Behavioural ecology of four-horned antelope ( Tetracerus quadricornis de Blainville, 1816) in the tropical forests of southern India

Abstract

Four-horned antelope is one of the smallest Asian bovids, endemic to India and Nepal. Despite its wide distribution in India, the species has received very little scientific attention. We studied its habitat preference, activity budget, diet, social behaviour and breeding in Mudumalai Wildlife Sanctuary. Among tropical dry deciduous and thorn forests, where the species is distributed, higher abundance was observed in dry deciduous areas (0.26 individuals/km, 95% CI = 0.22–0.29) especially the short grass habitat associated with stunted and sparse tree growth known as ‘tree-savanna’ than the dry thorn forest (0.09 individuals/km, CI = 0.001–0.18). The antelopes follow a bimodal feeding pattern with 52% morning (06:00–10:00 h) and 65% evening (14:00–18:00 h) devoted to feeding. Diet was studied by analyzing 59 pellets collected from two major habitat types during the dry season. Of the 52% of the diet components identified, grass (28.6%, 14 species) and browse biomass (23.3%, 10 species; with five herbs (9.6%), one shrub (5.6%) and leaves and fruits from four trees (8.2%)) constituted equal parts indicating a mixed feeder category. Mean group size of 1.5 (±0.71 SD range: 1–4) individuals estimated from 94 direct sightings with solitary individuals (62%) and adult with fawn/s (11%) constituting over 70% of the sightings indicating a non-herding nature of the species. Newborns were sighted from February to May with a peak during April and the reported gestation period of c. 8 months suggests mating taking place during June–August. Mean litter size was 1.6 (±0.53 SD, n = 9). The study suggests the need for including dry thorn forest habitats of Sigur plateau in the existing protected areas and detailed studies for long-term conservation of the species in this region.