Tetracerus quadricornis (Blainville, 1816)

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 592-593

16.

Chowsingha

Tetracerus quadricornis

French: Tétracére / German: Vierhornantilope / Spanish: Antilope de cuatro cuernos

Other common names: Four-horned Antelope

Taxonomy. Cerophorus quadricornis de Blainville, 1816 ,

India.

The Chowsingha is the only wild bovid, indeed mammal, with four horns. The only other member of the tribe Boselaphini , the Nilgai ( Boselaphus tragocamelus ), can be nine times as heavy and twice as tall as the Chowsingha. Despite the size difference, the two species share a similar ancestry and skull and horn-core characteristics. They presently occur sympatrically in India, although numbers and range of the Chowsingha are smaller than the Nilgai. Whether the presence or absence of anterior horns should be used to distinguish subspecies is unclear, because one subspecies may not have these horns. Further complicating matters, males 10-14 months of age that do not yet have anterior horns can be confused with adult males of comparable size. Anterior horns sometimes occur as only hairless raised bumps, making identification in the field difficult. Three subspecies recognized.

Subspecies and Distribution.

T.q.quadricornisdeBlainville,1816—C&NPeninsularIndia.

T:q.iodesHodgson,1847—sub-HimalayanregioninNIndiaandSNepal.

T. q. subquadricornis Gray, 1843 — SC & SW Peninsular India.

Descriptive notes. Head—body 90-110 cm, tail 10-15 cm, shoulder height 55-66 cm; weight 15-25 kg. The Chowsingha is the smallest Asian bovid. Male-only horns, arising from the unique frontal bone of the skull, distinguish the sexes of the Chowsingha at maturity. It is the only wild mammal species with four horns, but the subspecies subquadricornis is said to have only two anterior horns. Aside from the absence of horns in females, mass and general characteristics of the sexes are comparable. The Chowsingha is small and delicately built. Its pelage is thin, short, and paler in summer and thick, coarse, and darker in winter. The color of the Chowsingha’s summer pelage is variable, perhaps among currently described subspecies, from dull rufousred and pale brown to yellow-creamy-fawn. The winter pelage is brown, with paler or whitish ventral and inner leg markings without clear demarcation. There is a white ring and tuft of hair on the lower legs, but sometimes it is not obvious. The muzzle, back of ears, and stripes down the front of the legs are blackish. Occasionally, a pair of white spots occurs on each cheek, similar to the Nilgai. The tail is short and compressed. The Chowsingha has very large elongated preorbital glands and well-developed unguicular glands above false hooves on the rear legs; there are no inguinal glands. The frontal-parietal profile of the skull is slightly and gently rounded, and the occipital meets the parietal at a right angle with very large lachrymal fossae. Mean skull lengths of the three subspecies are 18:7-19. 3 cm. Dental formula is 1 0/3, C0/1,P 3/3, M 3/3 (x2) = 32. The canines are incisoriform. The upper molars are short, with quadrangular crowns and selenodont cusps, and lack additional columns on the inner side. Age classes of male Chowsinghas can be characterized, in general, by their mass and the presence and length of anterior horns: class 1 (young-of-theyear less than 66% of adult body mass); class 2 (juvenile males with no evidence of anterior horns, which start to develop at 10-14 months of age in captivity); class 3 (males with anterior horns less than 33% of the length of the posterior horns); and class 4 (oldest males with anterior horns greater than 33% of the posterior horns). Most male Chowsinghas in Panna National Park, India, had anterior horns 25-66% the length of their posterior horns, but some males had anterior and posterior horns of equal length.

Habitat. The Chowsingha is a habitat generalist but prefers dry deciduous mixed forest with thickets of trees and shrubs (even within open dry patches), hilly terrain, and areas of limited human disturbance. It avoids disturbed areas but tends to use other habitats in proportion to their availabilities. High, grassy vegetation is frequently used and provides protection from predators, which include Tigers (Panthera tigris ), Leopards (P. pardus), and Dholes (Cuon alpinus ); the Chowsingha rarely exceeds 15% of any of those predator’s diets. Despite occupying dry forests, local distributions of Chowsinghas are constrained by daily need for free water.

Food and Feeding. Herbivorous, but given its small size, the Chowsingha is a selective feeder focusing on nutritious plant parts such as fruits, flowers, and fresh leaves. In tame-animaltrials on grazing plots dominated by grasses and forbs in India, Chowsinghas preferred, in descending order, legumes (up to 60%), other herbaceous species, woody species, and grasses, reflecting selection of the most nutritious and digestible forage available. In Gir Forest National Park, India, mixed ungulate assemblages partition their food selection, but all depend on woody species during the hot-dry season. Preference by Chowsinghas for Ziziphus mauritiana, Acacia leucophloea, A. nilotica, and Emblica officinalis, among others, has been documented. Fruits of Emblica and Terminalia are consumed by Chowsinghas and other Indian ruminants.

Breeding. The breeding season likely peaks in June—July, when the chance of observing pairs of females and males is highest. Parturition can occur throughout the year in the wild, but newborns are noted most often in October—November. Few observations of breeding behavior of wild Chowsinghas exist; only two 1-2 second copulatory bouts have been reported. In captivity, mating behavior includes pre-copulatory play, with males and females kneeling on their front knees and facing each other, interlocking their necks and pushing rigorously. Males then display a drill-like strutting behavior before copulation. Age at sexual maturity of wild Chowsinghasis not clearly understood, but two captive females had theirfirst offspring at 21 months of age. The female reproductive tract of the Chowsingha has two uterine compartments separated by a median anterior-to-posterior septum; the fallopian tubes are small relative to those of other ungulates. Four inguinal mammae are present in females. Placental cotyledons number 22-30, about one-half that noted in other antelopes; the fetal chorion has vascular ridges similar to the Eurasian Wild Pig (Sus scrofa). Gestation is about eight months—long for such a small ungulate. Interparturition intervals of one captive female were 285 and 327 days. Of 64 captive births in Paris, France, 59% were twins and 41% were single births, the sex ratio at birth was generally equal, and parturition was extended from August through May. In captivity in native India, average litter size was 1-6, and seven neonates were 0-74—1-1 kg at birth, 42-46 cm in total length, with shoulder heights of 24-27. 5 cm. In the wild, most newborn sightings are of twins, but most subsequent sightings are of single offspring, suggesting regular loss of one offspring. Offspring remain with their mothers for about one year. An adult female can be seen with her young-of-the-year and ajuvenile, presumably hers. Maximum life span of Chowsinghas in captivity is generally about ten years, but one female lived 17 years and five months.

Activity patterns. Little information exists on daily activity patterns. The Chowsingha is likely crepuscular and perhaps active at night. It is secretive and very wary in presentday India. It will often freeze rather than flee when a threat approaches, but it also will make conspicuous leaps followed by quiet stealthy movements. It is easily tamed when young and has been used in feeding trials.

Movements, Home range and Social organization. The Chowsingha is non-migratory, but little is known about its movements and home range. It is likely sedentary, with individuals possibly occupying exclusive home ranges. Densities in India range from 0-2 ind/km? in Gir Forest National Park to 2-7 ind/km? in Panna National Park; no density estimates are available from Nepal. Chowsinghas are shy, non-herding ungulates and occursolitarily or in groups of four or fewer individuals throughout the year. In Nagarhole National Park, India, 80% of observations were of solitary individuals; maximum group size was two. In Gir Forest National Park, India, maximum group size was four but averaged 1-5-1-6 individuals. In Panna National Park, India, 69% of individuals were solitary throughout the year and 24% were in groups of two. Mean group size increased seasonally, but only slightly, from 1-1 in November to 1-6 in May. Adult males segregate from females and subadults during non-breeding times. In Gir Forest National Park, India, male-female ratios were 0-62: 1 in winter and 0-71:1 during the hot-dry season; female:offspring (more than one year old) ratios were 1:0-46 in winter and 1:0-14 during the hot-dry season. Monthly sex ratios in Panna National Park ranged from 0-37: 1 in November to 1:45: 1 in July (annual average is 0-72:1), the larger ratio perhaps reflecting greater visibility of males during the breeding season. Alarm calls are described as a “husky pronk” or sharp bark. Males make a distinct coughing sound around females, and females make soft calls to locate hidden neonates. Male and female Chowsinghas use their large preorbital glands to mark vegetation with scent, leaving a white crystallized film that suggests exclusive home ranges. Both sexes will defecate repeatedly at the same location. Non-random clustering of repeatedly used fecal piles in some areas suggests a form of communication or advertisement, similar to the behavior of the related Nilgai ( Boselaphus tragocamelus ). The use of common defecation sites by Chowsinghas, Nilgai, and Deccan Chinkara ( Gazella bennettii) suggests that the greatest niche separation occurs between Chowsinghas and Deccan Chinkara.

Status and Conservation. CITES Appendix III ( Nepal only). Classified as Vulnerable on The IUCN Red List. The Chowsingha is fully protected under Schedule I of the Indian Wildlife Protection Act. Although it occurs in a large geographic area, it is not abundant anywhere,is considered decreasing throughoutits range, and is largely confined to protected parks and sanctuaries. The total number of Chowsinghas is only about 10,000. Given habitat fragmentation, isolation, and the small sizes of populations of Chowsinghas, loss of genetic diversity is of concern. It is prized as a hunting trophy because of its unique four horns, and poaching may be a localized conservation challenge. Minimizing habitat loss and maintaining connectivity among protected areas are important to the conservation of the Chowsingha.

Bibliography. Acharjyo & Misra (1975a, 1975b), Acharjyo & Mohapatra (1980), Berwick (1974), Blanford (1888), Crandall (1964), Groves (2003), Huffman (2005), Karanth & Sunquist (1992), Khan (1997), Khan et al. (1996), Krishnan (1972), Leslie & Sharma (2009), Lydekker & Blaine (1914), Mallon (2008e), Mauget et al. (2000), Phythian-Adams (1951), Pocock (1910), Prater (1980), Rahmani (2001), Rice (1991), Schaller (1967), Sclater & Thomas (1900), Sharma (2006), Sharma & Rahmani (2004), Sharma et al. (2005), Shrestha (2001), Shull (1958), Weigl (2005), Weldon (1884).

Figures

14. Saola (Pseudoryx nghetinhensis), 16. Chowsingha (Tetracerus quadricornis), 17. Nyala (Nyala angasii)

Subspecies and Distribution. T.q.quadricornisdeBlainville,1816—C&NPeninsularIndia. T:q.iodesHodgson,1847—sub-HimalayanregioninNIndiaandSNepal. T. q. subquadricornis Gray, 1843 — SC & SW Peninsular India .