BLACK-CAPPED MARMOTS: CHARACTERISTICS, BEHAVIOR AND REPRODUCTION

BLACK-CAPPED MARMOTS

pair of Black-capped marmots in Kamchatka

Black-capped marmots (Marmota camtschatica) are marmots — large ground squirrels and rodents in the family Sciuridae (squirrel) family — endemic to the Russian Far East in a range that is divided into three main parts, each with its own subspecies. These marmots lives in arctic tundra and alpine habitats from near sea-level to an altitude of 2,000 meters (6,600 feet). Depending on the subspecies they hibernate for six to eight months each year, which is long for a marmot or for that matter any mammal. [Source: Wikipedia]

Black-capped marmots are relatively small marmot. Their head-and-body length is around 39.5 to 61.5 centimeters (15.6 to 24.2 inches) and they weigh 1.65–5.4 kilograms (3.6–11.9 pounds) and have a short tail. Their backside fur dorsal pelage is a grizzled yellowish-grey and their underparts are cinnamon or rusty brown. The limbs are paler while the tail is darker — brownish-black. The upper part of the head is brownish-black, and this colour continues to the mid-back as a dorsal stripe.

Black-capped marmots are one of the most northern-living land animals, living in some the coldest places on earth (See Below). They feed on grasses, herbs and mosses. They live in colonies formed from many separate burrows, each occupied by an adult pair and their offspring. A litter consists of five or six young but these stay in the family group for at least three years. The marmots congregate in larger groups to hibernate. The sleeping chamber has large quantities of bedding material and the entrances are plugged.

Black-Capped Marmot Habitat, Range and Subspecies

Black-capped marmots are Palearctic (Eurasian) mammals that have a patchy distribution throughout northern and eastern Siberia, or the eastern portion of the Russian Federation. They live in upper northern latitudes and polar regions in tundra, taiga, and mountains at elevations of 20 to 2000 meters (65.62 to 6562 feet). They are typically found in burrowsup to one meter (3.28 feet) underground at an average depth of 0.25-0.6 meters. Temperatures are usually very low where black-capped marmots lived. For example, along the Lena River in Yakutia temperature fall as low as -34°C in the winter. Summer temperatures in the region they occupy may reach 25°C. In general, winters are long and have little snow. Temperatures that may fall as low as -70°C. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

There are currently three recognized subspecies of black-capped marmots, and each of which is geographically isolated: 1) Kamchatka marmots (M. c. camtschatica), which are found on the Kamchatka Peninsula, and the Mil’kovski area along the valley of the Yurtinaya River. 2) Barguzin marmots (M. c. doppelmayeri), which occupy a portion of Buryatia in the Severobaikal’sk area, or more specifically the north-eastern portion of Prebaikalia (Baikal Mountains) as well as the northern portion of Transbaikalia (Barguzin Mountain Range); 3) Yakutian marmots (M. c. bungei), which live along the eastern side of the Lena River in the Kharaulakhskii Mountain Range in Yakutia, Russia. Yakutian marmots occupy one of the most northern parts of Russia, inhabiting the north-eastern part of Yakutia. The range of Yakutian marmots extend from the delta of the Lena River, or along the Kharaulah ridge, south along the Momsky, Chersy, and Verkhoyansky Mountain ridges as well as along the lower part of the Yana River.

Yakutian marmots occupy mountain slopes 20 to 1500 meters (4920 feet) above sea level and Kamchatka marmots typically inhabit areas 600 to 1500 meters above sea level. Habitat sites appear to be selected based on altitude, plant composition, and sun exposure. Black-capped marmots prefer bare mountain slopes that are exposed to the maximal amounts of sunlight — south or south-west facing slopes. They are often found above the treeline of dwarf pine and alder. Grasslands, steppes, and mixed rock/grass areas seem to be preferred over forested areas and other closed environments.

Sites inhabited typically have dry, well-drained, soft or fine soils. The soils may contain silt, but may also have water and glacial deposits that include large boulders, broken rock, and finer deposits. Winter burrows are often created in clay soils. The upland, alpine treeless areas of eastern Siberia and Kamchatka are underlain by permafrost and covered with rocky soil and a few grasses. Black-capped marmots are semi-fossorial (engaged in a burrowing life-style or behavior, and good at digging or burrowing). Permafrost and rock prevents burrowing to extensive depths. Burrows may only reach depths of 0.25 to 0.6 meters below the surface, which equates to the depth that the ground thaws during the summer. However, some mountain slopes have thicker soils and thaw to a depth of one meter.

Black-Capped Marmots Characteristics

Black-capped marmots range in weight from 2.0 to 7.5 kilograms (4.4 to 16.5 pounds) and have a head and body length that ranges from 45 to 51 centimeters (17.7 to 20 inches), with atail that is 12.5 centimeters (five inches) lonf.. The top of their heads are black from the tip of the nose to behind the ears. The sides of their heads are black to about the level of the eyes, and then sandy yellow mixed with gray below the eyes. A black line carries down the back of the neck to the shoulders. Their lips are black and throats are orange. Their ears are orange to sand colored. Sexual Dimorphism (differences between males and females) is present: Males are larger than females. The average head-body length of male is 47.3 centimeters; that of a female is 45.8 centimeters. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Marmots have six pads on the soles of their hindfeet, but the shape of these pads differs for each species. The posterior pair of foot pads in black-capped marmot is elongated compared to some other marmots. Black-capped marmot female may have five or six pairs of mammae. As black-capped marmots get older, their color fades. Juvenile marmots go through three fur stages. First, juveniles have a soft, dense underfur with a brownish-black to black cap and similar-colored dorsal guard hairs. The initial guard hairs are shed, resulting in the second fur stage. During the third fur stage, juveniles grow a fur that more closely resembles the adults of its species.

pair of black-capped marmots in Kamchatka playing

Marmot size, both mass and body length, varies across the geographic range with smaller black-capped marmots in the southern part of the range and larger ones in the northern part of the range. The weight of black-capped marmots ranges from two to 7.5 kilograms,with greater masses noted just before hibernation and lower masses noted after hibernation Adult Yakutian marmots weigh approximately two to four kilograms. Barguzin marmots weigh around three kilograms,and Kamchatka marmots have an average mass of about 4.5 kilograms. No information is available regarding specific metabolic rates of black-capped marmots, but energy expenditures may increase by eight to 15 times between hibernation and active time periods. It has also been noted that animals inhabiting mountainous regions with low temperatures (5 to 10°C) have lower metabolic rates than species that live with higher temperatures

Black-Capped Marmot Food and Eating Behavior

Black-capped marmots are primarily herbivores (eat plants or plants parts) but can also be recognized as folivores (eat leaves), frugivores (eat fruits), granivores (eat seeds and grain), and lignivores (eat wood). Animal foods include insects. Among the plant foods they eat are grasses, forbs (herbaceous flowering plants), fruits (berries), seeds (including conifer cones), shrubs, roots bulbs, tubers wood, bark, stems, nuts and flowers. Early plant growth is preferred over later growth. Black-capped marmots obtain water from mountain streams, their food, and from melting snow or glaciers. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

The short three-to-four month growing season of the region where black-capped marmots lives makes it difficult for them to obtain the fat reserves necessary to survive hibernation. There is often little or no food available when the marmots start to emerge from hibernation, which is often why the pregnant female remains in the burrow until she gives birth in June.

Roots and bulbs are consumed most towards the end of the summer when the marmots are trying to increase fat stores. As many as 12 different plant species are consumed, and seeds from Siberian dwarf pines (Pinus pumila) are consumed just before the marmots enter hibernation. Some of the specific species consumed by Kamchatka marmots include arctic herbs (Anemone sibirica), granny's bonnets (Aquilegia glandulosa), Doronicum flowers (Doronicum bargusinense), Asian globeflowers (Trollius asiaticus), and cranesbills (Geranium albiflorum). All parts of a plant may be consumed, including the flowers, leaves, stems, and roots.

Black-Capped Marmot Behavior

Black-capped marmots are terricolous (live on the ground), fossorial (engaged in a burrowing life-style or behavior, and good at digging or burrowing), diurnal (active during the daytime), motile (move around as opposed to being stationary), sedentary (remain in the same area), hibernate (the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal’s energy requirements) and social (associates with others of its species; forms social groups). Black-capped marmots use large rocks as look-out posts duriing vigilant behaviors. Adults have an alert posture, where they sit upright on their haunches and scan their surroundings.

The size of their range territory is one to 21 hectares (2.5 to 50 acres), with their average territory size being 13 hectares. Home ranges occupied by black-capped marmots vary in size depending on the quality of the site. Territories include summer and winter burrows as well as foraging areas and other required resources. Among Kamchatka marmots family home ranges do not overlap, and small marmot colonies are often formed.[Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Black-capped marmots endure extreme conditions throughout the year and their behavior doesn;t seemed to be shaped so by the amounts daily sunlight, which varries a lote between summer and winter. They forage extensively during the summer to put on weight in preparation for hibernation. But despite almost 24 hours of daylight in summer months, studies have found that black-capped marmots follow a typical diurnal circadian rhythm. At night, they rest and seek shelter in their burrows, but during the day, or when the sun reaches an angle of 17°, aboveground activity begins. Daily activities have not been found to end at a particular angle of the sun as occurs when activities begin.

Feeding patterns seem to follow a bi-modal cycle with marmots most active first thing in the day and then again later in the day. When temperatures reach 15-25°C, black-capped marmots seek shelter in their burrows, only re-surfacing to feed once temperatures decrease. Dispersing adult males that have yet to find a territory are nomadic, spending one to three nights in any particular burrow before moving on to the next. The solar altitude plays a significant role in the daily activity pattern of family groups of black-capped marmots. They usually eliminate heat by lying on rocks or by entering the burrows.

Black-Capped Marmot Social Behavior, Burrows and Communication

Black-capped marmots are a very social species that live in isolated family groups. Family groups include a reproductive pair and its offspring. Offspring may include yearlings, juveniles from the current breeding season, and male and female subordinate adults (sexually mature offspring that have not dispersed). Male offspring may disperse into uninhabited territories when they are 2-3 years old. Kamchatka marmot families average 1.8 adult males, 1.7 adult females, and 4.3 young. The size of the family depends on the amount of resources available. Studies have shown that black-capped marmots may move between family groups, indicating that groups may not consist of only close relatives. A black-capped marmot burrow excavated during the winter revealed two adults, four sub-adults, and four juveniles. This finding supports the theory that the family group not only shares the same summer territory but also exploits joint hibernation. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Burrowing activities occur during the summer. When the ground thaws black-capped marmots are able to add on to their extensive underground tunnels and some tunnels have been found to reach 113 meters in length. Burrows are the cumulative result of many generations of marmots adding on to existing systems. The main area where the marmots live are gathered in two larger rooms typically so the family can hibernate in these areas. This is usually where the females give birth.[7]Each burrow has multiple openings and multiple chambers. Burrow openings are under or near large rocks and 17 to 18 centimeters in diameter. Three types of burrows, summer, winter, and temporary, can be found throughout the marmot home range, and are maintained during the summer. /=\

Black-capped marmots communicate with vision, sound and chemicals usually detected by smelling. Similar to other marmot species that inhabit mountainous regions, they use their tails in visual communication and leave scent marks produced by special glands in their anus and cheeks and placed so others can smell and taste them. Territories may be marked using different olfactory cues, and vocalizations are used to indicate marmot presence on those territories. Marmots direct antagonist behaviors towards intruders while more amicable behaviors are directed towards relatives. Black-capped marmots use vocalizations such as alarm calls to notify group members of nearby predators. The duration of the main call is 0.2 seconds and has an average frequency of 3000 Hz. Kamchatka marmots have a unique alarm call compared to the other two black-capped marmot subsepcies, Barguzin and Yakutian marmots.

Black-Capped Marmot Hiberbation and Adaptions to Cold

Black-capped marmots have physiological and behavioral adaptations that enable them to survive in cold environments with permafrost. Compared to other marmots, they have a higher percentage of their body mass consisting of subcutaneous and perivisceral fat. This fat also does not solidify until temperatures reach -3°C to -7°C. Black-capped marmots have the ability to forego moulting on all or part of their body to reduce energy expended growing new fur. Winter burrows, or hibernacula, are constructed in areas that receive deep snow cover during the winter. The hibernaculum is prepared for the winter by insulating the roof and walls. The roof of the burrow is covered with rocks and the walls of the burrow are lined with as much as nine to 12 kilograms of grass and other vegetative material to assist with heat retention during winter.

Black-capped marmots hibernate for eight ot nine months from September to mid-May depending on the environmental conditions and how long food sources are available aboveground. The last marmot to enter the hibernacula plugs the entrance in such a way that air spaces become trapped in the plug material. This plug consists of plant material, soil, feces, and rocks, and not only provides increased insulation but also provides protection from predators. Arousals occur every two to four weeks, in which case the marmots are believed to defecate and urinate. In addition to saving energy by group hibernating, black-capped marmots have the ability to lower body temperatures to around 0°C during hibernation, and hibernate when ambient temperatures are below 0°C. Even during arousal periods, body temperatures do not rise to their usual active body temperature. Marmots also roll into balls and press together while in hibernation.

In addition to cold temperatures, hibernation, also begins as a result of food deprivation and body fat content. From February to March, black-capped marmots were found to have the deepest bouts of torpor. Adult torpor bout length typically decreased in duration in mid-April, or when the marmots were nearing the time to mate. Juveniles have long torpor bouts into May with some bouts stretching for 20 days.

Black-Capped Marmots Mating, Reproduction and Offspring

Blacked-caped marmots live in family groups consisting of one dominant reproductive pair and several offspring. They are monogamous (have one mate at a time) and engage in cooperative breeding (helpers provide assistance in raising young that are not their own). Offspring exhibit delayed maturity and delayed dispersal. As a result, family groups exhibit reproductive suppression and cooperative breeding. Inbreeding may occur if reproductive suppression is not complete. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Blacked-caped marmots engage in seasonal breeding. They mate in April in their burrows before they emerge from hibernation in mid-May and females bear a litter every two or more years. The number of offspring ranges from three to 11, with the average number being five. On average females and males reach sexual or reproductive maturity at three years because of their social system neither males nor females reproduce for some time after they reach maturity.

The severe cold and environmental conditions of the blacked-caped marmots habitats do not allow female marmots to build up enough energy stores to hibernate, grow, reproduce, and maintain daily activities to produce a litter every year. Subordinate females do not produce litters even during the years when the dominant female has not produced a litter.

Parental care is provided mainly by females but males and other adults may also help out. Young are altricial, meaning they are born relatively underdeveloped and are unable to feed or care for themselves or move independently for a period of time after birth. Nests are constructed in the burrow from dried vegetation. Young are born in early to mid-June, and may occur before or up to one to two weeks after the mother emerges from the burrow after hibernation. Newborns weigh about 33 grams and about 10.7 centimeters long. Marmot offspring are weaned and become independent at least 30 to 42 days after birth, but remain with their parents for several years. Young inherit the territory of their parents, mother or father. Both parents and subordinates provide thermoregulatory benefits to the juveniles during hibernation, by hibernating in a group and helping maintain an optimal hibernacula temperature. The offspring have the potential to inherit the home range if either of their parents dies.

Black-Capped Marmots Predators and Ecosystem Roles

Animals that prey on black-capped marmots include gray wolves, brown bears, golden eagles, wolverines, and red foxes. Other raptors such and hawks and owls and mid- to large-sized carnivores may also prey on them. Since lynxes feed on marmots in North America, Eurasian lynxes may consume marmots in Russia. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Burrows are the main line of defense for black-capped marmots against predators in both summer and winter. The plugs placed in the entrances to the burrow during hibernation, prevent predators from attacking the sleeping marmots in winter. Alarm calls are used to alert others if a predator is sensed. The coloration of black-capped marmots serves as camouflage.

Black-capped marmots significantly alter their environments through foraging and burrowing activities, which in turn alters the vegetation community. Areas immediately surrounding black-capped marmot burrows are predominantly covered by grasses with some mosses, lichens, and fungi present. The open tundra and the region surrounding the core area around the burrows typically have a greater proportion of mosses, forbs (herbaceous flowering plants), and cryptograms (algae, fungi, lichens and mosses) compared to the core area. Burrowing disturbs the soil, altering decomposition, moisture and nutrient cycles, as well as provides soil aeration. Nutrients, seeds, and soil brought to the surface may promote further plant growth. Marmots also distribute nutrients throughout their range through urination and defecation.

Black-Capped Marmots, Humans and Conservation

On the International Union for Conservation of Nature (IUCN) Red List black-capped marmots are listed as a species of Least Concern. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. The environments inhabited by black-capped marmots are not often close to human populations. Therefore black-capped marmots are not impacted much by humans unless there is mining or oil or natural gas extraction in areas they inhabit. However, researchers reported that black-capped marmot populations are declining and they are no longer found in some of their previous ranges. [Source: Lindsey Bylo, Animal Diversity Web (ADW) /=]

Humans have utilized black-capped marmots for food and hunted and trapped them for their fine, soft fur — practices that were more common in the past than now. The black-capped marmot is a host to a particular flea (Oropsylla silantiewi) and have the potential to be carriers of the plague but the risk to humans is seen as minimal. Marmot groups are often eradicated if their home ranges overlaps with human settlements, particularly if marmots are believed to compete with reindeer for forage.

Black-capped marmots numbers and population sizes are not well known because they are widespread and not found at high densities in remote places. Marmot densities fluctuate from two or three to 32 marmots per 10 square kilometers. At least two populations of Yakutian marmots are endangered and have been listed in the Red Book of the Sakha Republic/ Within the Marmot genus, Yakutian marmots are considered one of the most susceptible subspecies to extinction. Barguzin marmots are rare and protected by law. Laws also regulate the hunting of all black-capped marmots.

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, CNTO (China National Tourism Administration) David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated April 2025