Gestation lasts 30-32 days and young are born in a burrow padded with grass. The litter size is usually 4-5 offspring. Behavior Olympic marmots are highly social and may live in groups of over a dozen animals. These groups usually include an adult male, two adult females, yearling offspring, and newborn offspring. Gregarious bonds are made between individuals in a family.
Olympic marmots identify each other by touching noses and smelling of cheeks.
This behavior, along with grooming, establishes the standing of each individual in the family. Little contact occurs with a neighboring group, though a border may be shared. Olympic marmots are diurnal and terrestrial animals. During the morning and afternoon on summer days, they feed and spend time sunbathing on rocks. In the evening, they return to their burrows.