Stoat — Mustela erminea Linn. (in Kyrgyz: arys, kara-kuyruk)
The territory of Kyrgyzstan is inhabited by the Fergana subspecies, which differs from other forms found in the territory of the former Soviet Union by its lighter coloration of summer fur. However, this coloration is subject to significant variations among the Tien Shan stoats. For instance, we have observed body coloration in various individuals ranging from ochre-gray and light brown to chestnut. A small portion of individuals does not molt to white fur in winter, but only becomes slightly lighter during the cold season. In terms of size and quality of fur, Tien Shan stoats are somewhat inferior to Siberian ones, and their pelts are valued lower.
The stoat is found throughout the mountains of the republic and in all altitudinal zones, but its distribution is uneven, primarily depending on two factors: the availability of food (mainly mouse-like rodents) and the availability of shelters (rocky debris, thickets, etc.). The stoat finds favorable conditions in the mid-mountain and, in places, in the high mountain regions. Its favorite habitats are wooded and shrubby areas, rocky debris. The stoat "shows a tendency towards riparian biotopes." Indeed, it is found significantly less frequently in dry gorges than in river and stream floodplains. This inclination may partly explain the low numbers of stoats in the mountains of the Osh region, which are relatively poor in water. Another possible reason could be the persecution by the marten, which is discussed in detail in the essay about the weasel.
In the Preissykul region, the stoat is found in noticeable numbers only in the humid and forested eastern part and is almost absent in the arid and treeless western part.
The population of stoats in various regions of the republic fluctuates significantly.
The highest density of stoat population, according to counts, is reached in the mid-mountain zone. The highest density is noted in the floodplains of the right tributaries of the Sary-Jaz River (44 individuals per 10 km²), which is likely associated with the abundance of rodents and the weak development of trapping in the area. However, in some places in the spruce forest belt of the Terskey Ala-Too, a similarly high population density is observed: 4 individuals per 10 km² in the Teploklyuchensky section of the Issyk-Kul State Reserve.
In terms of stoat numbers, the Preissykul region (excluding the coastal zone of the lake and the eastern part) ranks first, where the population density averages 16.7 individuals per 10 km², followed by the regions of the Internal Tien Shan (averaging 4.9 individuals per 10 km²), third are the regions of Northern Kyrgyzstan, where the mid-mountains average 4.7 individuals per 10 km², and fourth are the mid-mountain Priferghana regions, where there are on average less than 1.7 individuals per 10 km².
The stoat's diet primarily consists of mouse-like rodents (the forest mouse and various species of voles), pika in rocky debris, and occasionally others. Stomach analyses of stoats have shown that they occasionally catch small passerines. In 6 out of 12 examined stomachs, there were remains of the forest mouse, in 8—voles (some of the remains identified as narrow-skulled voles), and once each, plant matter and bird feathers were noted. It is possible that during the summer, birds play a somewhat larger role in the stoat's diet.
For example, in June in the spruce forest of the Kainy gorge of the Naryn-Tuu ridge, a large dove was found with its head bitten off (likely the result of a stoat attack), which was present here in noticeable numbers. Under the deadwood, where the animals were found, feathers of passerine birds, mainly fledglings, were discovered. Secondary food sources also include shrews and rarely lizards.
According to literary data, the stoat often kills significantly more animals than it can eat.
Sometimes it makes caches. In the mountains near Lake Son-Kul, 6 narrow-skulled voles were found under stones, with only the brain part of the skull eaten. Forest mice with their heads bitten off were found in the spruce forests of the Arashan River valley (Terskey Ala-Too).
Our observations confirm B. A. Kuznetsov's indication that: "In the mountains of Kyrgyzstan, in those places where it is little disturbed, the stoat is equally active both at night and during the day... and only where stoats are heavily disturbed by people and dogs, it becomes more cautious and begins to lead a predominantly nocturnal lifestyle."
Almost nothing is known about the reproduction of the stoat in our conditions. According to literary data, there is one breeding cycle per year. The number of young in a litter, which appears in May-June, ranges from 2 to 8, more often 4-8. At the age of 2-3 months, the young already reach the size of the mother, and by this time the females become sexually mature. Young males reach adult size and sexual maturity only in their second year of life.
Thus, the stoat is capable of rapid reproduction.
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