Changes in population. Average gopher inherent fluctuations in the number of duration of a few tens of years, periods of depression, which in some parts of the range are manifested in different ways.
Our long-term steady-state studies, combined with a route studies have shown that in the Betpak Dala after 1950 there was a sharp increase in the number of ground squirrels, while in 1938 it was very low (Beloslyudov, 1948). Low number of this animal in the 30's, is one of the reasons for not including it in the "core fauna" mammals Betpak Dala.
Pointing to cause sharp fluctuations in the size of the middle ground squirrel Betpak Dale, S. Sokolov (1956) Characteristics of climatic events Karsakpaya district for 23 years. It turned out that in the period from 1929 to 1936. precipitation fell out a little. This was, apparently, one of the causes of depression in the ground squirrel population 20 and 30 years. Later observed wet years (1946, 1947, 1949 and the first half of 1950), in connection with which there was a sharp increase in the number of ground squirrels (40 holes per 1 ha in 1950), especially in the central part Betpak Dala ( Cooper, 1956).
Decline of the middle ground squirrel in central Betpak Dala pointed us in the years 1960-1961., When the most favorable habitats for a density of no more than 10 holes, and the number of animals varied from two to three individuals per 1 ha. And in this case the cause of decline in the number of rodents were the preceding years of drought that affected their reproduction.
Fluctuations in the number of ground squirrel in southern Balkhash characterized by the following data. In 1930 and later its numbers in the valley. Or was negligible (Belyaev, 1955), animals are found only in the vicinity of the village. Chilik (one settlement in dozens normal). Since about 1945 the number of them began to grow, and now this animal is common in the valley. Or. In 1941, the north of the River. Kurt (middle course) no sign of habitation there gophers were noted, while in 1950 their average density was normal at 1 20-120 ha. Much the same was observed in the Zaisan Valley in 1950 compared to previous years. There from the beginning of the century up to 1942 high numbers of rodents was observed that in the south-western corner of the Zaisan Nord (at the beginning of the century and in 1929), then along the eastern shores of the lake (in 1915 and 1942.). In this case, every 13-15 years Gophers changed their habitat, which is apparently explained by the periodic changes of the climate in the region (Bazhenov, 1953).
Dynamics of average number of ground squirrels depends to some extent on the activity of predators and epizootic. However, these factors can not be proven because they are concrete examples of poor knowledge. Excluding the impact of these factors, the movement number of gophers with a year only one crop will depend on the intensity of reproduction – the percentage of females participating in reproduction, and size of offspring. Here we have in mind that the sex ratio of gophers close one to one.
The course of this animal breeding affect release dates it from hibernation, the meteorological conditions during this period and the conditions nazhirovki previous year. Waking up to normal for this time of, the friendly and warm spring is accompanied by increased reproduction. At the same rut gophers is actively involved in the reproduction of the maximum number of mature females. Late release dates of females from hibernation negative impact on the course of propagation. For example, a large proholostanie females (85.4%) in Betpak-Dala in 1955 was due to the relatively late release them from their slumber. Meteorological conditions during waking ground squirrels have a significant impact on the nature of reproduction. Nevesennie early frosts or particularly sharp fall in temperature and snowfall forced the animals for a long time to sit in holes, extending the terms of their reproduction. However, the period of awakening and mating periods of gopher take less protracted, in what could be seen at the same time studying it and the yellow ground squirrel in southern Balkhash. Therefore, the effect of weather conditions in early spring to reproduction middle ground squirrel is relatively weak.
With regard to biological factors of the previous year (nazhirovki conditions), the effect on their breeding patterns and the size of this animal can be traced quite clearly. For example, the summer of 1954 in South Lake Balkhash (left bank of the Ili) characterized by an abundance of green vegetation. Gophers were able to accumulate a sufficient amount of fat, leading to a simultaneous hibernation individuals of all age groups. In the spring of 1955 strength rodents was high due to the release of their tight-knit out of hibernation.
Average ground squirrel is one of pests of crops and pastures especially since it is common in the desert, semi-desert and mountain areas with animal husbandry sector.
In the central regions of the desert Betpak Dala it eats plants, which are a valuable food for wild ungulates (antelope, gazelle) and farm animals. Daily demand for feed, one animal is about 150 Mr. Per month, one gopher eats more than 4.5 kg green mass. With an average population density of six animals per 1 hectare green weight loss will be more than 27 kg per month for each hectare of pasture. In some areas, the population density after settling profit reaches 10-12 animals per 1 ha. In this case, pasture herbage has a very depressed character, and squirrels are becoming serious competitors grazing sheep, as well as Saiga and gazelle.
In the semi-arid zone (upper Sarysu, Kazakh Plateau), this hurts a gopher in pastures and on cereal crops. Rodents are marked on the newly reclaimed areas of virgin land – in the fields of wheat in the tillering stage.
On average, an area of 1 hectare planting estimated eight holes around which vegetation has been eaten or trampled ground squirrels completely. Such ogolygnye area is 80-100 n2. The loss of the crop has reached the big size – about 6-8%.
Due to the large size of the middle ground squirrel has been a major pest of pastures and crops in the eastern part of the foothill zone of the Almaty region. Yuri Afanasiev (1960) refers to reports of local residents that in 1952 completely destroyed the squirrels corn shoots 2 ha near the village. Karazhuty. It was produced 15 animals. There were also complaints about the damage caused by these ground squirrels gardens. According to research by the same author, on pastures in spring average gopher destroying germs splendens, ebelek, Kokpek, which are the main and almost the only food of cattle. The loss of green fodder was more than 27 kg a month in the area of 1 hectare pastures. Causing even more damage to the gopher alfalfa, where the population density of animals is much higher than in areas of virgin land. Normal around here almost all the young shoots are eaten within 5.4 m
Like other rodents – burrowing, their digging activity, these squirrels are constantly changing the surface layer of soil. Relocation of the soil surface from the lower horizons of salt-contributing to the deterioration of its quality and is a gradual replacement of the original vegetation over halophyte. This side of the ground squirrel is especially evident in areas with a high density of a normal distribution, in areas with sandy loam or loamy soils. In the foothills, as well as in the desert Betpak Dala dominated gravel soil, soil-forming role of the middle ground squirrel expressed rather poorly.
This animal – Minor fur look. Produced within the East-Kazakhstan, Almaty and Taldykorgan regions of Kazakhstan. During the period from 1932 to 1965. on average for the fishing season caught about 67,000 animals. When the purchase price by 6 kopecks. for top-notch normal skin total harvested in one year is about furs 4000 rubles.
To catch this type of ground squirrel traps used factory production (№ 0 and 1). Depending on the means of transportation, as well as the population density of animals each hunter has from 50 to 150 traps. Catching made since the release of animals from hibernation before they molt and lasts for about 1.5-2 months, depending on the habitats of gophers. Quality furs depends not only on meeting deadlines for hunting, but also from the primary processing of skins, which consists of a series of operations, photography, drawing, drying (konservirovka), and degreasing. Initial processing of skins significantly increases the organization teams, consisting of hunters, men and women qualified semschits.
As a result of fishing ground squirrels also produces oil and meat, which, after appropriate processing can be employed for household needs.
Measures for the protection and reproduction medium gophers are not available, as these rodents are pests of crops and pastures. Destructive measures with the use of poisoned baits were conducted in several areas of the East Kazakhstan region. Sufficiently developed mechanical methods of extermination (catching traps).