An ecological survey of the Royal Karnali-Bardia Wildlife Reserve, Nepal: Part III: Ungulate populations

Abstract

Population density and biomass estimates for wild and domestic ungulates in the Royal Karnali-Bardia Wildlife Reserve, Nepal, are presented and compared with values obtained from other reserves in South Asia. Wild ungulate population densities varied in relation to habitat diversity; large herbivores were most numerous where early and intermediate successional stages intergraded with one another and only sparsely distributed in continuous climax sal Shorea robusta forest. Chital Axis axis was the most abundant wild ruminant in the reserve. It and the nilgai Boselaphus trago-camelus constituted 88% of the total wild herbivore biomass in the southwestern corner of Karnali-Bardia, where an intensive study was carried out. The biomass of domestic stock utilising the same study area in 1975 was computed to be 15–17 times higher than the levels attained by wild ungulates in April of 1977, nearly two years after the reserve borders had been closed to domestic grazing. Observations during the hot-dry season indicated that both wild and domestic ruminants competed for the same forage species. Among the wild ungulates, chital were decidedly the most gregarious, commonly associating in feeding aggregations of over 20 individuals on the open savannahs. Nilgai and wild boar Sus scrofa formed smaller groups while barking deer Muntiacus muntjak and hog deer Axis porcinus were primarily solitary. Chital exhibited a peak in rutting activity during the late hot-dry season and a subsequent birth peak in February. Nilgai exhibited a different pattern, breeding in January and calving during the monsoon, when optimum foraging conditions prevailed.