INFLUENCE OF PHOTOPERIOD AND TEMPERATURE ON MOLTING PROCESSES IN MICROTUS-BRANDTI (RADDE, 1861)

Voles were kept under different environmental conditions (light and te mperature regime). The duration of seasonal moults is closely connecte d with temperature changes. Nevertheless seasonal hair changes seem to be fixed endogeneously because they also occur under constant light a nd temperature conditions. However, the endogenous rhythm can be force d by varying environmental conditions. An intermediate moult was obser ved in Microtus brandti between the two winter furs. This could be ind uced by shortening day length. An increase in hair density is a result of short day length and low temperatures.