On some aspects of physiologico-biochemical processes determining the variability of the fur coloration in European

The increase of red tint along with whitening of the general fur coloring under decreasing of average daily temperature has been shown on a series of Bank Voles, captured in Tver region. The phenomenon appears to be connected with the temperature-dependent activity of tyrosinase as well as with distribution of eu- and phaeomelanin in the hair of the vole. The ambiguity in the appearance of fur coloring characters dependant on external and internal causes is demonstrated.