Erfahrungen mit verschiedenen Ködermitteln und unterschiedlicher Ausbringungstechnik zur Bekämpfung forstschädlicher Wühlmäuse

On 17 field plots of 0,25 to 1 ha in forest plantations of southern Germany various commercial baits containing zinc phosphide, chlorphacinon and diphenacoum were tested in a pilot study for control of harmful small rodents likeMicrotus agrestis, M. arvalis andClethrionomys glareolus. The baits were dispersed in different concentrations over the ground or alternatively they were put together with a piece of apple in bait stations. The animals in the field plots were trapped by means of live traps, marked and released. The efficacy of the treatments was tested by repeating this procedure in consecutive time intervals and by analysing the fractions of marked and unmarked specimens. In comparision with a disperse distribution of the unprotected baits over the ground surface better results and a more lasting success could be mostly obtained with only 9 earthenware pipes distributed over one hectare and filled with a small amount of baits together with a piece of apple. The advantages and disadvantages of the bait station technique are discussed. It is assumed that the efficiency of the bait station technique can be improved by means of attractants and pheromones.