The effect of social odour context on the amount of time male meadow voles, Microtus pennsylvanicus, self-groom

Communicational behaviours by individuals provide information for not only the intended target(s) of the signal but any non-target individual(s) that may be nearby. For terrestrial mammals a major form of communication and social information is through odours via scent marking and self-grooming. Self-grooming is a ubiquitous behaviour in mammals with the function thought to primarily be centred on personal care. But it has been found in rodents that self-grooming will occur in the presence of social odours thus potentially serving a communicative role. For example, male meadow voles (Microtus pennsylvanicus) self-groom in the presence of a female conspecific odour but not a male conspecific odour. Most studies examining self-grooming as a form of olfactory communication have used single odour donors but in a natural environment individuals will come across complex social odour situations. Therefore, we examined how male meadow voles respond to complex social odours with regards to their self-grooming behaviour. We tested the hypothesis that self-grooming can act as a form of olfactory communication and that male meadow voles will control this behaviour measured by differences in self-grooming rates based on social contexts. Male meadow voles did not show differences in the amount of time spent self-grooming to social odours that contained a female and varying number of rival males (0, 1, 3, or 5) or if the social odour contained an acquainted or novel male. Male meadow voles did self-groom more to a social odour that contained a female and a younger male compared to when the social odour contained a female and older male. Male meadow voles appear to adjust their self-grooming behaviour based on the context of the social information. This may be a strategy that can maximize that individual’s fitness by adjusting how much information is provided to potential rivals and mates.