Pests
Spalax microphthalamus Guldenstaedt. - Ukrainian Blind Mole-Rat.
Systematic position.
Class Mammalia, order Rodentia, family Spalacidae, genus Spalax. Geographical variability is poorly investigated. There is evidence that North-Caucasian form belongs possibly to an independent species.Biological group.
Pest rodents.Morphology and biology.
This is a highly specialized burrower with full adaptation to underground habitation. Body is elongated, cylindrical, with length up to 290 mm. Legs are shortened, length of hind sole is up to 30 mm. External ear remains as a small ridge hidden by fur, tail is reduced and hidden as well. Back is dark, ocherous-brown. Diploid chromosome set is 60-62. The Blind Mole-Rat occurs in plain steppes and forest-steppes. It inhabits gully slopes, places with the most fertile soil and abundant grass vegetation; in arable lands this animal inhabits boundaries between fields, perennial grasses sowings, pastures, hayfields, and vegetable gardens. It prefers relatively compressed soils, avoids clay and loose, sandy soils.Distribution.
From the river Dnieper (except lower parts of the left bank) in the west to the river Volga and Ciscaucasia (except southern parts of Krasnodar and Stavropol Territories) in the east. Northern limit of the area goes from Kiev - along the southern part of Chernigov Region - along the eastern parts of Kursk and Orel Regions - along the southern parts of Tula, Ryazan, and Tambov Regions, Republic of Mordovia, Penza and Ulyanovsk Regions. Southern limit of the area goes along the coast of the Azov Sea - along the south-western part of Krasnodar Territory - along the north-eastern part of Stavropol Territory, and further towards the river Volga, to the northern environs of Volgograd. South-eastern limit of the area is not established precisely. Distribution is extremely uneven and depends on the extent of development of gully net, i.e., on the availability of plots unsuitable for total plowing and the level of arable land cultivation in general. In southern part of the area, in connection with mass deforestation the Blind Mole-Rat inhabits pastures and meadows in mountains up to 1400-2200 m above sea level.Ecology.
Year-round activity. Blind mole-rat does not hibernate; as soil freezes, it goes into deeper part of burrow. Its digging activity is notably decreased in winter and increased sharply in spring, when 15-18 fresh mounds of earth appear in a day. Solitary lifestyle. Every Blind Mole Rat has its individual plot, which is usually not left. Burrows have a complicated construction and there is a whole system of underground tunnels and chambers used for special purposes. There are 2 main types of subterranean passages. The first ones are upper-level horizontal passages for underground search for food; they are flexuous and lie at depth of 10-15 cm. Their total length reaches 250 m and more, depending on many factors, such as sex and age of Blind Mole-Rats, periods of burrow usage, time of the year, relief, soil features, level of subsoil water, food supply. The second type is lower-level deep passages connecting 1 or 2 nesting chambers, 4-5 storerooms and .latrines. or short passages 10 to 15 cm in length, which are closed with earth plug as they are filled with feces. Both types of underground passages are connected with each other by 2 to 4 vertical corridors, their depth can reach 120-320 cm. Habitats of the Blind Mole-Rats are easily visible by traces of their digging activity, i.e., by mounds of excavated earth ("hills.) of different form and size. Sometimes there are hill aggregations produced on one plot for a long time and reaching a great size. The ration of Blind Mole Rat consists mainly of underground parts of plants, as well as of stems and leaves; the animals obtain them, without leaving burrows; they gnaw at roots and drag the whole plant into an underground passage. They make large stores for winter. Blind Mole Rat breeds once a year, having 2 to 6 young rats in a brood.Economic significance.
The Blind Mole Rat is a serious pest of field and garden crops, especially on perennial grass sowings, pastures and hayfields. Vegetation is destroyed by damage of root system. Also earth mounds make difficult or impossible to machine harvest forage grasses. Soil fertility is worsened markedly in Blind Mole Rat habitats because of excavation of large amounts of earth from under-ground (including maternal rock) onto surface. These field plots (.bald patches.) remain without vegetation for a long time. They are gradually covered with weeds and thereby decrease total yield and nutritive value of forage grasses. Can also significantly damage forest belts in regions with shelterbelt forest planting. During digging activity the roots of oak seedlings and other trees planted to protect fields from wind erosion are mechanically damaged and they are also stored, sometimes in great amounts. In connection with the Blind Mole Rat habitation the system of control measures is restricted to mechanical trapping. Breaking the system of underground passages with deep plowing is more effective to decrease population size. Epidemiologic significance of the Blind Mole Rat is small.Reference citations.
Dukelskaya N.M. 1932. The biology of Blind Mole Rat and testing different measures in its control. Proc. on Plant Protection. Series 4. Issue 2. 23-34 p. (In Russian)Gromov I.M., Erbaeva M.A. 1995. Mammals of the fauna of Russia and adjacent territories. In: Aristov A.A., Baranova G.I., editors. Leporids and Rodents. Saint Petersburg: ZIN RAN. 552 p. (In Russian)
Ognev S.I. 1947. Animals of the USSR and adjacent countries. Family Spalacidae. Moscow-Leningrad: Ac. Sc. USSR. V. 5: 558-641. (In Russian)
Puzachenko A.Yu., Vlasov A.A. 1993. Digging activity of Spalax microphtalamus (Rodentia, Spalacidae). Zool. Zhurnal, 72(11): 91-103. (In Russian)
Topachevskii V.A. 1969. Spalacidae. In: Bykhovskii B.E., editor. Series Fauna of the USSR. Mammalia. Leningrad: Nauka. V. 3(3): 248. (In Russian)