Tundra shrew. Transarctic shrew (Arctic shrew) - Sorex jacksoni. Such a rodent is active all day and all year
Which differ among themselves not only in habitat, but also in size. These are small animals, the distinctive features of which are a long tail and an elongated muzzle.
Body size can range from 5 to 10 cm, depending on the variety. Tail - from 3.5 to 7.5 cm. Weight - from 2.5 to 15 grams.
The whole body is covered with fine dark hair, in most species it is brownish-gray. The abdomen is light. The tail is covered with thick short hair.
Tops of the teeth have brownish red color - thanks to this, the animal got its name. However, the older the shrew, the stronger her teeth are erased, and this color may gradually disappear. Dental formula of the shrew: incisors 3/2, canines 1/0, premolars 3/1, molars 3/3.
The ears are small, almost do not protrude above the surface of the coat. The eyes are black, but due to the predominantly underground lifestyle, vision is poor and poorly developed.
As a result, the animal searches for food using a powerful sense of smell or echolocation.
Shrews - one of the oldest branches of mammals, and their teeth have a clear division into fangs, incisors, molars.
REFERENCE! All animals of this species have a strong smell of musk, which is why many predators, having caught a shrew, refuse to eat it and abandon it.
The imprints of the animal are shallow, small, usually arranged in pairs. When there is no hard crust on the snow, a clearly distinguishable tail print remains.
Distribution and reproduction
Shrews are common in many countries. Most often they are found in North America, northern Asia, and Europe.
This is the most common species that can live in any conditions - forests, forest-steppes, tundra, sometimes even in floodplains of steppe rivers and meadows. Does not settle in wetlands.
About 15 species live on the territory of Russia, which are quite difficult to distinguish from each other (read about where the shrew lives and what it eats). The main features here are the details of the body structure and the genitals.
They live everywhere, from Moscow to Primorsky Krai and Sakhalin.
In the taiga zone normal amount of animals is in the range of 200-600 individuals per hectare, in tundra conditions - 3-5 times less.
The average lifespan of a shrew is 1-1.5 years. It begins to breed in the second year, immediately after the end of the winter period.
Creates nests in the form of a ball of plant stems, which is located under the stumps and roots of trees. Pregnancy lasts an average of 20 days.
Young individuals leave the nest on the 20th day after birth. During the season, the shrew leaves 3 litters, and in the first there are 8-10 cubs, and in the last - only 3-4. The second litter appears after the grown-up individuals from the first leave the nest.
Lifestyle
shrews active throughout the year, and they endure the winter without plunging into a long hibernation. During the day, they spend most of their activity at dusk and at night.
Even though the animal is in genus, it does not build holes on its own, but uses ready-made labyrinths of underground animals, moles, natural cracks and dips in the ground.
They can trample passages under the forest floor and in the thickness of the snow (passage diameter 2 cm).
IN winter time they practically do not rise from under the snow, but if it is impossible to dig out insect larvae from the frozen soil, they move along the surface in search of plant seeds.
REFERENCE! In the absence of food, it dies in a few hours.
The shrew shrew has a very high metabolic rate - it eats up to 150% of its body weight per day, 15 grams of animal food or 20 grams of fish.
The frequency of eating depends on the size - the smaller the animal, the more often you need to eat. For example, a tiny shrew must eat 78 times a day!
During the winter, the amount of seeds and plant foods in the diet increases. There are known cases of creating stocks at this time from earthworms.
There are also innate protective processes for a successful wintering - in the autumn period there is a serious decrease in body weight and volume, which includes all internal organs, including the brain.
In the spring, before the onset of the breeding season, the body returns to normal size.
Photo
See below: shrew photo
Distinctive features from other rodents
shrew often confused with mice. Their main differences are small eyes, a long elongated muzzle with inconspicuous ears, and a reddish tint of teeth.
Benefit and harm
Shrews are predominantly insectivorous animals, and therefore usually do not damage agricultural plantings.
However, they may V winter period sneak into houses, barns, sheds to search for food, both vegetable (seeds), as well as sleeping insect larvae.
Some farmers believe the shrew is the reason for the appearance of a large number of minks on lawns or beds. But this animal cannot dig them on its own, because the paws are not designed for digging!
At the same time, thanks to the constant search for food, the animal destroys a huge number of pests, including wintering in the litter and in top layer soil.
Her basic diet are worms, larvae, spiders, wood lice, including pests such as slugs, Maybugs, bears, leaf beetles, weevils, moth caterpillars and scoops.
In case of severe hunger, the shrew attacks ground beetles or small mice.
IMPORTANT! If the desire to get rid of the animal on the site still exceeds the benefits that it can bring, it is best to use non-fatal methods - for example, ultrasonic repellers.
Large farmland does more good than harm. But small gardens can suffer from this animal. We have prepared an article about being in the garden and suburban area.
Conclusion
shrews- These are small animals from the family of shrews. They are common in many parts of the world, in Russia they live almost throughout the entire territory. They do not build their moves using ready-made underground passages of other animals.
Feeds on insects and their larvae are of great benefit household and farming. The harvest can only be touched in the event of a severe shortage of food.
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The common shrew is a small mammal of the shrew family.
This animal is also known as an ordinary shrew, or forest shrew.
Appearance
Body length 5 - 8 cm, tail length 6.5 cm, weight 4 - 16 grams. Like other shrews, the muzzle of the shrew is strongly elongated and resembles a proboscis.
For the rest of appearance the shrew resembles mice, although it is not related to them. The fur of this animal is short, black or dark brown, with a rusty tinge on the sides. It got its name because of the brown teeth, which sometimes even have a reddish tint.
The shrews have ears, but they are so small that they are almost indistinguishable in the thick hairline. A structural feature of the shrew is its brain. It is one tenth of the body weight. This is a very large proportion - more than the brain-to-body ratio of humans and dolphins.
common shrew photo
True, the shrew cannot be called especially brilliant, but it is a rather smart animal, like most predators.
Habitat
Most shrews are found in the North and Western Europe, including the northern and northwestern regions of Russia. These animals settle in a variety of places, but prefer shade and moist soil. They live in parks, forests, sometimes in swamps; The shrew usually avoids open places.
Like mice, shrews are often found in residential buildings in rural areas, where they run especially often in autumn and winter. At the same time, they endure rather harsh conditions and are able to survive the winter without falling into a long hibernation.
common shrew on a hummock photo
It is curious that in especially severe winters, shrews live in abundant snowdrifts, while in the open they can die.
Nutrition
As already mentioned, shrews look like small rodents. However, their diet is completely different. They are ferocious predators and feed not only on small living creatures - worms, insects and their larvae, but also attack much larger animals - mice and other rodents, frogs.
Shrews spend almost their entire lives in search of food, which is explained by their extremely high metabolism; their body temperature is much higher than that of most other mammals, and is 40 degrees. In winter, shrews look for hibernating insects under the snow.
delicacy shrew photo
In houses, they climb into cellars and cellars, but they do not eat the food stored in them - they hunt insects there. Small amounts of shrews eat the seeds of spruces and pines, linden nuts and other plant foods; this is most often the case in winter when animal food is scarce.
reproduction
Shrews start breeding in March and continue throughout the warm period. During the year they can give several litters, each of which has 7 - 8 cubs. "Mice" are helpless, naked and blind, but they grow very quickly and at the age of one month they begin to hunt. At the same time, shrews build nests from stems and roots, the floor is lined with moss. Nests are located in the soil, old stumps or abandoned mouse holes.
One of the most common Siberian shrews.
Description of the signs . The shrew is of medium size, more massive, coarse build than the average shrew. Body length with head 48-72; tail length 20-40, foot length 9-12, weight 3-9 g. Wide frontal part of the head without a sharp narrowing in the eye area, passes into a wide, relatively short proboscis. The length of the tail and the color of the fur vary widely. The most short-tailed shrews are confined to the northern part of the range. In the northern parts of the range, the coloration is sharply two-tone, in the southern parts it approaches a single color. Overwintered and young animals differ significantly in coloration. Overwintered animals living in the tundra zone in the north of Central and Eastern Siberia have a dark saddle on their backs, sharply separated from the light sides and lower region. The color of the summer fur saddle varies from pale fawn-rusty to intense coffee-brown. More often there are individuals with a dark color of saddlecloth. The color of the sides and ventral region varies from white to silvery-grayish-white. The tail is sharply two-tone: dark above to match the back, grayish-white below. Winter fur is fluffier, longer and darker than summer fur. The color of saddlecloth varies from light brownish with rusty-yellow hues of varying intensity to brilliant black-brown. The underside is painted in lighter colors. In the coloration of young animals, geographical variability is well expressed. In some populations, a slightly pronounced blackness of color is observed, in others, the dark color of the back gradually turns into lighter sides and a whitish color of the underside.
Condylobasal length of the skull 15.7-18.3, on average 17.3 mm; the greatest width is 8.0-9.5, on average 8.8 mm; the greatest height is 4.8-6.2, on average 6.0 mm. Skull with a relatively short and wide facial part (the length of the brain capsule is approximately equal to the length of the facial part of the skull). The upper intermediate teeth are pointed, tightly closed, massive; the longitudinal diameter of the bases of the crowns of the upper intermediate teeth is less than their height (difference from the average shrew). The second upper intermediate tooth is higher than the first and third.
C o d n y ev i d y. It differs from the common shrew in the largest size of the 2nd intermediate tooth; from the flat-headed and middle shrews - with a relatively narrow and very contrasting "saddle" on the back; from the lesser and Far Eastern shrews, which are not found in Evenkia, also in larger sizes; from the even-toothed shrew - also with a light belly; from the clawed shrew - also with short claws.
Spreading. The Arctic shrew is the most widespread insectivorous species in the world fauna. The range of this species covers North-Eastern Europe, Asia south to China and Mongolia, North America to the headwaters of the river Mississippi. In Russia - from the river. Pechora to the east to Chukotka inclusive. In Siberia, apparently, it is found everywhere.
Of the 5 subspecies described in Russia, the southeastern part of Evenkia is inhabited by sorex arcticus buxtoni .
B i o t o p s. Within a vast range, it inhabits biotopes with a wide variety of natural conditions in the arctic tundra, forest tundra, plain and mountain taiga, forest-steppe and steppe landscapes. Each of these and other divisions includes many more biotopes with their own nuances of the natural environment. All this indicates a high ecological plasticity of the species, its ability to live in a wide variety of environments. natural conditions. Despite such a variety of biotopes it occupies, the arctic shrew everywhere prefers to populate areas with forest vegetation, of which it prefers floodplain willow forests and overgrown clearings.
Nutrition. It feeds on small invertebrates, mainly various insects. The aspect of food varies significantly depending on the landscape in which the animals live. The main food is various beetles (mainly medium-sized ground beetles). The daily diet of the animal is 170% in relation to body weight. In all regions, the basis of the diet is beetles (21.4-75.0%). Earthworms eat less frequently.
C a m n o d e n and e. It usually breeds in summer, brings 3-4 litters a year. The number of embryos is from 5 to 11. Profitable females participate in reproduction.
The tiny shrew is a mammal of the shrew family of the insectivore order, similar to a small mouse. The tiny animal got its name from the word "brown", since the tops of the creature's teeth really differ in this unusual color.
Habitat
You can meet the shrew almost everywhere, often more than three species of these animals live simultaneously in the same area. For example, in the Moscow region there are as many as six varieties of shrews: common shrew, small and medium, tiny, even-toothed and shrew.
Even-toothed are found along backwaters and river banks, just like the common water shrew, they are great lovers of dampness. The average and tiny shrews are among the most rare species preferring coniferous, taiga forests. The lesser shrew and the common shrew settle in open areas - in the steppe, meadows, and light forests.
The shrew is unpretentious in terms of comfortable living conditions, but the abundance of food all year round for her - a necessary condition. Traveling over considerable distances in search of food for a small animal is not possible, and it is not able to withstand more than 3-4 hours without food.
Characteristic
The tiny shrew is one of the smallest insectivorous creatures in Russia and Europe. The size of an adult, together with the tail, is 6-7 cm, and the weight does not exceed five grams. The description of the tiny shrew is more correct to start with silky soft coffee-colored fur on the back, turning into a light fluff on the stomach. The tail, which is a little more than half the length of the shrew's body, is also two-colored. Paws are not covered with fur.
In summer, the color of the beast fades slightly, in winter it becomes more saturated. The ears of the animal are small, but the hearing is very well developed, as is the sense of touch and instinct. The elongated head ends with a nose-proboscis with bristling vibrissae (long whiskers).
Shrews do not live more than a year and a half, and about a fifth of this short life their breeding season lasts. Unlike most animals, the female's gestation period is not strictly fixed. The cubs will be born healthy in 18 and 28 days. The average number of babies for one offspring is about five, but sometimes 8. During her life, an adult female brings from 1 to two litters.
Lifestyle
The high vitality of the tiny shrew is due to the constant search for food. At least 70 times during the day, the activity of the animal freezes for a short time - a 10-15-minute sleep. Then the bustle resumes.
To maintain a normal life, the tiny shrew must consume an amount of food twice its body weight. In the warm season, intensive searches for food are carried out throughout the entire territory that the animal is able to cover in short dashes: on trees, in the soil. In winter, searches are transferred exclusively to the soil, and under the snow the animal orientates itself as well as in open space.
Shrews willingly eat all living things that smaller size themselves, but in the cold season they do not disdain the waste products of their own kind and other, large animals. In a particularly hungry time, adult shrews calmly include cubs of their fellow tribesmen in their diet.
In winter, shrews do not hibernate, but it is almost impossible to see them on the surface of the snow cover. Due to the overly bright coloring, animals leave the snowy territories only in situations of emergency and when they are very hungry. This prudence could be called superfluous, since the strong specific smell of the animal discourages predators from hunting, if it were not for owls - the only representatives of the predatory fauna who are not so whimsical.
Another interesting fact is that the tiny shrew at any time of the year retains the most high temperature bodies in comparison with all mammals of the planet - from 40 0 С.
Most of all animals of this species live in the taiga - an average of 350-400 shrews per 1 ha, but in other areas of their habitat, the existence of tiny creatures is under threat. In the Murmansk region, the tiny shrew is listed in the Red Book.
In the forest-tundra, it dominates over all shrews, and in the typical tundra it is the only representative of the shrew genus, but its numbers there are extremely low.
The upperparts are gray, almost without a brownish tint. Unlike the average shrew, the tail is without a tassel.
The shrew is of medium size: in overwintered animals, the body length is 70-80 mm, body weight is 7.5-10.2 g. The color of the fur of overwintered individuals is bright, two-tone. The dark saddlecloth is very well defined on the back. The sides and belly are white or light gray. In young animals, the saddle, as a rule, is less distinct, their coloration resembles young common shrews.
In the forest-tundra, it dominates over all shrews, and in the typical tundra it is the only representative of the shrew genus, but its numbers there are extremely low. The basis of nutrition is beetles. In the northernmost parts of the range, their role is greatest. It also eats other invertebrates.
Inhabits Kamchatka, Chukotka and the Northern Kuriles in floodplain forests, shrub tundra, among mountain elfin.