The Cormorant has been colonising several new, marine breeding sites in The Netherlands in recent years. The development of one of these new colonies, at Meyendel, is described. Summering birds were first seen in 1985, courtship and transport of nest material was first noted in 1986, breeding was recorded once in 1988, but still no eggs or young were seen. The next breeding attempt was in 1991 and numbers subsequently increased (until 72 pairs in 1995; Table 1). Feeding occurs probably largely at sea, but fresh water lakes are also visited.