Apodemus agrarius Pallas. - Black-Striped Field Mouse.
Systematic position.Class Mammalia, order Rodentia, family Muridae, genus Apodemus. In the territory of the Former Soviet Union, not more than 4-5 subspecies are known.
Biological group.Pest rodents.
Morphology and biology.Body length reaches 126 mm, tail length reaches 90 mm (about 70% of body length), sole length reaches 28 mm. Ears and eyes are relatively small. Coloration of the upper part is gray-ocherous, with rusty tint; black stripe along spine. Body ventrum is grayish. There are no spots or stripes on the chest between forefeet. Diploid chromosome set is 48. Inhabits zones of mixed and broad-leaved forests, forest steppes, and steppes. In the mountains of the same zone belts, A. agrarius inhabits areas 1000 m above sea level in Carpathians and 2000 m in Altai. It penetrates into taiga zone and desert steppes along river valleys and via agrocenoses. It prefers open and well-moistened biotopes with diverse grass and shrub vegetation. It avoids massive forests and arid regions. A. agrarius colonizes fields of grain and other agricultural crops, forest belts, gardens and vegetable gardens. It often occurs in abandoned lands, boundary strips, gullies and ravines. In winter, it migrates to haystacks and ricks, storehouses and dwellings.
Distribution.This is a wide-spread species, occurring in the majority of Eastern Europe, in the eastern part of Mongolia, in Northeast China, and in Korea. Within the former USSR, it inhabits the entire European part (except Crimea and regions to the north of St. Petersburg), North and East Kazakhstan (Zaisan and Alakol depressions), North Kirghizia, South and Middle Ural, and southern regions of Western Siberia to Lake Baikal. An isolated part of the area includes the south Far East, i.e., Amur area (middle reaches of the river Amur) and Primorskii area (from Khabarovsk to Vladivostok). During recent decades, the area of pest distribution has been significantly extended. In the Far East, this occurred because of deforestation and substitution of forests by agrocenoses. In Northern Kazakhstan, on the left steppe bank of the Volga River, and in Ukraine, this occurred following the development of virgin and long-fallow lands. In southern regions, this occurred following the development of irrigation systems. Within the main area, however, there are places where this species is totally absent, creating a so-called .lace. of the area. For example, steppe zones in the south of the European part, some parts of Moscow, Tula, Kaluga, and Smolensk Regions, and some parts of Leningrad and Vologda Regions (Vepsa hills).
Ecology.Circadian activity changes during a given year; it is nocturnal in summer, diurnal and nocturnal in autumn, and mainly diurnal in winter. A. agrarius is very mobile, migrating for long distances during a day; individual range reaches hundreds and thousands of square meters. Burrows are simple, with 1-2 entrances; nesting chamber is situated at a shallow depth. In the Far East, where this species colonizes bogs, dams, and rice checkrows, the burrows are complicated and resemble .colonies. of field mice. In moistened biotopes, where fossorial activity is impossible, nests are constructed on the soil surface or in shrubs. It willingly colonizes drifts of stones, which are created along fields after field clearing. Its diet varies according to season and food availability; green parts of plants prevail in spring and early summer, seeds and berries in autumn and winter. Insects comprise a large portion of the diet. Winter stores are small. The intensity of reproduction is very high; reproductive period lasts about 9 months, from early spring until late autumn; in a given year there are 3-4 (to 5) broods with 4-9 (6 on average) young mice in a brood. In winter, the process of reproduction continues, but not intensively, in haystacks and ricks. As a result, population numbers may become high. Factors limiting the number of field mice are frequent torrential rains during a warm season, early (before snow precipitation) soil freezing, and small predators.
Economic significance.This species is one of the most common pests of grain crops. It also causes harm to vegetable crops near towns and other settlements, i.e., potato, carrot, and red beet. In melon fields, it gnaws seeds, damaging melons and watermelons. In arboretums, it destroys seeds of valuable tree varieties, gnaws bark of young shoots of broad-leaved trees and berry bushes. In warehouses, this animal pollutes and destroys stored agricultural products. Natural vector for pathogens like tularemia, leptospirosis, hemorrhagic fever and other dangerous diseases. Control measures are the same as for other Muridae species, including quality (without losses) harvest, removal of plant stores, haystacks and ricks from fields, and poison baits in fields and warehouses where trails of mice are found.
Related references:Gromov I.M., Erbaeva M.A. 1995. Mammals of the fauna of Russia and adjacent territories. Leporids and Rodents. Eds. A.A.Aristov, G.I.Baranova (Keys to fauna of Russia, published by Zoological Institute of RAS. Issue 167). Saint-Petersburg, ZIN RAN. 552 p. (in Russian).
Karaseva E.V. 1979. Apodemus agrarius Pallas, 1771 - Field Mouse. In: Medicine Teriology. Ed. V.V. Kucheruk. Moscow: Nauka. P.194-203 (in Russian).
Kulik I.L. 1971. Ecological structure of field mice population. In: Fauna and ecology of rodents. Ed. V.V. Kucheruk et al. Moscow: Moscow University. Issue 10. P.187-198 (in Russian).
Plyater-Plokhinskii K.A. 1936. To the biology and ecology of Apodemus agrarius mantschuricus Thom and the dynamic of its reproduction. Vestnik Dalnevostochnogo filiala AN SSSR 19. P.93-111 (in Russian).
Sviridenko P.A. 1949. About distribution, reproduction and death of field mouse. Proceedings of Institute of Zoologyof AS of the USSR. V.2. P.18-47 (in Russian).
Tikhonova G.N., Karaseva E.V., Bogomolov P.L. 1992. The main changes of field mouse area in Soviet Union for last 30-40 years. In: Synanthropic rodents and regulation of their numbers. Moscow: Nauka. P.301-322 (in Russian).
Shkilev V.V. 1960. The peculiarities of changes in field mice numbers in Primorski Krai. News of Irkutsk Antiplague Institute of Siberia and the Far East 18. P.171-195 (in Russian).