The giant mole rat is a fairly rare endemic animal that lives underground. Spalax giganteus is the Latin name for a mammal that is often confused with a mole, although it is many times larger than this insectivore. A secretive lifestyle and a small population prevent a full study of the nature of the animal.
Origin of the species and description
The giant representative of the mole rat family belongs to burrowing rodents, along with zokors and a bamboo rat. It is believed that in the detachment of murines this is the oldest branch. Previously, it was assumed that each species of this family evolved and adapted to life underground on its own, but later studies proved their relationship and combined them into one monophyletic group.
Representatives of mole rats were found in the early Pliocene from the western regions of Ukraine, to the north of the Volga region, in the Ciscaucasia, in the Trans-Urals. Cytogenetic studies confirmed the fractional system of the genus Spalax Güldenstaedt — mole rats. No fossils of the giant mole rat have been found before the beginning of the Halocene.
Video: Giant mole rat
Previously, this type of mole rat was considered a subspecies of the common one, despite significant differences in color and size. Isolation into separate subgenera of these animals, according to the holes on the back of the head, is untenable. Studies have shown that the small mole rat does not have holes, but only small pits and their number may vary. More often there are two of them, but sometimes one or three, the giant fossa has one.
The genus of mole rats includes, in addition to the giant, four more species:
In addition, there is a genus of small mole rats, which includes small, Palestinian and non-ring. Animals have differences in appearance and size, as well as in habitat, their lifestyle is similar. The animals are actually blind, there are not even traces of reduced eyes left, they are hidden under the skin.
Appearance and features
These mouse-like rodents are all adapted to the underground lifestyle. A powerful bullet-shaped body, with a conical head tapering towards the nose, almost does not have a marked transition in the form of a neck. As unnecessary, the auricles are not developed, and the tail is almost not expressed.
Stripes of coarse bristles run from the ears to the nose, they play the role of vibrissae, participating in the process of touch. There are also vibrissae on the abdomen, forehead, in the back half of the body. The nose is large, leathery, with folds that cover the nostrils, protecting them from soil particles when digging.
The lips seem to flow around the front incisors, which stick out strongly from the mouth. Also, on the upper and lower jaws, there are three molars on each side. The incisors are wide and unusually large, with a large gap between them. The wide front part has a shorter, compared to other related species, nasal bones and palate, and the back of the head is placed lower. The lips open the entrance to the oral cavity only during eating.
The paws of the rodent are short, five-fingered, the hind legs are slightly larger than the front ones, and the claws are small. Paws, unlike many other burrowing animals, are poorly developed. The mammal crawls along the burrows. This is the largest member of the family, thick and slightly elongated, like a mutaka sofa cushion, it can reach a weight of 700-1000 g. The length of the rodent reaches 30 cm, and the length of the foot of the hind leg is almost 37 mm.
Short, dense fur without down. It has a fawn, ocher color that brightens with age, especially on the top of the head. The belly is usually darker in color with shades of grey. The short length of the hairline allows the animal to move freely in its labyrinths, both forward and backward.
Interesting fact: the hair of the mole rat lies equally well from head to tail, and in the opposite direction, this allows him to move well “glide” inside the hole head first and backwards.
Where does the giant mole rat live?
The distribution area of this endemic rodent with an underground lifestyle is small.
It is found:
- in semi-desert regions in the north-east of Ciscaucasia;
- between the lower reaches of the Terek and Kuma rivers;
- in the lower reaches of the Sulak;
- south of Makhachkala to Gudermes.
To the north of his settlements reach:
- to the southern lands of the Astrakhan region;
- south of Kalmykia.
There are small and isolated settlements:
- east of the Ural River;
- in the Kara-Agacha region;
- in the vicinity of the rivers Temir, Emba, Wil;
- in the northeast of the Guryev region;
- in the west of the Atyubinsk region.
The animal prefers sandy and clayey semi-deserts, but settles in places where there is moisture: in floodplains of rivers , in bearded and lake-feather grass steppes and forest plantations, also found in forest-steppes. Likes chestnut soils. The animal can be seen at an altitude of 1400-2400 m above sea level. m., more often at an altitude of 1500-1600 m.
Interesting fact: Observations of a released mole rat in an area where no other individuals were found showed that in four months he built 284 groups.
Where a group of individuals lives, about 15% of the area is covered with heaps of earth. In spring, mole rats begin to lay new feeding passages, which they use all summer. Moving along them, the rodent grabs the germinating roots, and drags the whole plant behind them. In autumn, they again begin to actively dig passages, but these works are not so noticeable from above. The animals expand the passages of the lower tier, nesting chambers, but they do not push the soil out, but clog the feeding passages with them.
Rodents also make seasonal movements. In winter, they move closer to forest belts. There is more snow, the ground is protected from the cold and does not freeze as much, and the dense root system is a source of food. In spring, they move closer to fields with perennial grasses.
Interesting fact: Mole rats dig holes in sandy soil at a speed of about 2.5 cm/hour or 850 mm in 20 minutes, during this time, volume emissions is 25,000 cm3.
What does the giant mole rat eat?
This mammal is a rodent, respectively, it feeds on all the roots of plants that it finds on its way. They not only gnaw on roots and tubers, bulbs, but can also drag the plant itself into the hole. In addition, these animals, like many other rodents, stock up for the winter. In their pantries you can find several kilograms of corms, rhizomes, etc.
In the menu of mole rats there are up to 40 names of different plants, preference is given to Asteraceae, legumes, labiales, moreover, the rodent does not drag anything into its mouth, but chooses succulent cultivated species, which causes great harm to agriculture, especially it worries private traders. It is they who, tirelessly, dig, loosen, harrow, water, making the soil supple, and the plants tastier and juicier. So the mole rats tend to gardens and household plots of summer residents.
From wild plants, his favorite food is the roots of chicory, wheatgrass, wormwood, hyposphila (kachima), bony hair, juzgun. At the end of summer and autumn, the rodent, harvesting the roots, eats the upper part. In vegetable gardens damages potatoes, carrots, beets, turnips. The animals are especially fond of bulbous plants, where they grow, in the habitats of this animal, accumulations of rodents always form.
Interesting fact: 15 kg of vegetables and up to 18 kg of potatoes were found in pantries of giant mole rats .
In the summer, a rodent eats food per day, equal in volume to its own weight — about 700. If he also ate in winter, then even significant stocks of storerooms would be enough for him for barely a month. So far, its life in the winter period has been little studied. Obviously, part of the energy reserves is consumed from subcutaneous fat, part of the food is received from pantries, it is possible that animals continue to extract roots for food.
Character and lifestyle features
Mole rats dig long and branched burrows at a depth of 20-80 cm. More often, feeding passages are arranged in two tiers, crawling along them, the animal gets food. From these tunnels, steep passages lead down into the depths to a lower tier. A network of tunnels, consisting of main passages with exits from sidings, with pantries, converges to the main highway, where a nest (sometimes 2-3) and several pantry chambers (3-15 pieces) with food supplies and latrines are located.
Multi-tiered galleries are a complex structure, if you put all the passages into one chain, then their length can be a kilometer, and the nesting chamber is hidden at a depth of 120-320 cm, the passages can be located at a depth of up to three meters. The pantries of rodents look like tunnel chambers, “sealed” on both sides with earth.
Usually underground animals dig their passages with the help of their paws, but mole rats have their own technology, the entire body of the rodent is adapted to it. He makes his way with the help of long incisors, does not dig, but bites into the soil. That is why his lips, equipped with folds, cover his mouth not only from above and below, but also between the upper and lower incisors, so that the earth does not fall while digging passages.
They push the soil out of the hole with their heads . Quite large earthen mounds form near the entrance, they mask and close the entrance, and a new one is dug out next to it. At the base, a pile of earth has a diameter of half a meter or more.
When it becomes difficult to push out the soil, the rodent clogs the soil with earth, and a new one digs at the end of the move and makes another mound. Thus, in one copy, with its system of moves, about 250 mounds of earth appear. They are placed from the entrance at a distance of 10 to 75 cm, and between the piles the distance is 20-100 cm.
Mole rats are solitary in nature and each adult has its own burrow with a network of tunnels and storerooms. Traces of his habitation can be seen not only in the “molehills”, but also in withered plants, the roots of which he ate, or even in the absence of individual specimens, which he dragged into the hole. Moulting in these blind rodents takes place twice. First time in spring months, second time in August-October.
Social Structure and Reproduction
A family of mole rats, always living next door to each other, in one area can dig passages over an area of several hectares. By the end of winter, at the coldest and most hungry time for these animals, the testes of males reach the largest mass and size.
By March, the females also mature eggs. Each individual, occupying a separate system of burrows, clogs summer feeding passages for the winter. By this time, the topsoil is still frozen and each mole rat is isolated. But they have well developed all the senses, except for vision.
To attract attention, they make grunting sounds and specific smells. But even with excellent hearing and sense of smell, it remains a mystery how they manage to overcome 10-15 or even more meters in the frozen ground between neighboring holes. How this happens is unknown, in winter no heaps of earth appear on the surface, but about half of the females successfully complete their dates and by the end of March — at the beginning of April they bring offspring.
For a year, the animals have offspring once. In the litter, as a rule, there are from two to four naked and helpless babies, weighing 5 g each. While breastfeeding, the babies are in the nest, by one and a half months they already move freely along the tunnel passages. With the onset of autumn, young people leave their parental holes and start building their own network of underground labyrinths. In winter, the activity of animals decreases, and they also consume much less food.
Interesting fact: Observations have shown that on a virgin area of one hectare, in four years, mammals have built almost 3.5 thousand .heaps of earth. Their volume was 13 cubic meters.
Natural enemies of giant mole rats
Stealthy animals leading underground way of life, has almost no enemies in nature. Young animals are most often attacked during relocation. They can be hunted by foxes, large birds of prey, animals of the weasel family.
An interesting fact: a mole rat, accidentally appearing on the surface of the earth, first freezes, obviously trying to orient itself, and then starts spinning in place, moving backwards, after which it tries to burrow underground as soon as possible.
Those the passages and burrows that the rodents left are occupied by predatory animals: dressings, weasels, light and black ferrets.
Interesting fact: In the autumn, the light ferret often goes on the hunt for the mole rat. Through unclosed fodder holes, he penetrates into the labyrinth of passages, moves along them, finds the owner and kills, eats prey, and occupies the hole. At other times of the year, this predator feeds on voles, ground squirrels, mice.
Segments of feeding passages that are not used by a blind digger are inhabited by gophers, voles, hamsters.
Mole rats are harmed by human agrarian activity, plowing of meadows and steppes. But since this species often lives in semi-desert areas that are not promising for agriculture, there is no danger of extermination of rodents by humans in these regions. Burrowing dogs can hunt the animal, and cats can hunt young migratory rodents.
In the gardens, people use different methods to scare away these animals, as well as traps and traps. But since rodents do not come to the surface, this kind of trapping is not effective. The best way — vibrating and ultrasonic repellers.
Population and species status
A giant mole rat takes a territory of approximately 37 thousand hectares, this is a relatively large range of habitat for the endemic, and the sandy areas where it lives are not of interest for agriculture, which ensures the stability of the population.
Within the range, it occurs in separate settlements. Data on the number of animals are unreliable, often contradict each other. In the 60s of the last century, the livestock was estimated at 25 thousand individuals. Starting from the 70s, the numbers began to decline sharply, reaching 2-3 individuals per 10,000 hectares in the 80s.
In Dagestan (the main region of habitat), their number in the early 80s amounted to no more than 1200 copies, and according to other sources, by 88 & # 8212; 10 thousand individuals. The decrease is due to human agricultural activities. In those places where such work is not carried out, the number of mole rats grew.
In later years, no analysis was carried out, but human anthropogenic activity has significantly decreased, which should have led to an increase in the animal population. At the moment, the demographic trend is assessed as stable.
Protection of giant mole rats
The narrowing of the habitat of these rodents can occur due to salinization of the soil, when grazing livestock, and when plowing land. This can force animals into more unfavorable conditions and lead to a decrease in their number.
In the International Red Book, the giant mole rat is rated as a vulnerable species. The Red Book of the Russian Federation noted that this is a rare species of the third category. The mole rat is found in the protected lands of Dagestan and Chechnya (Stepnoy and Parabochevsky reserve on the territory of the Shelkovsky district, Yangiyurtovsky reserve – Kizilyurtovsky district, Hamamatyurtovsky and Agrakhansky reserve – Babayurtovsky district)
At present, the narrowing range and abundance recorded on the territory of Chechnya, almost to the point of extinction, on the right bank of the Terek, in the territory of Dagestan (north of the village of Krainovka, Novo-Terechnoe). But for the rest of the territory of Dagestan, the narrowing of the range does not occur. The vulnerability of mole rats is explained by low reproduction.
To restore and preserve the species, it is necessary to reduce the impact of human activities, where the giant mole rat lives, and create additional protected areas. Constant monitoring will allow you to monitor the change in the population. Measures are needed to restore the population of these animals, in particular, the use of reintroduction.