A quantitative description of the copulatory behaviour of meadow voles ( Microtus pennsylvanicus)

Abstract

Nine pairs of meadow voles, Microtus pennsylvanicus, each received five laboratory tests of copulatory behaviour. Each test was continued until attainment of a satiety criterion of 30 min with no intromissions. Tests of a possible Coolidge effect were conducted on three tests of each pair. The copulatory pattern was characterized by intra-vaginal thrusting, no lock, and multiple ejaculations. Whereas the first ejaculation always was preceded by multiple intromissions, later ejaculations typically required just a single insertion. Mean ejaculation frequency was 5·9. A Coolidge effect was demonstrated as ‘satiated’ males resumed copulation upon introduction of a new female.