Mislukt broedgeval van de Zwarte Wouw Milvus migrans langs de IJssel bij Doesburg in 2000

After earlier breeding attempts in The Netherlands in 1984 (failed during egg stage, De Wieden) and 1996 (1 fledgling, elsewhere along the IJssel), a third breeding case was recorded in 2000 in a partly flooded woodlot (10 ha) along the river IJssel in the eastern Netherlands (Photo 1). The nest was situated at a height of 16 m in a Salix alba, at 140 m distance of a small Cormorant Phalacrocorax carbo colony. The same woodlot also held active nests of Goshawk Accipiter gentilis and Common Buzzard Buteo buteo (Appendix 1), The old nest had been built by a Common Buzzard and twigs and plastic were added by the Black Kite pair in April. An incubating bird, probably the female, was seen on 3 May. Although a single bird was still present on 7 May (not seen on the nest), the nest was presumably already deserted by then. Throughout May and June, a single moulting bird (thought to have been the female) was seen in the vicinity of the nest site, up to 4 km away (but mostly within 2 km). The last observation dates from 6 July. The nest partly collapsed during a gale in the night of 28/29 May, after which egg shell remains were found underneath (Photo 2). The reason of nest failure remained a mystery. The disappearance of the male may have been crucial, but the storm in late May would have aborted the nesting attempt anyway (lopsided position of nest because of gale).