POPULATION INDEXES FOR MIGRATORY BIRDS IN THE SCHLESWIG-HOLSTEIN WADDEN SEA FROM 1987 TO 1993

High tide roost counts have been carried out each spring tide at many sites in the Schleswig-Holstein Wadden Sea (Germany) since 1987. Popul ation indices were calculated for 34 species for each year up to autum n 1993. Despite high fluctuations they indicate positive trends for 16 species and negative trends for 2 species during the short period of time considered. A series of mild winters since the beginning of the p roject is discussed as one possible reason for the general increase. A lthough only a part of the Wadden Sea is included in the project yet, the value of spring tide counts in monitoring migratory birds in the W adden Sea is obvious.