About Marmota baibacina Kastschenko, 1899
Gray marmots (Marmota baibacina Kastschenko, 1899) are one of the largest marmot species native to the Palearctic. They typically weigh between 4 and 6.5 kg (9 to 14.5 pounds), with some individuals reaching nearly 8 kg (18 pounds) just before hibernation. Their body size varies based on the time of year relative to hibernation, as well as latitude and elevation; overall, body size increases at higher latitude and elevation, and decreases at lower latitude and elevation. Gray marmots can lose up to 30% of their total body mass during long seasonal hibernation. Their bodies are short and stocky, with strong limbs and short tails. Total body length, which includes the 13 to 15 centimetre (5 to 6 inch) tail, ranges from about 60 to 80 cm (25 to 30 inches). Their forefeet have 4 digits with strong claws suited for digging, while their hindfeet have 5 digits. Their dorsal (back) fur ranges from beige to tan, with brown to black hairs or hair tips blended throughout that gives the coat an overall gray appearance. Their ventral (belly) fur is a more orange-reddish brown. Their tail matches the body coloration for most of its length, but ends in a dark brown to black tip. Gray marmots have small, round, light-colored ears. Their cheeks are darker brown, while the area around their mouth is a lighter yellowish brown. Albinism has been recorded in this species. Gray marmots are not known to show sexual dimorphism (physical differences between males and females), though adult males are larger than adult females in most other marmot species. They also have both cheek glands and anal glands. Gray marmots inhabit mountain meadows and steppes. They forage on sage bush in spring, and on grasses and flowering plants in summer and fall. They occur at elevations from 150 to 4,000 m (490 to 13,120 feet), and tend to prefer mild to moderate, well-draining slopes with suitable soil for digging burrows; suitable soil ranges from fine-grained soft soil to soil that contains sand or pebbles. Their native distribution extends from the Altai mountains of southwestern Siberia (Tuva, Russia), western Mongolia, northwestern China (Xinjiang), and eastern Kazakhstan, into the Tien Shan mountains of northwestern China, Kyrgyzstan, and southeastern Kazakhstan. In southeastern Kazakhstan and southwestern Siberia, their range extends into lower elevation dry steppes. The gray marmot is an introduced species in the Caucasus mountains of Dagestan, Russia. In the Altai mountains of western Mongolia, the gray marmot’s range overlaps with the range of the Tarbagan marmot (Marmota sibirica). In this zone of overlap, competition from Tarbagan marmots restricts gray marmot habitat to elevations above 3,000 m (9,800 feet) in areas with scattered boulders and rocks. Observations of hybridization between the two species, and of the two species living in the same area, are rare. Gray marmots mate in early May, often mating inside burrows before they emerge from hibernation. Their mating system may be either monogamous or polyandrous. Gestation lasts 40 days, after which females give birth to litters of 2 to 6 young. Female gray marmots reach reproductive maturity at 2 to 3 years old. Females reproduce in alternate years, and will reabsorb embryos when environmental conditions are harsh.
