The Kodar population of the snow sheep is a unique isolate, whose range is completely closed in the Kodar ridge – the highest in the Vitimo-Olekminsky highlands. The isolation of the Kodar ram is also proved by the method of genome-wide analysis, and indicates that it is a "fragment" of the ancestral form of the snow sheep, once common in the Baikal region and Transbaikalia. Those animal co-existed there with representatives of the mammoth fauna, that disappeared now in the vast majority of the territory. The genome-wide analysis was made by the director of the Federal Research Center for Animal Husbandry named after Academy Member L.K. Enrnst academician N. A. Zinovieva and an employee of the Institute, Candidate
of Biological Sciences A.V. Dotsev. The analysis was carried out on the material obtained by Dmitry
Medvedev in 2016 from the remains of Kodar snow sheep that died in avalanches. According to geneticists, the Kodar snow sheep can be separated genetically from the Yakut snow sheep – the closest to it in geographical distribution – as an exceptionally rare representative of an isolated population of the species that lives only on the Kodar ridge.
Sometimes in the hunting and popular science literature, the Kodar ram is incorrectly called "Yablonov sheep” what focused on the old name of the Stanovoy ridge – "Yablonovy" (what means dominant) and transferring it to the Kodar ridge for some reason. it is unacceptable even from the position of elementary geography. The Yablonovy or Stanovoy Ridge stretches for 700 km from the middle course of the Olekma River to the east – to the Uchur River. The habitat of the "Yablonov sheep" (probably the Okhotsk subspecies of the snow sheep) is the far eastern parts of the Stanovoy Ridge, the sources of the Zeya River and the vicinity of the lake Toko. The Kodar ridge is located to the west of not only the Olekma River, but also the Chara River. It belongs to another mountain system – the Stanovoy Upland, which also extends west of Olekma in Northern Transbaikalia. The modern Yablonovy ridge, located in the south-west of the Trans-Baikal Territory, between the cities of Petrovsk-Zabaikalsky and Chita, has nothing to do with the modern distribution of the snow sheep and the Stanovoy ridge. it is relatively low and covered with forest.
The Kodar population has a relict character. The sheep male has the most elongated massive body on short and thick legs, the head is wide, short with a wide flat "bull" forehead, the horns are relatively thin (33.5-34 cm in circumference at the bases). Therefore, it should be considered a "thin-horn".
The body length of adult rams is 162-183 cm, the height at the withers is 94-104 cm, at the rump-104-110 cm. The circumference of the body behind the shoulder blades is 112-140 cm, the length of the ear is 8-8. 5 cm, the length of the tail is 8.8-10 cm. The body length of adult ewes is 139-144 cm, the height at the withers is 82-84 cm, at the rump is 92 cm, the body circumference behind the shoulder blades is 92-110 cm, the ear length is 7.7-8 cm, the tail length is 8-8. 5 cm. The largest confirmed length of the skull of a male Kodar snow sheep is 287.8 mm, the largest width is 188.8 mm. The maximum length of the ewe's skull is 254.1 mm, the maximum width is 162 mm.
The Kodar population of the snow sheep is also distinguished by a series of craniological features.
The main differences in the structure of the skull of the Kodar snow sheep:
1) the absence of a noticeable separation of the wedge-shaped (os sphenoidedale) and preclypoid (os praesphenoidedale) bones, which is present in other subspecies of the snow sheep and in many other mammals;
2) very narrow lacrimal bone (os lacrimale); narrow auditory chambers (bulla ossea) and narrow auditory passages, indicating a partial weakening of hearing function, which is associated with the good protective properties of the steep rocky habitats of Kodar;
3) long and strong teeth, where the lunate depressions on the 2 premolars of the upper jaw are deployed perpendicular to the length of the dentition;
4) the lacrimal bones of the Kodar sheep doesn’tt reach the nasal bones and don't separate the frontal and maxillary bones, as it happens with the Yakut, Okhotsk, Kamchatka snow sheep;
5) the cross-section of the horn rods of Kodar snow sheep is closer to oval, though Yakut, Okhotsk and Kamchatka snow sheep have rounded-triangular ones;
6) the inter-horn space between the bases of the bony horn rods in the occipital part of all the skulls of old males of the Kodar snow sheep is wide and rectangular, that passes almost unchanged through the area of the highest inter-horn point of the skull to the upper part of the forehead. The inter-horn space of the studied same-age (adult and old) skulls of Yakut, Okhotsk and Kamchatka male snow sheep is more than 2 times narrow. It has a narrow wedge-shape that extends from the occipital region with a decrease in the distance between the bases of the horn rods towards the area of the highest inter-horn point of the skull;
7) the width of the skull in the area of the supraorbital openings of Kodar snow sheep males exceeds significantly a similar indicator for the measured skulls of Yakut, Okhotsk and Kamchatka males;
8) the largest and main length of the skull of males and females of the Kodar snow sheep is proportional to the largest width of the skull less than in other subspecies.
However, they are not all the craniological differences.
The color of the Kodar sheep lacks the intense dark brown tones common for sheep of Yakutia and the Okhotsk coast. There are no spots and contrasting highlights on the sides of the Kodar snow sheep unlike the Okhotsk and Yakut subspecies. The lower parts of the limbs of individuals from Kodar are lighter than the upper ones.
The habitat of the snow sheep population on the Kodar ridge has been preserved due to the existing altitude range between the upper border of forest vegetation formed by larch and mixed forests (cedar elderberry, alder, stone birch) and the nival belt of the mountains.
The main ecological conditions of the existence of the Kodar snow sheep:
1. The Kodar Ridge is much higher than all the nearby ridges.
2. Its central, southern and south-eastern slopes, which descend into the Upper Char basin, are not snowy in winter, what creates optimal conditions for pasture turnover of various groups of the Kodar snow sheep and determines its survival.
3. The presence of a glacial "shield", where sheep normalize their thermoregulation on particularly hot days, and feed on rich and useful substances vegetation that grows on glacial water.
4. The presence of a range between the upper border of the forest and the peaks of the mountains, where the main pasture turnover of the snow sheep occurs. The steepness of the slopes in the central part of the Kodar ridge, high-elevation peaks with sharply defined Alpine relief, as well as steep Alpine slopes, rugged couloirs, denudation troughs, alternate with platform flat-topped peaks that represent a kind of "tables" with a width of several tens of meters to several kilometers. There are rocky cliffs on their sides that hang over the river valleys. These favorite habitats of the Kodar snow sheep abound in coal spots, where they eat salt.
The diet is dominated by local cereals (35%), legumes (24%), sedge (17.5%). The proportion of mosses is high (3.8%). They eat coal all year round.
The rut takes place in the second half of November – the first half of December. Lambs appear from the middle of May.
The range of the Kodar snow sheep begins to the east of 1 17° V. D., in the basin of the Sulban river. It reaches at the extreme eastern point of the high-altitude area of Kodar, bounded by the river Chara. 1 19° east longitude The extreme southern point of distribution of this rare animal is located south of 56° 40° (between 56° 40° and 56° 30°) in the mountains surrounding the river Sulban. The northernmost point of detection of sheep was near the mouth of the Senj River that corresponds to 58° s. w. Most likely, that was just a random visit of snow sheep. The real northern border of the range is located to the south and runs from the lake district. Nitschatka in the direction of Chara between 57° 50° s. w. and 57° 30° s. w. or slightly to the south.
The Kodar snow sheep is distributed on the territory of the Irkutsk Region and in the Trans-Baikal Territory (the former Chita Region), in the central part of the Kodar ridge, that is the highest in the Northern Transbaikalia and the Stanovoe Highlands (the Vitimo - Olekminsky Highlands is its component part) and has the most developed ice sheet. The presence of a more developed high-altitude zone than on the surrounding ridges, the lack of snow in a number of areas of the Kodar ridge, is decisive for the existence of the Kodar snow sheep population. It is reliably known from the mountains surrounding the sources of the Levaya Sygykta River, including its tributary the Glacial River, And on the territory of the Vitim Reserve. In the summer and autumn of 1990 D. G. Medvedev was carrying out ground and air survey research in the frames of the scientific work a and discovered snow sheep in that part of Kodar. Snow sheep and their tracks were also found significantly below the confluence of the Lednikovay River-downstream of the Left Sygykta, opposite the sources of the Sredny Sakukan River and in the area of the confluence of the right tributary of the Mastakh River. Those animals continued to be found in the above-mentioned territory in the following years of research. Thus, the fact of the sheep' habitation in the part of Kodar protected by the Vitim Reserve should be considered proven since 1990.
The subspecies is also met outside of the Irkutsk Region, in the eastern part of the ridge, that is part of the territory of the Kalarsky district of the Trans-Baikal Territory (the former Chita region). It inhabits the mountains in the upper reaches of the Middle and Upper Sakukany, Apsat, Byiki, Burgai, Syulban, Kuda Malaya and their tributaries.
The main part of the Kodar snow sheep population is concentrated in the basins of the first three rivers mentioned above. We have the information about the visits of sheep to the sources of the Right Sygykta, Hallas, Amalyk, Senh rivers, as well as to the Udokan, Kalarsky, Yuzhno-Muisky and Severo-Muisky ridges, but there is no documentary evidence of this.
According to different seasons and years of accounting the total population of the snow sheep of the Kodar ridge is from 270 to 400-500 individuals. It should be recognized as relatively stable over the years Despite the known cases of poaching. There are several dozen individuals of the Kodar snow sheep on the territory of the Irkutsk region.
The number and density of the population of the Kodar snow sheep are reduced by avalanches and rockfalls, which are very common in the steep rocky gorges of Kodar. Other reasons for the decline in numbers are the predation of the wolverine and bear, which are common there, especially during the lambing season, poaching by local reindeer herders and residents of the Charskaya basin, the development of the Apsat coal deposit, that destroys the main habitats of this rare animal.
The Kodar snow sheep is listed in the Red Books of the Chita Region and the Aginsky Autonomous Okrug (2002), in the Red Book of the Irkutsk Region (2010), in the Red Book of the Trans-Baikal Territory (2013), is a candidate for inclusion in the Red Book of the Russian Federation, and it must be listed in the IUCN Red Book.
The animal is protected on the territory of the Vitim State Natural Reserve, where the extreme western parts of the range are located. Currently, the Kodar State National Park is being organized on the Kodar Ridge, designed to preserve the main part of the sheep population in the Trans-Baikal Territory.
The urgent organization of a specialized nursery for semi-free and open-air breeding and subsequent distribution of the Kodar snow sheep in the mountain ranges of the Stanovoy Highlands is very relevant and undoubtedly necessary, in order to restore the historical range in Transbaikalia and the Baikal region. The territories of the Irkutsk Region, the Trans-Baikal Territory and the Republic of Buryatia are equally suitable for this. The borders of all these three subjects of the Russian Federation converge within the area, or are in close proximity to it.
The Kodar snow sheep is one of the rarest and narrowly territorial forms of large mammals in Russia. It inferiors in vulnerability to such figures of the Red Book of the Russian Federation as the tiger, snow leopard, Altai argali and many others. If we successfully bred, restore its number and settle in the Kodar ridge and other ridges of the Baikal Region and Transbaikalia, it’ll be able to become in the most valuable hunting animal in Eastern Siberia the future, as well as the subject of pilgrimage for tourists, including fans of photo and video hunting.
