Effects of ecological factors on the diurnal activity rhythm of Yakutian black-capped marmots (Marmota camtschatica bungei) in the Arctic

It is established that the activity of marmots (the genus Marmota) on the surface is timed to the daylight period. In the Arctic, under conditions of continuous illumination (the polar day), the diurnal rhythm of black-capped marmots Mamota camtschatica bungei on the surface has a daylight pattern. The main external regulator of the diurnal rhythm is the altitude of the sun above the horizon. In the cold period, however, the effect of air temperature on animal activity becomes stronger.