In the high-altitude meadows, rocky slopes, and tundras of North America, Europe, and Asia, colonies of plump, ground-dwelling rodents called marmots thrive in tight-knit social groups. These furry, burrowing animals are famous for their loud, high-pitched calls—used to warn the colony of predators—and their communal lifestyle, which helps them survive the harsh winters and predators of mountain environments. Marmots are part of the squirrel family, but unlike their tree-climbing relatives, they are fully terrestrial, building complex underground burrow systems that serve as homes, food storage, and safety shelters.
Marmots’ burrows are engineering feats. A single burrow system can be up to 30 meters long, with multiple chambers for sleeping, hibernating, storing food (like grass, roots, and flowers), and raising young. The entrance holes are often hidden under rocks or thick vegetation to avoid detection by predators like coyotes, eagles, and foxes. One of the most important chambers is the hibernation den, which is lined with grass and insulated to keep the marmots warm during winter, when temperatures can drop to -30°C. Marmots hibernate for 6-8 months each year, slowing their heart rate from 120 beats per minute to just 3-4 beats per minute and living off fat reserves they build up during summer.
Marmots are highly social animals, living in colonies of 10-20 individuals (though some colonies can be larger). Each colony has a strict hierarchy, with dominant males and females leading the group. One of their most well-known behaviors is “sentry duty”: while most of the colony feeds on grass or grooms each other above ground, one or two marmots stand upright on their hind legs, scanning the area for predators. If a threat is spotted, the sentry lets out a sharp, whistling call, and the entire colony dives into the nearest burrow within seconds. This cooperative sentry system is critical to their survival, as it gives the group more time to escape danger.
During summer—their active season—marmots spend most of their time eating to build up fat for hibernation. They are herbivores, feeding on a variety of plants, and their foraging helps control plant growth and spread seeds, making them important for maintaining mountain meadow ecosystems. Marmot pups are born in spring, blind and hairless, and stay in the burrow for the first few weeks of life. By summer, they start venturing above ground with the colony, learning to forage and recognize predator calls. While most marmot species are not currently threatened, climate change is altering their mountain habitats—warmer winters are shortening their hibernation period, which may affect their fat storage and survival in the long term.
