Backgrounds and aims .The first breeding bird atlas of The Netherlands, published in 1979 and for which fieldwork was conducted in 1973-77 (Teixeira 1979), was a milestone in Dutch ornithology. It was not only the first time that the distribution of all breeding bird species was mapped at a national level, but it also stimulated a large number of volunteer birdwatchers to take part in follow-up projects like the year-round atlas in 1978-83 (Atlas van de Nederlandse Vogels; SOVON 1987) or become involved in long-term monitoring projects such as the Broedvogel Monitoring Project (BMP; common breeding bird census). These projects were among the first national ornithological surveys organised by SOVON Vogelonderzoek Nederland (Dutch Centre for Field Ornithology), initially established as a foundation in 1973 to stimulate volunteer field ornithology, but today co-ordinator for national ornithological monitoring projects.