Four-horned antelope

The four-horned antelope (Tetracerus quadricornis), also called chousingha, is a small bovid antelope native to central, South and Western India, along with a smaller population in Nepal. The sole member of the genus Tetracerus, the chousingha was first scientifically described in 1816 by French zoologist Henri Marie Ducrotay de Blainville. Three regional subspecies are currently recognised. The four-horned antelope has a yellowish-tan, sometimes reddish or goldenrod coat. It is slender with thin legs and a short tail. It stands nearly 55–64 cm (22–25 in) at the shoulder and weighs about 17–22 kg (37–49 lb). Its four horns are unique among antelopes and distinguish it from most other bovids. The longer pair of straight, spike-like horns is atop its head between the ears, while the other, shorter pair is on the forehead; its posterior horns are always longer than the anterior horns, which may even present as merely fur-covered "studs". While the posterior horns measure 8–12 cm (3.1–4.7 in), the anterior ones are usually 2–5 cm (0.79–1.97 in) long.

The four-horned antelope is diurnal (active mainly during the day) and typically solitary by nature, though some antelope may form loose groups of three to five animals, usually one or more adults, possibly accompanied by calves. This elusive antelope feeds on grasses, herbs, shrubs, foliage, flowers and fruits. It needs to drink water frequently; as such it stays in places near water sources. The breeding behaviour of the four-horned antelope has not been well studied. The age at which they reach sexual maturity and the season when mating occurs have not been understood well. Gestation lasts about eight months, following which one or two calves are born. They are kept concealed for the first few weeks of their birth. The young remain with the mother for about a year.

Four-horned antelopes tend to inhabit areas with significant grass cover or heavy undergrowth, and avoid human settlements or the presence of dogs. Once more common throughout deciduous forests in India, the four-horned antelope now occurs in disjunct, fragmented populations, with genetic "bottlenecking" (e.g. inbreeding) becoming a potential threat to the stability of future populations that do not intermingle during mating seasons. The four-horned antelope is threatened by the loss of its natural habitat due to agricultural expansion. Because of its four-horned skull and its horns it was historically a target for trophy hunters. It is presently listed as "vulnerable" on the IUCN Red List.

The scientific name of the four-horned antelope is Tetracerus quadricornis. The generic name Tetracerus is the combination of two Greek words: tetra meaning "four" and keras meaning "horn". The specific name quadricornis is derived from two Latin words: quattuor meaning "four" and cornu "horn". The four-horned antelope is known by several vernacular names: chausingha, chowsingha, chousingha (Hindi for "four horns"), doda, ghutri (mainly in central India) (Hindi); kondu kuri (Kannada); chauka (Nepalese); nari komboo marn (Tamil).

The four-horned antelope is the sole member of the genus Tetracerus, and is placed under the family Bovidae. The species was first described by French zoologist Henri Marie Ducrotay de Blainville in 1816. The four-horned antelope has only one other relative in the tribe Boselaphini, the nilgai (Boselaphus tragocamelus). The Boselaphini have horns with a keel on the front and lack rings as found in other antelope groups.

The authority for Tetracerus is variously indicated according to interpretations of the International Code of Zoological Nomenclature. The name was first published in an 1825 publication by English naturalist Thomas Hardwicke but cited the English zoologist William Elford Leach – probably by an editor – as the authority in a footnote at the end of the publication. Philip Sclater and Oldfield Thomas listed Hardwicke as the genus authority by virtue of his being the author of the publication. However, Leach is now identified as the appropriate authority based on Article 50.1.1 of the Zoological Code.

A 1992 phylogenetic study showed a strong possibility of a clade consisting of Boselaphini, Bovini and Tragelaphini. Bovini consists of the genera Bubalus, Bos, Pseudoryx (saola), Syncerus (African buffalo), Bison and the extinct Pelorovis. Tragelaphini consists of two genera: Taurotragus (eland) and Tragelaphus. Boselaphini and Tragelaphini were predicted to be close; this was seconded by a similar study in 1999. The following cladogram is based on the 1992 study:

Colin Groves (2003) recognizes three subspecies of the four-horned antelope on the basis of distribution and physical characteristics such as coat colour, body size and the number of horns: