1994 0-7734-4050-X During the years 1987-1993, an intensive scientific study was conducted in a brookside meadow on the southwestern edge of Osnabrück, Germany, as part of the Hörne amphibian protection and research project. The objective of this paper is to describe the development of four common toad Bufo bufo populations. The influences of various migration obstacles and predators upon migratory behavior were quantified. The objects of investigation were two railway lines, a brook, agricultural acreage, roads and a built-up area, as well as the influence of predation by rats Rattus norvegicus. The dynamics of time and distance were also studied. In German.