The active season is relatively consistent among years, although tracks have been seen as early as April 17th, and animals have been seen aboveground as late as October 18th. Yearlings generally expand their movements but almost inevitably return to hibernate with their mother a second time. Dispersal records are scarce, but it appears likely that M. vancouverensis generally disperse when reach the age of 2 or 3 years. D ispersing marmots can make impressive movements. Ear-tagged marmots moved distances up to 10 km.
Individual colonies suffer extinctions so that at any time some patches are unoccupied.
Causes of mortality U nsuccessful hibernation and predation are the largest causes of mortality, especially for pups. R adio-telemetry provides conclusive evidence that predators exact a toll. Numbers of individuals in each sample are shown. M ost Vancouver Island marmots apparently die during hibernation, when physiological resources are weakest. D isease may also play an important role.