Ethological isolation between local populations of house mice (Mus musculus) based on olfaction

Some rodent populations are composed of demes which remain reproductively isolated within the major population. Territoriality has been advanced as a possible isolating mechanism. This research investigated the possible role of olfaction in the isolation of feral house mouse (Mus musculus) demes. When given a choice, male and female mice spent more time with the air-transported odours of members of their own deme than with those of neighbouring deme members. Tests with a fresh-air control showed that mice avoided the odours of members of an adjacent deme. In addition, more time was spent with urine and faeces odours of members of a mouse's own group than with those of the members of an adjacent deme. The production and detection of odorous substances may contribute to the autonomy and relative reproductive isolation of some local populations of mice.