Dhole

The dhole is a canid native to South, East and Southeast Asia. It is anatomically distinguished from members of the genus Canis in several aspects: its skull is convex rather than concave in profile, it lacks a third lower molar, and the upper molars possess only a single cusp as opposed to between two and four. During the Pleistocene, the dhole ranged throughout Asia, with its range also extending into Europe but became restricted to its historical range 12,000–18,000 years ago. It is now extinct in Central Asia, parts of Southeast Asia, and possibly the Korean peninsula and Russia.
The dhole is a highly social animal, living in large clans without rigid dominance hierarchies and containing multiple breeding females. Such clans usually consist of about 12 individuals, but groups of over 40 are known. It is a diurnal pack hunter which preferentially targets large and medium-sized ungulates. In tropical forests, the dhole competes with the tiger and the leopard, targeting somewhat different prey species, but still with substantial dietary overlap.
It is listed as Endangered on the IUCN Red List, as populations are decreasing and estimated to comprise fewer than 2,500 mature individuals. Factors contributing to this decline include habitat loss, loss of prey, competition with other species, persecution due to livestock predation, and disease transfer from domestic dogs.

Etymology and naming

The etymology of "dhole" is unclear. The possible earliest written use of the word in English occurred in 1808 by soldier Thomas Williamson, who encountered the animal in Ramghur district, India. He stated that dhole was a common local name for the species. In 1827, Charles Hamilton Smith claimed that it was derived from a language spoken in 'various parts of the East'.
Two years later, Smith connected this word with 'mad, crazy', and erroneously compared the Turkish word with and , which are in fact from the Proto-Germanic *dwalaz 'foolish, stupid'. Richard Lydekker wrote nearly 80 years later that the word was not used by the natives living within the species' range. The Merriam-Webster Dictionary theorises that it may have come from the.
Other English names for the species include Asian wild dog, Asiatic wild dog, Indian wild dog, whistling dog, red dog, and red wolf.

Taxonomy and evolution

Canis alpinus was the binomial name proposed by Peter Simon Pallas in 1811, who described its range as encompassing the upper levels of Udskoi Ostrog in Amurland, towards the eastern side and in the region of the upper Lena River, around the Yenisei River and occasionally crossing into China. This northern Russian range reported by Pallas during the 18th and 19th centuries is "considerably north" of where this species occurs today.
Canis primaevus was a name proposed by Brian Houghton Hodgson in 1833 who thought that the dhole was a primitive Canis form and the progenitor of the domestic dog. Hodgson later took note of the dhole's physical distinctiveness from the genus Canis and proposed the genus Cuon.
The first study on the origins of the species was conducted by paleontologist Erich Thenius, who concluded in 1955 that the dhole was a post-Pleistocene descendant of a golden jackal-like ancestor. The paleontologist Bjorn Kurten wrote in his 1968 book Pleistocene Mammals of Europe that the primitive dhole Canis majori Del Campana 1913 —the remains of which have been found in Villafranchian era Valdarno, Italy and in China—was almost indistinguishable from the genus Canis. In comparison, the modern species has greatly reduced molars and the cusps have developed into sharply trenchant points. During the Early Middle Pleistocene there arose both Canis majori stehlini that was the size of a large wolf, and the early dhole Canis alpinus Pallas 1811 which first appeared at Hundsheim and Mosbach in Germany. In the Late Pleistocene era the European dhole was modern-looking and the transformation of the lower molar into a single cusped, slicing tooth had been completed; however, its size was comparable with that of a wolf. This subspecies became extinct in Europe at the end of the late Würm period, but the species as a whole still inhabits a large area of Asia. The European dhole may have survived up until the early Holocene in the Iberian Peninsula, and what is believed to be dhole remains have been found at Riparo Fredian in northern Italy dated 10,800 years old.
The vast Pleistocene range of this species also included numerous islands in Asia that this species no longer inhabits, such as Sri Lanka, Borneo and possibly Palawan in the Philippines. Middle Pleistocene dhole fossils have also been found in the Matsukae Cave in northern Kyushu Island in western Japan and in the Lower Kuzuu fauna in Tochigi Prefecture in Honshu Island, east Japan. Dhole fossils from the Late Pleistocene dated to about 10,700 years before present are known from the Luobi Cave or Luobi-Dong cave in Hainan Island in south China where they no longer exist. Additionally, fossils of canidae possibly belonging to dhole have been excavated from Dajia River in Taichung County, Taiwan.
A single record of the dhole is known from North America. This consists of a jaw fragment and teeth of Late Pleistocene age found in San Josecito Cave in northeast Mexico, dating to around 27,000–11,000 years ago. Other researchers have either considered this record as "insufficient" or suggested that further corroboration is required for the definitive taxonomic attribution of these specimens.
Dholes are also known from the Middle and Late Pleistocene fossil record of Europe. In 2021, the analyses of the mitochondrial genomes extracted from the fossil remains of two extinct European dhole specimens from the Jáchymka cave, Czech Republic dated 35,000–45,000 years old indicate that these were genetically basal to modern dholes and possessed much greater genetic diversity.
The dhole's distinctive morphology has been a source of much confusion in determining the species' systematic position among the Canidae. George Simpson placed the dhole in the subfamily Simocyoninae alongside the African wild dog and the bush dog, on account of all three species' similar dentition. Subsequent authors, including Juliet Clutton-Brock, noted greater morphological similarities to canids of the genera Canis, Dusicyon and Alopex than to either Speothos or Lycaon, with any resemblance to the latter two being due to convergent evolution.
Some authors consider the extinct Canis subgenus Xenocyon as ancestral to both the genus Lycaon and the genus Cuon. Subsequent studies on the canid genome revealed that the dhole and African wild dog are closely related to members of the genus Canis. This closeness to Canis may have been confirmed in a menagerie in Madras, where according to zoologist Reginald Innes Pocock there is a record of a dhole that interbred with a golden jackal. DNA sequencing of the Sardinian dhole an extinct small canine species formerly native to the island of Sardinia in the Mediterranean, and which has often been suggested to have descended from Xenocyon, has found that it is most closely related to the living dhole among canines.

Admixture with the African wild dog

In 2018, whole genome sequencing was used to compare all members of the genus Canis, along with the dhole and the African wild dog. There was strong evidence of ancient genetic admixture between the dhole and the African wild dog. Today, their ranges are remote from each other; however, during the Pleistocene era the dhole could be found as far west as Europe. The study proposes that the dhole's distribution may have once included the Middle East, from where it may have admixed with the African wild dog in North Africa. However, there is no evidence of the dhole having existed in the Middle East nor North Africa, though the Lycaon was present in Europe during the Early Pleistocene, with its last record in the region dating to 830,000 years ago. Genetic evidence from the Sardinan dhole suggests that both Sardinian and modern dholes share ancestry from the Lycaon lineage, but this ancestry is significantly higher in modern dholes than in the Sardinian dhole.

Subspecies

Historically, up to ten subspecies of dholes have been recognised., seven subspecies are recognised.
However, studies on the dhole's mtDNA and microsatellite genotype showed no clear subspecific distinctions. Nevertheless, two major phylogeographic groupings were discovered in dholes of the Asian mainland, which likely diverged during a glaciation event. One population extends from South, Central and North India into Myanmar, and the other extends from India north of the Ganges into northeastern India, Myanmar, Thailand and the Malaysian Peninsula. The origin of dholes in Sumatra and Java is, as of 2005, unclear, as they show greater relatedness to dholes in India, Myanmar and China rather than with those in nearby Malaysia. However, the Canid Specialist Group of the International Union for the Conservation of Nature states that further research is needed because all of the samples were from the southern part of this species' range and the Tien Shan subspecies has distinct morphology.
In the absence of further data, the researchers involved in the study speculated that Javan and Sumatran dholes could have been introduced to the islands by humans. Fossils of dhole from the early Middle Pleistocene have been found in Java.

Subspecies	Image	Trinomial authority	Description	Distribution	Synonyms
C. a. adjustus Burmese dhole, Indian dhole		Pocock, 1941	Reddish coat, short hair on the paws and black whiskers	Northeastern India and south of the Ganges River, northern Myanmar	antiquus, dukhunensis
C. a. alpinus Ussuri dhole		Pallas, 1811	Thick tawny red coat, greyish neck and ochre muzzle	East of the eastern Sayan Mountains, eastern Russia, northeastern Asia	–
C. a. fumosus		Pocock, 1936	Luxuriant yellowish-red coat, dark back and grey neck	Western Sichuan, China and Mongolia. Southern Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia and Java, Indonesia	infuscus, javanicus
†C. a. hesperius Tien Shan dhole		Afanasjev and Zolotarev, 1935	Long yellow tinted coat, white underside and pale whiskers Smaller than C. a. alpinus, with wider skull and lighter-coloured winter fur.	Altai, Tian Shan and Pamir mountain ranges. Currently considered to be extinct since 1946.	jason
C. a. laniger		Pocock, 1936	Full, yellowish-grey coat, tail not black but same colour as body	Southern Tibet, Himalayan Nepal, Sikkim, Bhutan and Kashmir	grayiformis, primaevus
C. a. lepturus		Heude, 1892	Uniform red coat with thick underfur	South of the Yangtze River, China	clamitans, rutilans, sumatrensis
Sumatran dhole and Javan dhole C. a. sumatrensis		Hardwicke, 1821	Red coat and dark whiskers	Sumatra, Indonesia Its range is highly fragmented with multiple protected areas in Sumatra and Java.