Acoustic signal characters in interspecific hybrids of bank and red-backed voles

It has been found that distress signals of bank and northern red-backed voles and their hybrids do not differ in qualitative characters, but the modes of the acoustic signal parameters in many cases differ in the hybrids depending on their origin and can be correlated with the inheritance of some morphological characters that are typical for the species. It is noted that the distress-signal frequencies (quartiles) differ significantly in the first-generation hybrids of various origin and their characteristics are closer to those of the paternal parent species. It has been found that the inheritance of the frequency characteristics by the second-generation hybrids does not have a well-pronounced regularity.