IJsselmeer area. LIMOSA 58 (3): 124-124.

Black Tern Chlidonias niger During 1980 - 1984, counts of Black Terns were made in the IJsselmeer area. The birds were counted during their flights to the three roosts. In 1983, a very large total of 108 300 Black Terns was recorded. It is estimated that 150-200 000 Black Terns are migrating through the IJsselmeer area each year. The percentage of first year birds is 10-15 in mid August and 20-25 in September. Since the NW. European population is small, almost all birds will probably come from the USSR

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