Dicerorhinus sumatrensis

The Sumatran rhinoceros, also known as the hairy rhinoceros or Asian two-horned rhinoceros (Dicerorhinus sumatrensis), is a rare member of the family Rhinocerotidae and one of five extant species of rhinoceros. It is the only extant species of the genus Dicerorhinus. It is the smallest rhinoceros, although it is still a large mammal; it stands 112–145 cm (3.67–4.76 ft) high at the shoulder, with a head-and-body length of 2.36–3.18 m (7.7–10.4 ft) and a tail of 35–70 cm (14–28 in). The weight is reported to range from 500 to 1,000 kg (1,100 to 2,200 lb), averaging 700–800 kg (1,540–1,760 lb), although there is a single record of a 2,000 kg (4,410 lb) specimen. Like both African species, it has two horns; the larger is the nasal horn, typically 15–25 cm (5.9–9.8 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran rhino's body. Members of the species once inhabited rainforests, swamps, and cloud forests in India, Bhutan, Bangladesh, Myanmar, Laos, Thailand, Malaysia, Indonesia, and China. In historical times, they lived in southwest China, particularly in Sichuan. They are now critically endangered, with only five substantial populations in the wild: four in Sumatra and one in Borneo. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number fewer than 100. Survival of the Peninsular Malaysia population is in doubt, and one of the Sumatran populations may already be extinct. In 2015, researchers announced that the Bornean rhinoceros had become extinct from the northern part of Borneo (Sabah, Malaysia); however, a tiny population was discovered in East Kalimantan in early 2016. The Sumatran rhino is a mostly solitary animal except for courtship and offspring-rearing. It is the most vocal rhino species and also communicates through marking soil with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan rhinoceros, in part because of a program that brought 40 Sumatran rhinos into captivity with the goal of preserving the species. There was little or no information about procedures that would assist in ex situ breeding. Though a number of rhinos died once at the various destinations and no offspring were produced for nearly 20 years, the rhinos were all doomed in their soon to be logged forest. In March 2016, a Sumatran rhinoceros (of the Bornean rhinoceros subspecies) was spotted in Indonesian Borneo. Malaysia's last male Sumatran rhinoceros, named Tam, died on 27 May 2019. The first documented Sumatran rhinoceros was shot 16 km (9.9 mi) outside Fort Marlborough, near the west coast of Sumatra, in 1793. Drawings of the animal, and a written description, were sent to the naturalist Joseph Banks, then president of the Royal Society of London, who published a paper on the specimen that year. In 1814, the species was given a scientific name by Johann Fischer von Waldheim, a German scientist and curator of the State Darwin Museum in Moscow, Russia. The specific epithet sumatrensis signifies 'of Sumatra', the Indonesian island where the rhinos were first discovered. Carl Linnaeus originally classified all rhinos in the genus, Rhinoceros; therefore, the species was originally identified as Rhinoceros sumatrensis or sumatranus. Joshua Brookes considered the Sumatran rhinoceros, with its two horns, a distinct genus from the one-horned Rhinoceros, and gave it the name Didermocerus in 1828. Constantin Wilhelm Lambert Gloger proposed the name Dicerorhinus in 1841. In 1868, John Edward Gray proposed the name Ceratorhinus. Normally, the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature established the proper genus name as Dicerorhinus. The three subspecies are: D. s. sumatrensis, known as the Western Sumatran rhinoceros, which has only 75 to 85 rhinos remaining, mostly in the national parks of Bukit Barisan Selatan and Kerinci Seblat, Gunung Leuser in Sumatra, but also in Way Kambas National Park in small numbers. They have recently gone extinct in Peninsular Malaysia because the last one in Malaysia, named Tam, died on 27 May 2019. The main threats against this subspecies are habitat loss and poaching. A slight genetic difference is noted between the Western Sumatran and Bornean rhinos. The rhinos in Peninsular Malaysia were once known as D. s. niger, but were later recognized to be a synonym of D. s. sumatrensis. Three males and four females currently live in captivity at the Sumatran Rhino Sanctuary at Way Kambas, the youngest male having been bred and born there in 2012. Another calf, a female, was born at the sanctuary in May 2016. The sanctuary's two males were born at the Cincinnati Zoo and Botanical Garden.