Ornis Hungarica. vol.12-13. (2003) p.183-191.
Swallow censuses in Northwest Germany (1986,1991 and 1996)
Starting in 1961, from 50-100 villages and settlements in the industrial area of Hannover- Braunschweig (centred on Peine) have been checked at 5-year intervals to count the nesting population of House Martin Delichon urbica and Barn Swallow Hirundo rustica, the method being a direct nest count. The hitherto stable Barn Swallow populations declined in the late 1980s whereas the steady increase of House Martin ceased because of new developments following German reunification in 1989. The numerical results are presented. Decrease and increase are analysed in regard to landscape (hillside - moraine - loess zones), size and economic status of the settlements (between 50-50 000 inhabitants, traditional rural - highly industrialised areas).