Multimodal Oestrus Advertisement in a Small Nocturnal Prosimian, Microcebus murinus

Abstract

Females of many simian primates have evolved distinct signals to advertise their oestrus. Until recently little was known about oestrus advertisement in prosimians. In this paper, we present data on the activity pattern, olfactory and vocal behaviour of female grey mouse lemurs in relation to their reproductive state. Phases of the oestrus cycle were determined according to plasma progesterone levels and changes in vaginal morphology. Females showed significantly increased locomotor activity, scent marking behaviour and changes in self-grooming activity only on the day of oestrus. Furthermore, they uttered a call with a complex acoustic structure which is not heard during other reproductive phases, the oestrus advertisement trill call. Therefore, in mouse lemurs, a combination of olfactory and acoustical signals can serve as multimodal oestrus advertisement.