De cyclus van de veldmuis Microtus arvalis

The cycle of common voles is being monitored in Drenthe since late 1986, by analysing the contents of pellets of Long-eared Owls. The population low of 1994 was extended into 1995 (also visible in a high proportion of birds in the Long-eared Owl’s diet). A low in the cycle has a marked impact on breeding success of vole-eaters.