The Chiru is the only large mammal species endemic to the Tibetan Plateau. Its horns have no age rings, and there is no evidence that they continue to grow after males reach adulthood at about four years of age.

Names

Chinese: Zang-lin [5], 藏羚羊, zàng; cáng líng yáng [1]

English common name: Chiru, Tibetan Antelope [1, 3]

French: Chiru [3, 5], Tchirou [2], Antilope du Tibet (1, 5)

German: Chiru [1], Tschiru [3, 5],  Orongo, Tibetantilope [5]

Ladakhi: stos or tos [1]

Mongolian: Orongo or orong [1]

Nepali: Chiru [5]

Spanish: Antilope tibetano [3, 5], Antílope del Tibet [1]

Tibetan: Nawa, tsus, chuhu, chiru, tsö [5] – (also see below „Year-specific names“)

The name Pantholops derives from the Greek pans, meaning „all“, and antholops, meaning „antelope“. In consequence, the animal is often called Tibetan antelope in English. This is an obvious misnomer, based upon the resemblance of the male Chiru to African antelopes. [1]

The frequently used word „chiru“ is held to be a local Tibetan name. However, there is no written Tibetan word, in any of the textual sources, which could be pronounced in this way and specifically denote this animal. The Mongolian „Orongo“ is misleading, since there are no Tibetan Antelope in Mongolia, where the word „Orongo“ refers to smaller species of gazelles whose horns are curved backwards rather than erect (Huber 2005).

Year-specific names reflect the importance of Chiru to native Tibetans – names are based in part on dentition and horn growth (Huber 2005) [1]. For example:

  • one year old: gtsod-ris, ris-thog or ri’u for (both sexes)
  • two years old: tshe-ris-ma and ra-bzbi for females, sgam-gtsod and rna-bzhi for males
  • four years old: so-drug (both sexes) – meaning „six teeth“
  • eight years old: chib-gsum (both sexes) – meaning three units of measurement (likely related to horn growth in males)

Taxonomy

Antilope hodgsonii: Abel, 1826:233-234. Type locality „Tingri Maidan, a fine plain or valley, through which the Arrun flows … beyond the snows made by Kooti pass (S. Tibet).“

Antilope (Oryx) kemas?: Hamilton-Smith, 1827:196, 199. Type locality „Chandang, north-west of Digurgu, in the Himalaya mountains“; described as the „Unicorn Chiru of Bhote, in all likelihood, the Unicorn of the ancient Persians“.

Antilope chiru: Lesson 1827: 371. Type locality „les habitans du Ne’paul“ (S. Nepal)

Antilope (Pantholops) hodgsonii: Hodgson, 1834:81. Name combination

Pantholops hodgsonii: Hodgson, 1842:282. First use of current name combination

Kemas hodgsonii: Gray, 1843:157. Name combination and incorrect subsequent spelling of Antilope hodgsonii, Abel 1826 [1]

Molecular and morphological studies align the Chiru most closely with Caprinae. In the past, it has been classified alone in a tribe Pantholopini or with Saigas (Saiga spp.) in a separate tribe Saigini because of unique behavioural and morphological characteristics. Monotypic. [3] A. W. Gentry (1992) was the first to definitively seperate this genus from Saiga and include it in the Caprini.

Despite the split the Chiru shares various features with the Saiga, in particular, the long, mediolaterally compressed, keeled horn cores; the frontal sinuses; the absence of lateral prongs on the nasal tips; the zygomatic arch that expands below the orbit; and the weak distal flanges of the metatarsals. Gentry’s demonstration that the Chiru is a caprin has since been corroborated by Gatesy et al. (1997), followed by Lei, Jiang, et al. (2003), Ropiquet and Hassanin (2005), and other molecular studies that included this genus. The Chiru is, nonetheless, in an isolated position. Thus it is sister to the rest of the Caprini. [4]

Similar species

Saiga is of comparable mass, but horns of Chiru are straighter and much longer. The Chiru can be distinguished from the sympatric Tibetan Gazelle (Procapra picticaudata) and other Asiatic gazelles, such as Goitered Gazelle (Gazella subgutturosa) and Mongolian Gazelle (Procapra gutturosa), by the long upright lyre-shaped horns of the males, the enlarged snout, and fine undercoat of the pelage. [5]

Distribution

The Chiru is endemic to the Tibetan Plateau in the Chinese provinces of Xinjiang, Qinghai, and Xizang. [3] In fact it is the only large mammal species that is completely endemic to the Tibetan Plateau. The distribution range extends 1.600 kilometres from the Ladakh border, between India and China into Qinghai province of China. [1] It also occurs (seasonally [5]) in very small numbers in Ladakh, Northwest India, mainly during summer. [3]

They formerly ranged across the whole Tibetan Plateau and are now regionally extinct, for example in Nepal. They are also absent today from all or most of the eastern plateau. [2] And the current range is now divided into two areas:

a northern one of about 490.000 km² and a central one of about 115.000 km². The distribution between the two areas was continuous until recent decades and there may still be rare contact near the western end. Although the distribution area seems large, the distribution is patchy or seasonal, leaving much terrain virtually unoccupied. [1] The main stronghold of the species is in the remote Chang Tang area of Northwest Tibet. [2]

General discription

length / head-body: 100-140 cm; males are larger; in general somewhat chunky [3]

shoulder height: 79-94 cm [3]; most adult males 80-90 cm; females considerably smaller: 70-75 cm [1]

weight: 24-42 kg [3]; males 35-45 kg, females 25-30 kg [1]

head: blunt; there are lateral nasal chambers on each side of the nostril which can give the muzzle a conspicuously swollen or puffy appearance, [1] especially when they are inflated to the size of small eggs [5] or walnuts, more so in males. [3]. The purpose of these air sacs and the short and broad nasals with large nasal apertures has been a matter of speculation. It was assumed that they assist breathing in some manner, but Schaller (1998) hypothesizes that they may play a role in vocalizations during rut. [1]

legs: slender [3]

tail: 13-14 cm [3]

horn length: only males; usually measuring 54-60 cm [3]; 50-60 cm [1]

glands: lacks preorbital and pedal glands, but does have large inguinal (belly) glands, developed to fist size in males. [1, 3]

life expectancy: No individuals have been maintained long enough in captivity to document longevity. As with other ungulates of comparable size, maximum life span in the wild is likely about ten years [3]; likely 10 plus years [1]

karyotype: 2n = 60 [1]

Chiru horns measure up to 60 centimetres. Photo: Coke Smith

Coloration / pelage

Pelage is dense and woolly, and the undercoat is very fine. [3]

overall body colour of males in summer: pale to reddish-fawn [1]

overall body colour in winter: grayer [1]

nuptial pelage (during mating season) – in males older than 3 to 5 years: striking whitish contrasting with an almost black face and black stripes on the front of the legs. [3]

underside: whitish [3], beige or off white [1]

rump patch: not distinct in both sexes [3]

legs: greyish; males have black stripes running down the front of the legs. [3]

hooves: long and narrow, dewclaws small, but broad [5]

dorsal stripe: not existing

head: Face (of males?) – including forehead, bridge of the nose, and upper cheeks – is also dark brown to black. The coloration of the muzzle swellings in males varies from greyish-brown in Xizang and Qinghai, to white in Xinjiang. [1, 3]

ears: short, somewhat pointed, and white at the back [1]

dental formula: I 0/3, C 0/1, P 2/2, M 3/3 (x 2) = 28 – reduced because of the absence of an upper and lower premolar. The missing pair of premolars is similar to that of Saigas, which lack the anterior lower premolars; loss of such dentition is probably related to diet. Canines are incisoriform, and the upper molars have pronounced external folds; the lobes are concave between and almost without medial ribs. The deciduous teeth are replaced first, with permanent incisors and third molars beginning to appear at about twelve months of age, and full permanent dentition at 28 to 30 months. Aver 2,5 years, the age of a Chiru can be determined only by general wear in the center of molar cusps, which begins on the first molar and progresses to the third molar as an individual ages. Aging by counts of cementum annuli has not been satisfactory. [3]

ears: short; somewhat pointed and white on the back [3]

tail: short and not tufted, coloured like the rump and back [3]

The rump patch in Chiru is not conspicous. Photo: Coke Smith

Horns

Only in males: slender, long, lyre-shaped black with circular rings toward their base. [3] The tips point forward. [1] The horns are remarkably uniform in length, usually measuring 54 to 60 cm. Horns longer than 70 cm are extreme. [3] The longest measured horn as recorded in Rowland Ward (2010) is about 70,5 cm. [1] The circumference at the base of the horn averages 12 cm. (3) The mean girth of 29 specimens listed in Rowland Ward is 14 cm. [1] The greatest variation is in the tip to tip span, which ranges from 19 to 46 cm [3]; in Rowland Ward the extremes are between 23,5 cm and 48,9 cm. [1] Horns have no age rings, and there is no evidence that they continue to grow after males reach adulthood at about four years of age. In profile, the upright and often symmetrical horns on adult male Chirus led to early descriptions like „Unicorn of the ancient Persians“. [3]

Horns in Chiru are lyra-shaped. Photo: Coke Smith

Sexual dimorphism

Males are larger. Only males wear horns. The lateral nasal chambers are more swollen (walnut-sized) in males. [3]

Habitat

Chirus inhabit alpine and desert steppe with flat to rolling terrain in about 800.000 km² of the Tibetan Plateau at elevations of 3250-5500 m. Such habitats are typified by sparse vegetation cover (10 to 15 percent) and low primary productivity (80 to 160 kg/ha dry matter). Chirus occur infrequently in mountain terrain. [3]

Female Chiru in typical habitat. (Two Tibetan Gazelles in the background). Photo: Coke Smith

Predators

Wolf, [5, 6], Red Fox (Vulpes vulpes), Lynx (Lynx lynx), Snow Leopard (Unica unica), domestic dogs [6]

Food and feeding

The Chiru is a mixed feeder, seasonally eating grasses, sedges, forbs, and select parts of dwarf woody plants, although dietary diversity is constrained substantially by limited forage availability and diversity on the Tibetan Plateau and by local variation. Overall, grasses and sedges represent 33 to 66 percent of the diet, being most abundant in winter diets when Chirus dig through snow to obtain forage. Seasonally, the grass Stipa is important in winter; the sedge Kobresia is eaten most often in alpine meadows and steppe habitats in summer, and the dwarf shrub Ceratoides compacta is eaten most often in desert steppe and less so in alpine steppe. [3]

In Chang Tang National Nature Reserve, Xizang, annual percent use of various plants is graminoids (gras): Stipa, 3,7 to 47,3 percent; Kobresia, 1,1 to 33,1 percent, Carex moorcroftii, 0,5 to 22,8 percent; herbaceous plants: Potentilla bifurca, 0,3 to 31,1 percent, Leontopodium, 0,2 to 11,9 percent; and dwarf shrubs: Ceratoides compacta, 0,2 to 63,5 percent, Ajania fruticulosa, 21,2 percent. [3]

Summer diets of spatially segregated male and female Chirus in Yeniugou, Qinghai, are somewhat different. There, males select Kobresia and forbs, and females select forbs, notably Potentilla, and avoid grasses and sedges. On calving grounds in desert steppe in the Western Kunlun Mountains of Xinjiang, ruminal contents of adult females had 57 percent Ceratoides compacta and 43 percent grasses and sedges. [3]

Breeding

sexual maturity: not clearly understood but, as in other ungulates of comparable size, it probably occurs at 1,5 to 2,5 years of age [3]

breeding season: November to December [3]

breeding season activity: Male hierarchy is not based on age, because males attain maximum size and horn length at about four years of age. Mature males are not territorial, but they form harems of up to about twelve females. [3]

Observations of the number of females per harem in Chang Tang Nature Reserve are 1 to 4 females in 70 percent of them, 5 to 8 females in 25 percent, and more than 9 females in 5 percent. [3]

Male Chirus tend to space themselves individually throughout rutting areas and avoid serious horn-to-horn combat with various displays and interactions [3]:

– head-up (28 percent of 54 interactions),

– neck-low (28 percent),

– chases (22 percent),

– exaggerated head-down (18 percent),

– sparrinng (only 4 percent)

Most aggressive interactions involve a male trotting or lunging with head down and horns aimed at a rival; such behaviour often terminates the interaction, but as rut intensifies, chases of up to 1 kilometre are not uncommon. [3] Fights between males break out frequently, and are extremely fierce. One or both of the contestants may perish as the result of wounds inflicted by the sharp horns. [5]

Vocalistations of rutting males may involve the enlarged nasal sinuses that serve as resonators, and include growls, croaks, and rather deep-toned roars. [3]

Courtship and mating are abrupt and brief, with only cursory displays and contacts. Early in rut, a male spends considerable time chasing females to maintain his harem; the females act disinterested. As rut progresses, females tolerate closer proximity of males and may circle back toward them when chased. When a female is receptive, the male approaches her with his head up in a distinctive walking gait, with forelegs stiff and raised high. While in close proximity to females, males do not display many of the courting behaviours common among ungulates; front-leg kicks that skim a female’s thigh are common, but the crouching, low-stretch behaviour upon approach and vulva sniffing, nuzzling, and licking have not been observed. Occasionally, males display a lip curl after inspecting an area where a female has urinated or defecated. A male copulates by rearing upright, balancing on his hind legs, with minimal contact with his mate. [3]

gestation: 6-6,5 month [1, 3]

lambing season: late June to early July [3]

young per birth: single [3]

Neonates are precocial. They can arise and nurse 12 to 15 minutes postpartum and follow their mother after one hour. Mean body mass and mean shoulder heights of young Chirus are: 4-month-olds, 15,5 kg and 63,4 cm; 16-month-old females, 20,9 kg and 67 cm; and 16-month-old males, 25,5 kg and 76,8 cm. Ratios of young Chirus to adult females suggest that typically up to two thirds of individuals die before two years of age. Years of near-complete reproductive failure occur from extreme weather before, during and after parturition. [3]

Activity patterns

There is little information available on specific daily activity patterns of Chirus, but they do forage while migrating.

Oestrid flies (gadflies) directly affect Chiru activities and behaviour in summer: One fly species burrows under the skin and consumes flesh on the rump and lower back before emerging. Other species infect the nasal sinuses and the throat. Harassment by these flies causes Chirus to stand in groups of 50 or more in knee-deep water or on mudflats, ice patches, or high ridges, and perhaps explains why they dig their characteristic summer bowl-shaped hollows. [3]

Chiru dig hollows: Chiru paw out roughly circular hollows in sandy and silty soil, about 110 to 120 cm in diameter and 15 to 30 cm deep. These hollows are distinctive, and the seasonal use of these hollows, their dispersion, and the lack of feces appear related and suggest that the hollows function primarily to conceal Chiru from ostrid flies, which probably find hosts by sight and smell (Schaller 1998). [1] The behaviour is also thought to involve predator avoidance. [3]

Movements, Home range and Social organisation

Chirus are either migratory or sedentary (perhaps facultative), and both types generally display sexual segregation from January through October (outside the breeding period). Deep snows can cause Chirus to modify traditional migratory movements in search of forage and as a means of avoidance. They are not suited for efficient travel through snow. [3] Local densities are around 0.03-9.21 individuals/km², with an average of 1.77 animals per km². [6]

Chiru movement: ill timed or survival strategy? Oddly, migratory individuals of both sexes often leave winter ranges just when forage quality is beginning to increase in spring and move north into areas where vegetation is still dormant and apparently of lower quality. Satellite imagery between 2000 and 2004 in Xinjiang showed that primary production was more than twice as high on the winter range of the Chiru as it was on calving grounds when the females arrived to give birth. Such northward migration to calve seems ill timed relative to phenology, weather, stage of pregnancy, insect harassment, and ease of movement. It may be that Chirus still follow low migratory patterns that were established when glacial and vegetative conditions were different. Females also may be moving to calving grounds with low numbers of predators and other sympatric ungulates. [3]

Males often seem not to follow a particular movement pattern: Migratory females move greater distances than males, particularly in late spring-early summer when they can travel 300 to 400 kilometres north to traditional calving grounds. Movement patterns of male Chirus are more diverse and leisurely, seemingly taking advantage of favourable forage availability, particularly in spring. Some males move to higher elevations in spring, apparently following new growth of vegetation. Some males move little between winter, summer, and rutting areas; others move short distances between winter and summer ranges; and still others move northward after winter and disperse widely, returning to rut in autumn. [3]

Group of male Chiru. Photo: Coke Smith

Chirus are gregarious, and group sizes vary considerably depending on sex, time of year, migratory patterns, weather, and insect harassment. Probably the only long-lasting association is between a female and her young-of-the-year into its second year. [3]

Sex ratios: Monthly adult sex ratios suggest differential mortality of males, not uncommon to ungulates. Winter sex rations of migratory Chirus in Chang Tang Nature Reserve, where females and males occupy the same area, are 35-75 males to 100 females. [3]

Status and conservation

IUCN Red List Category (2016): „near threatened“ [2]

Numbers and distribution of Chiru have both decreased sharply as a result of commercial hunting for the underfur in the 1980s-1990s. [2] From a high of perhaps a million or more, the extant population of Chirus was estimated at only 65.000 to 72.500 in the mid-1990s. [3]

Rigorous protection has allowed the population to increase recently, possibly to double the size it was in the mid-1990s. The species was recently assessed as „near Threatened“ on the Chinese National Red List of Vertebrates. It is also assessed as „near Threatened“ by the IUCN in 2016, because the current status can only be maintained with continued high levels of protection in its natural range and strict controls on trade and manufacture of the shawls made from its underfur: Any relaxation in the protection regime are predicted to result in a rapid population decline due to commercial poaching at a rate meeting the threshold for a threatened category. [2]

Many changes have occured on the Tibetan Plateau in the past 30 to 50 years, that have negatively affected Chirus, including an expanding road network, increases in domestic livestock and resulting fencing and grassland degradation, often in the most productive habitats, changing land-use patterns by once exclusively nomadic pastoralists, and large-scale poaching. [3]

 Notably, illegal trade in Chiru hides is an ongoing threat because of the black market for its wool. [1] According to the Chinese government, about 20.000 Chirus were poached annually in the late 1990s, primarily to make shahtoosh shawls and scarves. Black-market bartering, with profit margins approaching 600 percent, often results in movement of bones and other parts of endangered Tigers to Asian markets in exchange for Chiru hides that move illegally into Nepal and India. Legal inroads have been made in thwarting traditional black market routes and worldwide demand for shahtoosh garments, but continued vigilance and education are needed. [3]

 Shahtoosh – one of the most expensive animal fibers: Chiru wool is finer than cashmere and used to make expensive „shahtoosh“ shawls and scarves. They cost 1.000 to 5.000 US Dollar each [3], but may sell for as much as 18.000 US Dollar. Therefore shahtoosh is considered to be one of the most luxurious animal fibers in the world. [1] It takes 3 to 4 Chiru hides to make a single shawl, and the wool cannot be sheared or combed because the fibers are very short and attached to the base of guard hears. [3] Shahtoosh shawls are traditionally called „ring shawls“ because they are so fine that they can be passed through a woman’s wedding ring. [1]

 Reserves: To address the conservation of Tibetan ecosystems, the Chinese government has established an admirable network of reserves. The 300.000 km² Chang Tang National Nature Reserve in north-central Tibetan Plateau is roughly the size of Germany, making it the second largest reserve in the world. Important contiguous reserves to the north in Xinjiang include West Kunlun Reserve (30.000 km²), Mid Kunlun Reserve (32.000 km²), and Arjin Shan Reserve (45.000 km²). Kekexili reserve (45.000 km²) and Sanjiangyuan Reserve (150.000 km²) occur east of Chang Tang in Qinghai, but Chirus only occur in the western part of Sanjianggyuan. This impressive network of reserves is important to the Chiru because migratory populations move north and south between Xizang and Xinjiang and west and east between Xizang and Qinghai. The network currently encompasses about 75 percent of the known migratory routes of Chirus. [3]

Extant populations of Chirus and others are still threatened by human activities, including illegal harvest and competition with domestic livestock, and difficulties with enforcement of protective laws because of limited personnel and the expansive and very remote nature of the Tibetan Plateau. [3]

Trophy hunting

Not a factor today (2018).

Tibetans formerly hunted Chiru on a subsistence basis, principally for food, using traps, dogs and muzzle loading rifles. Chiru were also prized by explorers of the Tibetan highland for its excellent meat and ease of hunting (Bower 1894; Roosevelt and Roosevelt 1926; Sclater and Thomas 1887).

Today the Chiru is a Class I protected species in China, and hunting has been prohibited since the early 1990s (Schaller 1998). It is also protected as endangered in India. Some authors support the idea of introducing sustainable hunting programms, which could offer nomadic pastoralists alternatives to unlimited livestock numbers. [1]

Ecotourism

Mammal watching on the Tibetan Plateau has become popular in recent years. The Chiru is not an outstanding species, that travellers look for, but one of several. Several trip reports mentioning Chirus are available on mammalwatching.com

Literature cited

[1] Damm, Gerhard R. and Franco, Nicolás, 2014: The CIC Caprinae Atlas of the World – CIC International Coucil for Game and Wildlife Conservation, Budakeszi, Hungary in cooperation with Rowland Ward Publications RSA (Pty) Ltd., Johannesburg, South Africa.

[2] IUCN SSC Antelope Specialist Group. 2016. Pantholops hodgsonii. The IUCN Red List of Threatened Species 2016: e.T15967A50192544. http://dx.doi.org/10.2305/IUCN.UK.2016-2.RLTS.T15967A50192544.en. Downloaded on 30 April 2018.

[3] Wilson, D.E. and Mittermeier, R.A. [eds], 2011: Handbook of the Mammals of the World. Vol. 2. Hoofed Mammals. Lynx Edicions, Barcelona.

[4] Groves, Colin and Grubb, Peter, 2011: Ungulate Taxonomy. The John Hopkins University Press.

[5] Castelló, José R., 2016: Bovids of the World – Antelopes, Gazelles, Cattle, Goats, Sheep, and Relatives. Princton University Press.

[6] Leslie, David M. and Schaller, George B., 2008: Pantholops hodgsonii (Artiodactyla: Bovidae), Mammalian Species 817:1–13. www.mammalsociety.org/uploads/Leslie%20and%20Schaller%202008.pdf