Mice respond differently to urine and its major volatile constituents from male and female ferrets.

Our previous chemical investigation showed that the concentrations of urinary volatiles from males were much higher than those from females in the ferret (Mustela furo). The current study was designed to examine the behavioral significance and ecological relevance of this difference for one of the main prey of the ferret, the house mouse (Mus musculus). Our data showed that male mice displayed no difference in their response to raw male and female ferret urine. However, they showed significantly less response to female mouse urine mixed with ferret urine than to pure female mouse urine, and to female mouse urine mixed with male ferret urine than to female mouse urine mixed with female ferret urine. Furthermore, high levels of the three major volatiles (quinoline, 2,5-dimethylpyrazine, and 4-hepatanone) in male ferret urine were as effective as raw male ferret urine was in inhibiting the response of male mice. We discuss the ecological and behavioral significance of these findings in terms of chemical mimicry and cognitive feature extraction of predator odors in mice.