The chipmunk is a cute little rodent, a close relative of the squirrel. The Asiatic species was described by Laxman in 1769 as Tamias sibiricus and is placed in the genus Eutamias. Its American cousin Tamias striatus was described by Linnaeus in 1758
Origin and description
The Asian chipmunk differs from most of the inhabitants of the American continent by a not so clear pattern of stripes on the head and a number of other morphological features of the structure of the skull. The known remains date back to the beginning of the Holocene. Transitional fossils such as Miospermophilus Black have been found in Upper Miocene deposits in America, in the Irtysh basin.
With squirrels, this animal has close ties and is a transitional form from those who live in trees to burrows. Many North American squirrel species are closely related to chipmunks. In Europe, this is the genus Sciurotamias Miller, which lived in the mountain forests in the Asian southeast and lived in the west of Europe in the Pliocene, an ancient anthropogen is also represented in Eastern Europe (Ukraine).
Tertiary remains in Western Europe are found outside of present-day habitats. In the Pleistocene, the remains are found within the modern range. There are two directions of development in the tribe, they are represented by Tamias chipmunks – mammals living in coniferous and coniferous-deciduous forests, as well as Sciurotamias – Chinese tree species that live in the evergreen mountain hardwood forests of subtropics in Southeast Asia. They occupy a niche of squirrels there.
American individuals are represented by a wide variety, today 16 species are known. Almost 20 species of this rodent are grouped into two subgenera: North American inhabitants of deciduous forests and taiga animals of Eurasia. One species lives in the Russian Federation.
Appearance and Features
Chipmunks are easily recognizable by their alternating white and dark stripes on their head and back. There are five dark stripes on the back, with a brighter central one. Light stripes are pale-yellow or reddish-ocher tones, the belly is whitish. The tail is greyish above. Short summer and winter fur does not change in color and has a weak awn.
From below, the hair on the tail is laid out on both sides in the middle. The front legs are shorter, they have long fingers (3-4) of the same size, on the hind legs – the fourth longest. The ears are small with a sparse fluff. An Asian species that lives in Russia has a body length of 27 cm, a tail of 18 cm.
The main differences from the North American subspecies:
- the tail is longer;
- ears are shorter and slightly rounded;
- the dark marginal dorsal stripes and the anterior parts of the first pair of laterals are brighter ;
- the dark border of the light stripe on the muzzle from the eye to the end of the nose is brighter;
- the dark stripe on the cheek is wider and often merges with the dark marginal stripes of the back.
The coloration of chipmunks becomes darker from north to south. In the southern regions of the range, reddish hues increase from west to east, the top of the head, dark cheeks, rump, base of the tail are more brightly colored.
Interesting fact: In America, chipmunks love to feast on beech seeds and once they can place up to 32 pieces, but they cannot climb the smooth trunk of this tree. When the harvest is small, the animals use the maple as a “ladder”, when they see a bunch of nuts, they pinch off and go down to pick it up.
Where does the chipmunk live? ?
In Russia, the range border passes in the north of Siberia along the border of larch growth, in the northeast with the border of fir forests. In the north it rises to 68°N. sh. spreads over the basin, reaching the mouth, the Yenisei, the Indigirka.
In the west and south, it expands to Vologda, Vetluga, descends along the left bank of the Volga, captures the right bank of the Kama, Belaya, skirting the Urals, reaches Tara, Lake Chany, turning south, captures Altai, goes along the southern border of the country. Further, it is found everywhere to the most eastern lands, including islands, but is not found in Kamchatka. Outside of Russia, it lives in Mongolia, China, Korea, Japan.
The range of North America includes most of the east from southern Canada to the Gulf of Mexico, excluding a few regions of the southeast. In the Adirondack Mountains, it occurs at altitudes up to 1220 m. There it prefers deciduous and mixed forests and is most common in mature (old-growth) hardwoods of maple, beech.
The animal loves forests with multiple growth, felling and windbreaks, berries. In Asia, in the mountains, it rises to the very border of larch-cedar woodland and elfin. In clean forests, chooses places with dense grass. In some places it inhabits forest-steppe areas, occupying areas with shrubs and in ravines. Burrows are made by a rodent on high ground, in dry places, in stony placers.
What does a chipmunk eat?
In spring, rodents diligently examine the surface of the soil, looking for seeds left over from autumn. Since there are few of them at this time, shoots of shrubs and trees, buds, leaves go to food until new fruits and seeds appear. During spring, summer, autumn, the menu is supplemented by insects, earthworms, ants, mollusks. Sometimes the animals eat passerine eggs, carrion, even rare cases were noted when they hunted small birds and mammals. They love to eat flowers and berries: lingonberries, cherries, raspberries, bird cherry, mountain ash, viburnum.
The main food of these animals are the seeds of coniferous and deciduous trees. They especially love pine nuts. The menu includes seeds: hoof, wild millet, climbing buckwheat, buttercup, mountaineer, mouse pea, dog rose, umbrella, wild cereals, sedges and garden crops. They feed on sporangia of polytric mosses, mushrooms. Most of the diet consists of the fruits of maple, elm, linden, elm, spindle tree, Manchurian hazel.
At the end of summer, the rodent begins to replenish its pantries, collecting fruits and seeds of plants. He carries them for more than a kilometer. In total, the weight of such blanks can reach up to 3-4 kg. In Siberia and the Far Eastern lands, if there are crop failures of pine nuts, animals make mass movements to the fields of grain crops, peas, sunflowers, or focus on berries: lingonberries, blueberries, blueberries, etc.
To the list of main plants The food base of animals includes more than 48 species, of which:
- 5 – tree species (oak, larch, aspen, black and white birch);
- 5 – shrub (lespideza & # 8212; 2 species, wild rose, hazel, willow);
- 2 – semi-shrubs (lingonberries, blueberries);
- 24 – herbaceous (from cultivated & # 8212; wheat, rye, peas, millet, barley, sunflower, corn, etc.).
Most of the American Animal's diet consists of nuts, acorns, seeds, mushrooms, fruits, berries, and corn. They also eat insects, bird eggs, snails, and small mammals such as young mice. In pantries, the rodent keeps stocks of seeds of various plants (98%), leaves, larch needles and terminal shoots. At one time, a rodent can bring more than eight grams in its cheek pouches.
An interesting fact: In the 30s of the last century, a pantry was found in Primorsky Krai, where a chipmunk collected 1000 g of rye, 500 g of buckwheat , 500 g of corn, as well as sunflower seeds. Wheat grains of 1400 g and 980 g were found at the same time in two other burrows.
When eating food, the rodent holds fruits and seeds in its dexterous front paws. With the help of long incisors directed forward, he extracts the kernels from the shell or extracts the seeds from the box. Then, he uses his tongue to slide them back and slip them between his teeth and the stretchable skin around his cheeks. There they are kept while the animal is busy gathering food.
Cheek capacity increases with age. When the cheek pouches are full, the animal takes the seeds to its nest or digs them into shallow holes, which it digs in the ground, and then masks with earth, leaves and other debris.
Features nature and lifestyle
The animal spends most of its day gathering seeds, which are its most important food source. Although most species forage most often on the ground, they all easily climb trees and shrubs to collect nuts and fruits. The animal is active during the daytime. With the onset of winter, the rodent hibernates even in the southern regions of Russia. On the American continent, the animals do not hibernate for the whole winter, but they do not leave their holes, they sleep for several weeks, periodically waking up to eat, some individuals also behave in the southern part of the range in Mongolia.
In the European part of the Russian Federation, pair colonization occurs in one nest. In regions with permafrost, there is only one chamber in the burrow, in these cases the pantry is located below the nest. The rodent makes tunnels for itself and builds chambers underground. He makes entrances to them in inconspicuous places among bushes or in stones, under rocks. Some species can make nests in hollows and spend a lot of time in trees.
Most burrows consist of one entrance that leads to an inclined tunnel, about 70 cm long. At its end there is a nesting chamber, 15 cm to 35 cm in diameter, lined with dry grass, fluff from seed heads, and crushed leaves. He hides seeds of plants, nuts under the nest or in a separate chamber, providing himself with a supply of food for the cold season. There are tunnels up to four meters, with branches and side nests. There are no traces of feces in the dwellings of the animals, he makes latrines in the side vents.
In the spring, as soon as it gets warmer and the snow begins to melt, the rodent wakes up. In summer, rodents arrange shelters in hollows, in trunks of fallen trees and stumps. With the onset of cold weather, chipmunks disappear underground. At present, it is not known exactly what happens when the animals retire to their burrows for the winter. It is believed that they immediately go into a state of torpidity. In this state, body temperature, breathing rate and heart rate drop to very low levels, which reduces the amount of energy needed to sustain life. From the first warm days of spring, animals begin to appear, sometimes breaking through the thickness of the snow.
Social Structure and Reproduction
These animals are solitary. Each has its own burrow and ignores its fellows, except when conflicts arise, and also during mating, or when females take care of their children. Each animal has its own territorial area (0.04-1.26 ha), sometimes these areas overlap. Territories in adult males are larger than in females and juveniles. Boundaries are constantly changing and dependent on seasonally available food sources. Most animals maintain roughly the same range from season to season.
The animals spend most of their time near the burrow. In this place there are no zones of overlap with the territory of other individuals, and the host dominates here. Violators quickly leave the site, avoiding direct collisions. These dominance boundaries are more stable than range zones. A chipmunk makes different sounds when frightened and detecting danger: a whistle or a sharp trill, similar to a creak. Sometimes he seems to chirp, it's like “zwirk-zvirk” or “chirk-chirk” with an interval of a couple of seconds. This sound is most commonly heard when the animal is following someone from a safe distance.
The rut in mammals begins in April. Females mate repeatedly with one or more males during the estrous period, which lasts 6-7 hours. Starting from the end of May until the second decade of June, they bring 3-5 cubs in a litter. Newborns weigh about 3 g, they are blind and naked. The hairline begins to appear from the tenth day, the ear canal opens from the 28th, the eyes from the 31st day. The babies come to the surface at the age of six weeks and begin to forage on their own. At first, they are not too shy, but as they grow older, they become more cautious.
In early autumn, fingerlings already reach the size of an adult animal. Sexual maturity occurs in the second year, but not all of them start breeding at this age. In some habitat regions, females can also bring a second litter: in the North. America, Primorye, Kuriles. The average life expectancy is 3-4 years.
Chipmunks' natural enemies
Numerous predators hunt animals:
- black ferrets;
- raccoon dogs;
This is a very curious animal, it often enters villages, summer cottages, vegetable gardens, where it becomes prey for dogs and cats. In some places, hamsters not only eat the supplies of the striped owner of the pantry, but even himself. In Vost. Siberian bears, digging tunnels, empty storerooms and eat rodents. Snakes are also included in the list of enemies of the animal. Of the birds, they are hunted by the sparrowhawk, goshawk, kestrel, buzzard, sometimes an owl, but less often, since these birds are nocturnal, and rodents are active during the day.
Rodents are often mortally wounded during fights that occur during the rutting season. Males fight for females. Females may defend their territory by guarding the nest from other juveniles. They may be attacked and injured by other, larger rodents such as squirrels. Natural disasters can affect the number of chipmunks: fires, which quite often occur in the Siberian taiga, lean years. Parasites such as tapeworms, fleas, mites can cause malnutrition, less often death.
Population and species status
This type of rodent is represented by a large population and has a wide distribution. There are no real threats to reduce the number. Most of the species' range is in Asia, with European borders extending further west of Europe. It is found from the northern European and Siberian part of Russia to Sakhalin, capturing the islands of Iturup, and Kunashir, from extreme eastern Kazakhstan to northern Mongolia, northwest and central China, extends to northeastern China, is in Korea and Japan from Hokkaido, Rishiri, Rebuna.
In Japan, the chipmunk has been introduced to Honshu in Karuizawa. It is also represented in Belgium, Germany, the Netherlands, Switzerland and Italy. In Mongolia, it lives in forest areas, including the Khangai, Khovsgel, Khentii and Altai mountain ranges. All in. America is a different kind of — Tamias striatus is widely distributed throughout the eastern United States and adjacent Canada, from southeast Saskatchewan to Nova Scotia, south to western Oklahoma and eastern Louisiana (in the west), and to coastal Virginia (in the east).
Chipmunks are not in danger and are listed as Least Concern. This rodent helps in spreading vegetation over vast areas. He keeps his savings in burrows. Stocks of seeds not eaten by an animal are more likely to germinate underground than on the surface.
Rodents harm, sometimes very strongly, agricultural plantations, climb into warehouses and granaries. They spoil cucumbers, gourds, eating away their seeds. Chipmunk, consuming plant seeds, reduces the seed fund of valuable species (oak, cedar, larch), on the other hand, it is a competitor to animals and birds, which are competitors in the diet.
This is interesting: In 1926 year (Birobidzhansky district), the animals destroyed the entire grain crop.
If there are many animals, they can interfere with the normal reforestation of some trees, especially pines, eating their seeds. But hunting them, especially baiting with pesticides, is not an acceptable means of control due to the harmful effects on other wildlife, including wild birds. Chipmunk — a beautiful, very curious animal often catches the eye of people, delivering a lot of pleasure to tourists and travelers. Our forests would be much poorer if this little striped rodent did not live in them. It is easily tamed and kept in cages at home.