The evolutionary relationships between extinct and extant lineages provide important insight into species’ response to environmental change. The grey wolf is among the few Holarctic large carnivores that survived the Late Pleistocene megafaunal extinctions, responding to that period’s profound environmental changes with loss of distinct lineages and phylogeographic shifts, and undergoing domestication. We reconstructed global genome-wide phylogeographic patterns in modern wolves, including previously underrepresented Siberian wolves, and assessed their evolutionary relationships with a previously genotyped wolf from Taimyr, Siberia, dated at 35 Kya. The inferred phylogeographic structure was affected by admixture with dogs, coyotes and golden jackals, stressing the importance of accounting for this process in phylogeographic studies. The Taimyr lineage was distinct from modern Siberian wolves and constituted a sister lineage of modern Eurasian wolves and domestic dogs, with an ambiguous position relative to North American wolves. We detected gene flow from the Taimyr lineage to Arctic dog breeds, but population clustering methods indicated closer similarity of the Taimyr wolf to modern wolves than dogs, implying complex post-divergence relationships among these lineages. Our study shows that introgression from ecologically diverse con-specific and con-generic populations was common in wolves’ evolutionary history, and could have facilitated their adaptation to environmental change.

The intraspecific taxonomy of snow sheep (Ovis nivicola) is one of the most controversial issues in Caprinae systematics. Although eight subspecies have been described using morphological traits, the validity of several taxa, particularly those in the eastern part of their geographical range, remains disputed. We investigated the phylogenetic relationships and genetic diversity of snow sheep in the Chukotka Autonomous Okrug using genome-wide single-nucleotide polymorphism (SNP) data (935 loci after filtering) and complete mitochondrial genomes from 57 individuals collected across the Russian Far East (Chukotka Autonomous Okrug, Kamchatka Krai, Magadan Oblast, and Republic of Sakha (Yakutia)). Post SNP-genotyping nuclear genomic studies using principal component analysis (PCA), ADMIXTURE, pairwise F_ST and Neighbor-Net revealed two clearly differentiated groups within Chukotka. One included individuals from the Koryak Mountains that are genetically indistinguishable from the Koryak subspecies (O. n. koriakorum) of northern Kamchatka. The other one encompassed individuals from the Anadyr Plateau and the Chukotka Mountains cluster with the Okhotsk subspecies (O. n. alleni) of the Kolyma Mountains. Bayesian phylogeny of complete mitochondrial genomes fully corroborated the nuclear results: Koryak Mountains samples formed a monophyletic clade, while Anadyr–Chukotka samples grouped with Kolyma Mountains individuals. Genetic diversity indices (_UH_E, A_R, F_IS) in both Chukotka groups were comparable to other studied populations and showed no signs of inbreeding depression. Our results provide important insights and can be used to develop science-based strategies for preserving the population-genetic diversity of snow sheep.

The article presents data on the morphology, range, and number of the American mink in Yakutia, gives materials on its morpho- and craniometry. Data on the dynamics of the range and number of the American mink in Yakutia from the moment of its introduction in the early 1960s to the present time are shown. The range of the mink has expanded in the northeast direction from Southern Yakutia to Central Yakutia for half a century, and new mink settlement sites on the eastern side of Yakutia from Magadan Region have been noted. After naturalization of the American mink for 25 years, there was a gradual increase in its number from 686 individuals to 4000–5000 individuals. Over the next 35 years, the number of the species stabilized and has remained at this level with some fluctuations over the years, excluding 2005–2006, when there was a sharp increase in the number of mink.

The northern pika (Ochotona hyperborea Pallas) is a small herbivorous animal from the Ochtonidae family, widely distributed in the mountains of Northeast Asia. Despite its small size, the northern pika plays a noticeable role in the transformation of organic substances of biocenoses. An essential feature of these mammals is the procurement of plant food for the winter period. The food ration of the animals is very diverse and depends on the structure of the surrounding vegetation. It includes aerial parts of shrubs, sub‑shrubs, herbaceous plants, ferns, Equisetum species, rarely trees, bushy lichens, fungi and very rarely mosses. According to our analysis of the literature data, more than 220 species of vascular plants are included in the diet of the northern pika in Northeast Asia. During a survey of the northern spurs of the Chuvansky Range in the basin of the Ozernoe Gorlo river (Anadyr river basin), 14 species of vascular plants, 8 species of bushy lichens and 1 species of moss were identified in winter stocks of the northern pika on 2 terrain areas differing in landscape and vegetation structure. Salix pulchra, S. berberifolia subsp. tschuktschorum, Chamaenerion latifolium, Vaccinium uliginosum subsp. microphyllum, Empetrum nigrum, Ledum palustre subsp. Decumbens are of great importance as the preferred food of northern pika in this territory. In addition, the Dryopteris fragrans fern and more rarely Betula nana, are harvested quite sustainably in one of the sections of a stone scree (stone run) surrounded by a Pinus pumila community. The role of bushy lichens and mosses in the nutrition of the northern pika needs to be clarified.

Relevance. For the first time, comprehensive landscape-geochemical studies were conducted in the Buotama, Amga and Vostochnaya Khandyga river basins of Yakutia. The studies included the chemical composition of natural waters, soils, forage grasses, and rocks eaten by animals on kudurs, landscape complexes visited by animals for long periods of time for geophagy and specifically transformed by them. Aim. To determine the cause of geophagy occurring in these areas among wild and domestic animals. Methods. Atomic emission spectrometry, mass spectrometry, ion chromatography, analytical electron scanning microscope with energy-dispersive spectrometer. Results. It was revealed that geophagy in Yakutia is widespread both in mountainous and flat areas in landscapes with low contents of mobile forms of rare earth elements that can accumulate in feed and drinking water. It is assumed that the deficiency of rare earth elements in the diet of animals causes a disruption in their body metabolism of this group of elements in the nervous and endocrine systems, which is accompanied by specific hormonal stress. The state of stress forces animals to look for ways to minimize the problem that has arisen. They solve it by consuming mineral or organomineral sorbents (mainly clay rocks and peat soils) relatively enriched with rare earth elements in places where they are slightly saline, mainly with carbonate salts of calcium, magnesium and sodium. Such salts create an alkaline environment favorable for the formation of clay mineral sorbents that are capable of accumulating ions of rare earth elements. In addition, sodium salts, by affecting the central nervous system, help animals alleviate the state of stress.

The snow sheep ( Ovis nivicola ) is a wild mountain artiodactyl inhabiting the highlands of northeastern Siberia and the Russian Far East. Despite its ecological and conservation importance, the intraspecific taxonomy of this species has long remained controversial due to its broad distribution, morphological variability and limited available material. In this study, we performed a comprehensive genome‐wide single nucleotide polymorphism (SNP) analysis, encompassing all major described populations to clarify the evolutionary relationships and taxonomic structure of snow sheep. A total of 337 individuals from 15 populations were genotyped using Illumina OvineSNP50 and OvineHD 600 K BeadChips, with 1032 autosomal SNPs retained after quality filtering. Population structure analyses revealed eight major genetic clusters largely corresponding to geographic regions: Kamchatkan, Koryak, Okhotsk/Chukotka, Yakutian (Moma Range), Yakutian (Verkhoyansk Range), Yablonov, Kharaulakh and Putorana. Pairwise F _ST values confirmed substantial differentiation among most populations. Using f ₃ ‐statistics, two significant admixture events were identified, one involving the Orulgan and another the northern Kamchatka populations. Based on the integrated genomic and historical evidence, our results support the taxonomic recognition of the Kamchatkan ( O. n. nivicola ), Putorana ( O. n. borealis ), Okhotsk ( O. n. alleni ), Koryak ( O. n. koriakorum ), Yakutian ( O. n. lydekkeri ), and Stanovoy/Yablonov ( O. n. potanini ) subspecies, and propose recognition of the Kharaulakh snow sheep as a new subspecies, O. n. ernsti . The Kodar population, characterized by extremely low heterozygosity, requires further sampling to resolve its taxonomic position. These findings provide the first genome‐wide framework for understanding the evolutionary history of snow sheep and establish a genetic basis for future conservation management.