FEMALE VOLES DISCRIMINATE MALES OVER-MARKS AND PREFER TOP-SCENT MALES

Scent over-marking is a common form of competitive advertisement among many species of mammals. Recent observations in golden hamsters, Meso cricetus auratus, have suggested that individuals have specialized mec hanisms for interpretation of and response to such over-marks. In this study, we examined whether meadow voles, Microtus pennsylvanicus, hav e similar abilities. Female voles were first exposed to anogenital sce nt marks of two males and were then tested in a Y-maze for their prefe rences for whole-body odours of these two males. Experiments were run using a variety of configurations of scent marks during the exposure p hase, but all experiments yielded consistent results. If the scent mar ks of the two males overlapped, females later preferred the whole-body odours of the male whose scent was on top; if the two scent marks did not overlap, females showed no preference. Females also preferred odo urs of familiar males over novel males, and preferred both top-scent a nd bottom-scent males over novel males. The results suggest that femal e voles can tell which individual's scent is on top in an over-mark an d that they prefer this top-scent male, even though they know that bot h males' scents were present during the exposure phase. We suggest tha t these odour preferences reflect mate preferences and discuss possibl e reasons why females might prefer top-scent males. (C) 1997 The Assoc iation for the Study of Animal Behaviour.