Divergence of the olfactory signals in subspecies of the house mouse Mus musculus

We used two methods to study the responses of representatives of three subspecies (Mus musculus musculus, M. m. wagneri, M. m. gansuensis) to the olfactory signals of con- and heterospecific individuals: (1) paired presentation of odor sources; and (2) modification of the “habituation” method—“habituation generalization.” To confirm the data obtained with these methods and to interpret the results, samples of mouse urine were presented to humans, who were used as odor detectors. Our results (from experiments with both mice and humans) have shown that wagneri urine odor different from the urine of the other two subspecies, musculus and gansuensis. Differences in the olfactory signals of the subspecies may be the initial stage of reproductive isolation of these subspecies.