In 2000 fewer water and marsh birds nested in the Netherlands than in preceding years. The high bird balance values in 1998 and 1999 were probably caused by the high levels of rainfall in the preceding winters, giving birds more opportunities to nest.
Generally speaking, populations of water birds (such as the teal and the moorhen) have been increasing in recent years. The numbers of marsh birds on the other hand have been more irregular. The populations of birds which depend on wet marshes to nest, (such as the bittern and the great reed warbler) have declined, in spite of relatively favourable water levels, while species which benefit from rough reed-land (bluethroat and sedge warbler) are thriving. The kingfisher too had a better year in 2000: this river bird is very vulnerable in frost periods and has therefore been able to benefit from the recent very mild winters.
Water and marsh birds include 49 species. Since 1990 the populations of most of these species have retained their level or increased. Only one in ten species is declining.
Calijn Plate and Arend van Dijk (SOVON)