Rudi Drent in Canada, October 1984.

With the death of Rudi Drent on 9 September 2008, the Netherlands Ornithologists' Union (NOU) lost a long-serving chairman (1975–2000), preceded only by J. Biittikofer (1909–24), L.F. de Beaufort (1924–56), W.H. Bierman (1957–66), K. Waldeck Jr. (1966–71) and H. Klomp (1971–75). His stint of chairmanship took place during a rapidly branching ornithological landscape in The Netherlands. Starting in the 1960s, an increasing number of birdwatchers set themselves new tasks, and at present the number of local and regional Dutch avifaunas published in book format takes at least two metres of bookshelves. The number of bird clubs exploded from about 75 around 1970 to some 225 in 1993. Against this background, in 1971, the NOU took the first steps of the creation of what later would become SOVON (Dutch Centre for Field Ornithology), then under chairmanship of Herman Klomp who also became the first chair-Rudi Drent Canada, October 1984. man of SOVON after its founding in 1973. To bring together, and instruct, the thousands of amateur birdwatchers in The Netherlands was thought to be beyond the capacity of the NOU, and called for a separate organisation specifically targeted at standardised monitoring and atlas surveys on a country-wide scale. And so it happened.

Rather than watching birds and the birding community from an ivory tower, both Herman Klomp and Rudi Drent were excellent and active field ornithologists themselves, deeply interested in long-term research and well aware of the potential and value of long time series run by volunteers. Both were convinced, however, that, for such schemes to be meaningful, strict scientific standards should be applied. Herman Klomp was quite straightforward in his idea of the position of birders in this setting: study targets should be formulated by scientists, fieldwork should be performed by birders according to standards provided by scientists, and analyses of the results were again the domain of scientists. Not surprisingly, his outspoken ideas sometimes resulted in volatile meetings, some of which I vividly remember. Rudi was of much the same opinion, but his more diplomatic approach appeased even the most outspoken adversaries. His talent of synthesising large amounts of information from various sources stood in good stead when it came to presiding meetings. Sitting in the front row, making notes of the presentations, he would often come up with a cohesive view and new questions at the end of the day. Innumerous students have profited from his insight in the complexity of nature's laboratory, as materialised in the Liber amicorum published to commemorate his stint of professorship in Animal Ecology at the University of Groningen. The smell of fieldwork permeates the pages of this book. To study live organisms in their natural setting was regarded by Rudi as a great privilege. Tramping the salt marshes of Dollard, or cruising the coastline of Lauwersmeer with his boat “Ilse” during the monthly waterbird counts, were a joy and a necessity of life at the same time. Ecological concepts can be formulated behind a desk, but they were actually happening out there, often twisting in unforeseen ways or haloed in beauty. And what better place to digest information and think up something new?

After his retirement as an animal ecologist in the Centre for Ecological and Evolutionary Studies at the University of Groningen, Rudi continued to give freely of his time to whomever was involved in the study of birds. Again, without making a distinction between professionals and non-professionals. His translation of De onvrije natuur, the Dutch predecessor of Seeking nature's limits, solved the predicament of telling ‘his’ story of 25 years of ecological research, perhaps in the spirit of David Lack (1965) who did so “for those with a general interest in natural history rather than for professional specialists”. Lack also expressed another dilemma, in today's world of ‘fast science’ even more felt than half a century ago: “Professional scientists are often blamed for restricting their findings to technical papers in learned journals, to which they may reply that time spent in writing for a wider group of readers is time lost from research which is their main job.” Rudi solved this dilemma in the same manner as David Lack, whose thought-provoking work he immensely admired, namely by bringing together a series of papers on animal ecology written for a general public. Both scientists confessed that studying birds was a joy in itself, expressed by Lack that he always, paid or unpaid, had studied birds “as an amateur”. In other words: out of love for birds.

Comments by Joost Tinbergen and Leo Zwarts are greatly appreciated. A full obituary of Rudi Drent will appear in the next issue of Ardea.