title: Interindividual influence on diurnal rhythms of activity in cycling and noncycling populations of the field vole, Microtus agrestis L.
abstract: The effects of interaction among individuals with respect to wheelrunning activity has been investigated in two geographically separated populations of the field vole Microtus agrestis L. In one of them, a northern cyclically varying population, a strictly nocturnal activity pattern is changed into a more or less short term 24 h pattern under conditions of increased contact among individuals. In the other population, south-Swedish, without population cycles, no such effects were observed. This indicates population differences in response to interindividual contact which might be of importance to the known differences in population dynamics.
authors.affiliation: Institute of Genetics, University of Umeå, S-901 87, Umeå, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Nygren