Broedsucces en broedassociatie van Velduilen Asio flammeus op Griend

After a series of years (1992, 1994-96) with one single breeding pair of Short-eared Owls Asio flammeus, in 1997, two pairs nested on the island of Griend in the Dutch Wadden Sea. The early pair fledged two chicks, while the late pair had no fledglings. So, as in other years, early pairs had a higher breeding success than late pairs. Pairs were most successful when the hatching period coincided with the spring migration peak of Dunlins Calidris alpina, which in those cases made up more than 50% of the diet of chicks. On Griend, Eiders Somateria mollissima, Mallards Anas platyrhynchos and Common Shelducks Tadorna tadorna clearly form breeding associations with Short-eared Owls. The density of duck nests in the direct vicinity of nests of Short-eared Owls was about three times as high as in other parts of the dike with the same breeding habitat.