The Siberian chipmunk is a small rodent and the only chipmunk species found outside of North America. Its native range spans northern Asia, but it was introduced to Europe through the pet trade starting in the 1960s. This introduction has led to the establishment of wild populations in several European countries.
Physical Characteristics and Habitat
The Siberian chipmunk (Eutamias sibiricus) measures 18 to 25 cm in total length, with its tail making up about a third of that. Its body weight fluctuates with the seasons, ranging from 50 to 150 grams. The fur is yellowish-brown on its back and white on the belly, marked by five dark and four light stripes running lengthwise from its shoulders toward its rump.
This chipmunk’s native habitat extends across northern Asia, from central Russia eastward to China, Korea, and the island of Hokkaido in Japan. It thrives in coniferous forests, taiga, and areas with rocky outcrops that provide cover. As an adaptable species, it also colonizes woodland edges and suburban areas.
Behavior and Diet
Active during the day, Siberian chipmunks are solitary animals that spend their time foraging and preparing for winter. They construct elaborate burrows up to 2.5 meters long and 1.5 meters deep. These burrows contain multiple chambers designated for different purposes, including a nest, separate storage areas for food, and a chamber for waste.
Their omnivorous diet consists of pine seeds, grains, fruits, fungi, and various tree seeds. They supplement this with insects, mollusks, and occasionally small birds or reptiles. To transport food, they use large cheek pouches that can stretch to three times the size of their head, allowing them to store 3 to 4 kilograms of food for the winter.
Siberian chipmunks enter a state of torpor during the winter rather than true hibernation. They spend the cold months sleeping in their nests but wake periodically. During these brief periods, they consume food from their caches before returning to rest.
Role as an Invasive Species
In Europe, escaped or released individuals have established wild populations, leading to the chipmunk’s classification as an invasive species. These populations create ecological imbalances by competing with native small mammals, such as red squirrels and wood mice, for food and habitat resources.
These chipmunks are also a vector for disease-carrying ticks. They can be heavily infested with ticks that transmit Borrelia burgdorferi, the bacterium causing Lyme disease. Research in a Parisian forest found that chipmunks contributed more to the density of infected ticks than native rodents, increasing the risk of Lyme disease transmission to humans.
Siberian Chipmunks as Pets
Once popular in the pet trade, ownership of Siberian chipmunks is now heavily restricted. In 2016, the European Union listed it as an Invasive Alien Species of Union Concern. This designation makes it illegal to import, breed, sell, or release the animal within the EU. Owners who had them before the ban may keep them, provided the animals are kept securely and prevented from breeding.
Keeping these animals is challenging as they are not domesticated and retain wild instincts. Although they can be active and engaging, they are wary of handling and may bite, especially as adults. Their complex needs require large, secure enclosures that allow for natural behaviors like climbing and digging, which a standard cage cannot provide.