The Himalayan wolf (Canis lupus chanco) is a canine of debated taxonomy. It is distinguished by its genetic markers, with mitochondrial DNA indicating that it is genetically basal to the Holarctic grey wolf, genetically the same wolf as the Tibetan and Mongolian wolf, and has an association with the African wolf (Canis lupaster). No striking morphological differences are seen between the wolves from the Himalayas and those from Tibet. The Himalayan wolf lineage can be found living in Ladakh in the Himalayas, the Tibetan Plateau, and the mountains of Central Asia predominantly above in elevation because it has adapted to a low-oxygen environment, compared with other wolves that are found only at lower elevations.
Some authors have proposed the reclassification of this lineage as a separate species. In 2019, a workshop hosted by the IUCN/SSC Canid Specialist Group noted that the Himalayan wolf's distribution included the Himalayan range and the Tibetan Plateau. The group recommends that this wolf lineage be known as the "Himalayan wolf" and be classified as Canis lupus chanco until a genetic analysis of the holotypes is available. The Himalayan wolf lacks a proper morphological analysis. The wolves in India and Nepal are listed on CITES Appendix I as endangered due to international trade.
Taxonomy Canis chanco was the scientific name proposed by John Edward Gray in 1863, who described a skin of a wolf that was shot in Chinese Tartary. This specimen was classified as a wolf subspecies Canis lupus chanco by St. George Jackson Mivart in 1880. In the 19th and 20th centuries, several taxonomical nomenclature was given to various zoological specimens: Canis niger by Philip Sclater in 1874 based on pair of wolves bought alive from Tatar traders at the foot of the Lanak Pass.
Lupus filchneri by Paul Matschie in 1907 from a wolf skin from Xining in China's Qinghai province. It had been collected by Wilhelm Filchner during an expedition to China and Tibet in 1903–1905. Lupus karanorensis by Matschie in 1907 based on a skin and a skull of a wolf that was shot in an oasis near Dunhuang in China in 1894. Lupus tschiliensis by Matschie in 1907 from a skull of a wolf specimen that was shot in the coastal region of China's Zhili province. Canis lupus coreanus by Yoshio Abe in 1923 based on a wolf specimen obtained from the vicinity of Seoul in the Korean Peninsula. In 1938, Glover Morrill Allen classified these specimens as synonyms for the subspecies C. l. chanco. In 1941, Reginald Pocock corroborated this assessment after reviewing wolf skins and skulls in the collection of the Natural History Museum, London. In 2005, W. Christopher Wozencraft also listed C. l. niger, C. l. filchneri, C. l. karanorensis, and C. l. tschiliensis as synonyms for C. l. chanco.
Canis himalayensis was proposed by Aggarwal et al. in 2007 for wolf specimens from the Indian Himalayas that differed in mitochondrial DNA (mDNA) from specimens collected from other parts of India. In April 2009, it was proposed as a distinct wolf species through the nomenclature specialist on the CITES animals committee based on a single study that relied on only a limited number of museum and zoo samples that may not have been representative of the wild population. The committee recommended against this proposal, but suggested that the name be entered into the CITES species database as a synonym for Canis lupus. The committee stated that the classification was for conservation purposes only, and did not "reflect the latest state of taxonomic knowledge", and called for further fieldwork.
As per a 2018 report, this genetic lineage showed a 3.9% divergence in the mDNA cytochrome b gene when compared with the Holarctic grey wolf (Canis lupus), which may justify it being classified as a distinct species. In 2019, a workshop hosted by the IUCN/SSC Canid Specialist Group noted that the Himalayan wolf's distribution included the Himalayan range and the Tibetan Plateau. The group determined that the earliest available Latin name is Canis chanco (Gray, 1863), but the geographic location of the holotype is unclear. The group recommends that this wolf lineage be known as the "Himalayan wolf" and classified as Canis lupus chanco until a genetic analysis of the holotypes is available. In 2020, recent research on the Himalayan wolf genome indicates that it warrants species-level recognition under the Unified Species Concept, the Differential Fitness Species Concept, and the Biological Species Concept. It was identified as an evolutionary significant unit that warranted assignment onto the IUCN Red List for its protection.
Characteristics
The Himalayan wolf has a thick, woolly fur that is dull earthy-brown on the back and tail, and yellowish-white on the face, underside, and limbs. It has closely spaced black speckles on the muzzle, below the eyes, and on the upper cheeks and ears.
It is larger than the Indian and common European wolves, and reaches in length, tall at the shoulder, and weighs around on average.
The heart of the Himalayan wolf can withstand the low oxygen levels at high elevations. It has a strong selection for RYR2, a gene that initiates cardiac excitation.
Phylogeography The mitochondrial DNA of 27 wolves from the Himalayas and the Tibetan Plateau was compared in 2004. Results indicate that five related haplotypes formed a clade that is basal to all other wolves. This clade included one sample from Ladakh, nine from the Spiti Valley in Himachal Pradesh, four from Nepal, and two from Tibet. The Himalayan wolf clade diverged from other canids 800,000 years ago. Seven wolves from Kashmir did not fall into this clade. The mtDNA of 18 captive wolves in the Padmaja Naidu Himalayan Zoological Park was analysed in 2007. Results showed that they shared a common female ancestor. As this study was based on captive-bred zoo specimens that had descended from only two females, these samples were not considered to be representative. Additionally, the wolf population in the Kashmir Valley is known to have recently arrived in that area. Subsequent genetic research showed that wolf samples from Tibet are genetically basal to the Holarctic gray wolf. Its MT-ND4L gene commences with the base pairs GTG, whereas all other canids commence with ATG. Results of whole genome sequencing showed that it is the most genetically divergent wolf.
Analysis of scat samples from two wolves collected in upper Dolpo in Nepal matched the Himalayan wolf. Fecal remains of four wolves collected in the upper Mustang region of the Annapurna Conservation Area also fell within the Himalayan wolf clade but formed a separate haplotype from those previously studied.
The Himalayan wolf population in Tibet declined over the past 25,000 years and suffered a historical population bottleneck. Glaciation during the Last Glacial Maximum may have caused habitat loss, genetic isolation, and ancient inbreeding. The population in Qinghai had grown, though, showing a gene flow of 16% from Chinese indigenous dogs and 2% of the dingo's genome. It probably recolonised the Tibetan Plateau. The Himalayan wolf contrasts with the wolves living at lower elevations in Inner Mongolia, Mongolia, and Xinjiang province. Some wolves in China and Mongolia also fall within the Himalayan wolf clade, indicating a common maternal ancestor and a wide distribution. There was evidence of hybridization with the grey wolf at Sachyat-Ertash in the Issyk-Kul region of Kyrgyzstan, and of introgression from either the grey wolf or the dog into the Himalayan wolf in Nepal.
A genomic study on China's wolves included museum specimens of wolves from southern China that were collected between 1963 and 1988. The wolves in the study formed three clades: north Asian wolves that included those from northern China and eastern Russia, wolves from the Tibetan Plateau, and a unique population from southern China. One specimen located as far southeast as Jiangxi province shows evidence of being admixed between Tibetan-related wolves and other wolves in China.
DNA sequences can be mapped to reveal a phylogenetic tree that represents evolutionary relationships, with each branch point representing the divergence of two lineages from a common ancestor. On this tree, the term "basal" is used to describe a lineage that forms a branch diverging nearest to the common ancestor.
Relationship to the Indian lowland wolf In 2021, a study compared both the mitochondrial DNA and the nuclear DNA (from the cell nucleus) from the wolves of the Himalayas with those of the wolves from the lowlands of the Indian subcontinent. The genomic analyses indicate that the Himalayan wolf and the Indian lowland wolf were genetically distinct from one another. These wolves were also genetically distinct from – and genetically basal to – the other wolf populations across the northern hemisphere. These other wolves form a single mitochondrial clade, indicating that they originated from a single expansion from one region within the last 100,000 years. However, the study indicated that the Himalayan wolf had separated from this lineage 496,000 years ago, and the Indian lowland wolf 200,000 years ago.
Admixture with an unknown wolf-like canid The Tibetan Mastiff breed was able to adapt to the extreme highland conditions of the Tibetan Plateau very quickly, comparably to other mammals such as the yak, Tibetan antelope, snow leopard, and wild boar. The Tibetan Mastiff's ability to avoid hypoxia in high elevations due to its higher hemoglobin levels compared to low-altitude dogs, was due to prehistoric interbreeding with the wolves of Tibet.
In 2020, a genomic analysis indicates that the wolves of the Himalayas and the Tibetan Plateau are closely related. These wolves have an admixed history which includes gray wolves, dogs, and a ghost population of an unknown wolf-like canid. This ghost population is deeply-diverged from modern Holarctic wolves and dogs, has contributed 39% to the Himalayan wolf's nuclear genome, and contributed the EPAS1 allele which can be found in both Himalayan wolves and dogs which allows them to live in high altitudes.
Domestic dogs exhibit diverse coat colours and patterns. In many mammals, different colour patterns are the result of the regulation of the Agouti gene, which can cause hair follicles to switch from making black or brown pigments to yellow or nearly white pigments. The most common coat pattern found in modern wolves is agouti, in which the upperside of the body has banded hairs and the underside exhibits lighter shading. The colour yellow is dominant to the colour black and is found in dogs across much of the world and the dingo in Australia.