Tibetan wild ass, Equus kiang, in the literature: a comprehensive review

Abstract

The Tibetan wild ass (Equus kiang) is primarily located on the Tibetan Plateau and in the Ladakh region of India. This species is recognised as the only odd-toed ungulate within the order Perissodactyla, family Equidae, and genus Equus. According to the International Union for Conservation of Nature (IUCN), E. kiang is classified as a species of Least Concern; however, the subspecies Equus k. kiang, which inhabits the Changthang Wildlife Sanctuary in Ladakh, is categorised as Data Deficient by the IUCN. To rigorously assess the validity of the Data Deficient classification of E. k. kiang, a comprehensive literature review was undertaken utilising search terms including “E. kiang”, “Asiatic Wild Ass”, “Tibetan Wild Ass”, and “kiang” on platforms such as PubMed (NCBI) and Google Scholar. The results consistently demonstrated that the majority of the literature concentrates on the ecological and behavioural attributes of the kiang, while there is limited focus on genetic factors. Most genetic studies have prioritised the estimation of genetic diversity and the execution of phylogenetic analyses; however, none have sufficiently investigated the population structure. Notably, there is a significant paucity of research on the whole-genome sequencing of E. kiang, and to date, no nucleotide sequences from India have been submitted to GenBank. Consequently, it can be inferred that while E. kiang is designated as a species of Least Concern, its subspecies, E. k. kiang, remains Data Deficient. It is strongly recommended that future research employ molecular markers such as mitochondrial DNA D-loop markers, microsatellite (MSAT) markers, and single-nucleotide polymorphism (SNP) markers to evaluate the population structure of this resilient equid.