In September 1970, I visited the Muenster sewage farm for the first time – I can still remember the evening well.  Michael Harengerd, Werner Prünte, Michael Speckmann and I met near the “ringing centre” – an old green site trailer.  We caught passerines, and I was hooked from that day!  I spent much of my spare time during my student days at the sewage farm, where I learned the scientific techniques of handling, measuring and ringing the waders and passerines we caught there.

As a biology and geography teacher, my work mirrored my natural interests.  During my free time I continued the study of stonechats that I had begun in 1976j with Friedrich Pfeifer in the Heubach lowland near Duelmen.  Our aim was to learn all we could about this species.  Bioacoustics were an important part of this, as were breeding biology, phenology, population development, moult and nutrition.

Towards the end of the 1970s and the beginning of the 80s, there was a significant decline in the stonechat population.  This led us to adopt a second study area which had a stable stonechat population: the Dueffel lowland in the Lower Rhine area.  We also decided to focus out studies on a second species – the yellow wagtail.  At the beginning of the 1990s, we began a joint project with Eberhard Gwinner, and were later joined by Barbara Helm and teams from the Max Planck Institute and set up a third study area at Geisterbusch in the Wahner Heide near Cologne.  I studied stonechats there for ten years.

The ligature method for diet analysis was fascinating, but because stonechats normally feed their nestlings with single large prey items, was rather unproductive for this species.  Greig-Smith and Quicke’s paper on the diet of nestling stonechats in Britain, published in 1983, made me keen to try faecal analysis.  After training intensively in this method, I found my ornithological niche.  Stonechats were a good species to learn on because they consume a lot of arthropods, whose remains are easy to identify in droppings.  Driven by my interest, I observed, collected and caught in the field everything I could that added to my knowledge of the species.  In this way I built up a broad reference collection of food remains that I could use for comparison with those found in faecal samples.

Although I am still fascinated with stonechats, dietary analysis became an important part of my work.  I have now analysed the diets of over 50 passerine species from Europe, Japan, Kenya, Panama and Papua New Guinea.  I have also analysed stomach contents and faeces of wood mouse, common vole and rabbit.

Even as a little boy, I kept pigeons, budgerigars and canaries; as a teenager I worked at the Borkener bird park.  I raised by hand many nestlings which were brought to the park, and nursed injured birds of prey and owls back to health and released back to the wild.  As I had the chance to work with the Max Planck Institute I enjoyed taking on birds there and was then able to observe and to breed my beloved stonechats in aviaries there.  Joining with the Vogelwarte Radolfzell and Bernd Leisler’s team from the Max Planck Institute gave me the chance to take care of some more wild bird species such as marsh, reed, sedge, aquatic and moustached warblers (first offspring in captivity in the world).  Today I mainly breed wild canaries.