Marmota himalayana
Himalayan marmot

Himalayan marmots (Marmota himalayan) are 1 of 14 Marmota species alive today. While members of the genus Marmota occur across portions of Asia, Europe, and North America, Himalayan marmots are restricted to high elevation regions of northwestern south Asia and China. In Asia, Himalayan marmots occur across the Himalayan Mountains of India, Nepal, and Pakistan. In China, they are found in several provinces, primarily across the Tibetan Plateau in western, central, and southern portions of the country. (Molur and Shreshtha, 2008; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

Himalayan marmots are found most often between timberline and snowline, at elevations of 3,500 to 5,200 m. Temperatures in these areas typically range from 8 C to 12 C. Himalayan marmots occur primarily in dry, open habitats, including alpine meadows, grasslands, and deserts. Much of their habitat falls within the Northwestern Himalayan alpine shrub and meadows ecoregion. Vegetation in this ecoregion is dominated by stunted evergreen shrubs and birch-dominated forest patches. At higher elevations, this shrub-dominated community shifts to open alpine meadows. This ecoregion is largely protected due to the presence of critically endangered snow leopards. Like other marmots, Himalayan marmots dig large burrows, which generally restricts them to areas with light-textured and adequately deep soil. The burrows of Himalayan marmots are exceptionally deep, typically ranging from 2.0 to 3.5 m. In preparation for hibernation, Himalayan marmots dig burrows that are considerably deeper, sometimes reaching depths of 10 m. These burrows are shared by all members of the colony during hibernation. (Jin-hui, et al., 2009; Molur and Shreshtha, 2008; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

Members of the genus Marmota are generally referred to as large ground squirrels. Marmots are large terrestrial rodents with stout limbs and short tails. Himalayan marmots are similar in size to an average house cat. They are generally larger than other marmot species across their native range. Himalayan marmots are particularly stout-bodied and range in length from 475 to 670 mm. They have relatively large skulls, ranging from 96 to 114 mm in length, and exceptionally large hind feet, which range in length from 76 to 100 mm. Like other marmots, each forefoot has four-toes with long concave claws for burrowing, and each hind foot has five toes. Despite their large body size, Himalayan marmots have shorter tails than many other marmot species. Their tail length ranges from 125 to 150 mm, comparable to that of gray marmots. Their ears, ranging from 23 to 30 mm in length, are also relatively short compared to other marmot species. Dorsal pelage ranges from yellow to brown, and they often have irregular black or blackish brown spots, particularly on the face and snout. Ventral pelage is buff yellow to russet. Two subspecies of Himalayan marmots have been described: M. himalayana himalayana and M. himalayana robusta. Marmota himalayana robusta is especially large, with individuals reported to weigh over 6 kg. In general, Himalayan marmots range in mass from 4 to 9.2 kg. Sexual dimorphism has not been reported in this species. (Barash, 1989; Hoffmann and Smith, 2008; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

Most marmot species are cooperative breeders, and many species live in family groups consisting of a reproductive territorial pair, subordinate adults, yearlings and young. Although most marmots are monogamous, in some species, females have multiple mates. Special care is provided during hibernation, when other adults aid in social thermoregulation of the young. This may be a form of alloparental care, whereby unrelated adults aid in care of the offspring. (Armitage, 1999; Barash, 1989; Blumstein and Armitage, 1999; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

All species of marmots (Marmota spp.) reach reproductive maturity by the age of two. However, reproduction typically is delayed another year or more. When marmots reproduce early in the year, it is more physically stressful. Because female marmots do not gain body mass during lactation (and may lose body mass), early reproduction represents a risk, as these individuals must rely on favorable future food availability and weather conditions to sustain their reproductive effort. Reproductive females gain mass at least three weeks later than barren females, but this time period typically is adequate to restore body mass similar to that of barren females. The inability of pregnant females to maximize fattening may lead to reproductive skipping (failure to wean their young). This occurs in most marmot species. (Armitage, 1999; Barash, 1989; Blumstein and Armitage, 1999; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

Annual mating in Himalayan marmots occurs during February and March, and gestation lasts up to one month. Like most marmots, Himalayan marmots give birth in late spring and early summer. This coincides with the end or near end of hibernation. Himalayan marmots typically produce 2 to 11 offspring per litter. Variation in litter size often reflects overall population density. When population density is high, females yield an average of 4.8 offspring per litter. In less dense populations, females average 7 pups per litter. After parturition, offspring are weaned over a 15 day period. Once offspring are independent, juveniles maintain permanent residences in their familial communities, which is typical of most marmot species. (Burton and Burton, 2002; Hoffmann and Smith, 2008)

Most marmots provide considerable care to their offspring. In many species, such as Olympic marmots, offspring remain in the burrow for at least one month after birth. In Himalayan marmots, milk is provided to the young during the first 15 days of life. Most marmots receive nearly constant care from the mother, both while in the burrow and for several weeks after emerging. After several weeks, offspring of most species are capable of foraging independently. Blumstein and Armitage (1999) discuss similarities and differences in cooperative breeding and alloparental care across marmot species but note that little is known about this aspect of Himalayan marmot reproduction. (Blumstein and Armitage, 1999)

Himalayan marmots have an average lifespan of 15 years in the wild. They are rarely held in captivity and thus, there is no information available concerning the average lifespan of individuals under these conditions. Typical lifespans for Marmota species ranges from 12 to 17 years. (Burton and Burton, 2002; de Magalhaes, et al., 2009)

Like all marmots, Himalayan marmots are diurnal, with activity peaking during morning and late afternoon. All marmots are social, living in colonies of up to 30 individuals. In Himalayan marmots, colony size is largely dependent on resource availability. A visible social interaction among marmots is their greeting, a behavior common to many rodents. This greeting occurs after a period of separation, such as when individuals emerge from their burrows in the morning or afternoon. The greeting consists of a nose-to-nose or nose-to-mouth interaction, but can progress into a nose-to-cheek exchange. Marmots are also known to "play fight". Although these interactions appear aggressive, they typically are not, and the length of play fights varies with age and sex. Mock fights among female marmots and yearlings are typically of longer duration than those among adult males and infants. (Armitage, 1999; Barash, 1989; Hoffmann and Smith, 2008; Nikol’skii, 2007; Sun, et al., 1989)

Himalayan marmots exhibit seasonal variation in behavior. They hibernate for extended periods, typically for 6 to 8 months during the coldest times of the year. They are active in spring, summer, and early autumn. Adult females and yearlings spend more time inside their burrows during late spring and early summer. Adult males spend more time outside their burrows, being alert and presumably scanning for potential predators, until August. By mid- to late-August, both sexes spend increased amounts of time in their burrows. (Armitage, 1999; Barash, 1989; Hoffmann and Smith, 2008; Nikol’skii, 2007; Sun, et al., 1989)

There is no information available regarding the average home range size of Himalayan marmots.

Marmots have strong tactile senses, well-developed for burrowing. Quick reflexes also allow marmots to respond rapidly to their wide range of environmental influences and social interactions. Marmots are highly alert and rely heavily on visual and auditory senses to alert them to potential predators. Per-capita time spent scanning decreases as colony size increases. For example, Olympic marmots tend to spend less time watching for predators, since they commonly forage in groups. In contrast, individuals that forage alone continually pause, scanning the surrounding environment for predators. In comparison to marmots feeding in groups, individuals spend nearly twice the amount of time watching for predators. Distance from their home burrow also affects alertness. For example, yellow-bellied marmots in close range of their burrows, tend to be less vigilant in scanning their surroundings than those foraging at greater distances. (Barash, 1989; Thorington Jr. and Ferrell, 2006; Wolff and Sherman, 2007)

Himalayan marmots often communicate by whistling or chirping, and using physical behaviors. When a predator is detected, they produce a series of alarm calls, which have been observed in many marmot species. It is unclear if there is a distinct vocalization associated with mating. In some species, such as woodchucks, males attract reproductive females using pheromones. Certain physical interactions, such as nestling and nibbling, indicate an individual is ready and willing mate. Because of their burrowing tendencies, Himalayan marmots are difficult to observe in their natural habitat. As a result, few detailed studies of their mating behavior have been conducted. (Barash, 1989; Thorington Jr. and Ferrell, 2006; Wolff and Sherman, 2007)

Himalayan marmots (M. himalayana) are herbivores. Old plant growth is commonly avoided due to the presence of alkaloids, which emit a bitter, metallic taste. Most marmots prefer flowering plants because they are more palatable, and select forage containing higher amounts of protein, fatty acids and minerals. Plant selection differs throughout the year since certain flora species are only available seasonally. Himalayan marmots are sometimes sympatric with livestock (e.g., domesticated yaks) and feed in the same pastures. (Armitage, 2003; Barash, 1989; Burton and Burton, 2002; Nikol'skii and Ulak, 2006; Sun, et al., 1989)

Predators of Himalayan marmots include snow leopards, Tibetan wolves, and large birds of prey like bearded vultures and golden eagles. Himalayan marmots are important prey for snow leopards, and evidence suggests that they make nearly 20% of the snow leopard diet. Brown bears may also prey on Himalayan marmots. (Aichun, et al., 2006; Nikol'skii and Formozov, 2005; Oli, et al., 1993)

Marmots are typically on watch for predators while out of their burrows. Distance from burrow and colony size are correlated with per-capita time spent scanning, as greater distances and smaller colonies results in more time spent scanning. When Himalayan marmots sense a predator approaching, they use a distinct series of calls to alert other members of their group. These alarm calls consist of rapidly repeating sounds, beginning with a low frequency call. Each call typically lasts less than 80 milliseconds. A single series of calls continues for less than 1 second. Alarm calls are repeated usually every 5 to 20 seconds. Alarm calls in Himalayan marmots can be distinguished from those produced by other marmots, as the first and second sounds in each series occur in much more rapid succession. (Aichun, et al., 2006; Nikol'skii and Formozov, 2005; Oli, et al., 1993)

Himalayan marmots are important prey for snow leopards, which are classified as endangered on the IUCN's Red List of Threatened Species. They are also important prey for a number of other predatory mammals and birds. As burrowing animals, they likely help increased soil aeration and water penetration throughout their geographic range. In addition, abandoned borrows likely serve as habitat for numerous other species of small mammals. There is no information available regarding parasites specific to this species. (Aichun, et al., 2006; Oli, et al., 1993)

Historically, the flesh of Himalayan marmots reportedly was used in traditional Tibetan medicine, for treatment of renal disease. (Sun, et al., 1989)

There are no known adverse effects of Himalayan marmots on humans.

Although current population trends are unknown, Himalayan marmots are classified as a species of least concern on the IUCN's Red List of THreatened Species. They are locally abundant throughout their geographic range and show no signs of decline. This species occurs in habitats protected for snow leopards, which is classified as endangered by the IUCN. As a result, they are relatively unaffected by human impacts throughout much of their range. (Molur and Shreshtha, 2008)