An ecological survey of the Royal Karnali-Bardia Wildlife Reserve, Nepal. Part II: Habitat/animal interactions

Abstract

The habitat utilisation by ungulates in a newly created tiger sanctuary of the southwestern Nepalese Terai is analysed. While most of the Royal Karnali-Bardia Wildlife Reserve is covered by a rather homogeneous belt of moist subtropical deciduous forest, one section of the reserve supported a wide variety of habitat types. In this area, flood plain, savannah, and several riverine forest associations intergraded with stands of the dominant Shorea robusta forest. Free-living mammals responded to this ecological heterogeneity, permitting an analysis of habitat preferences by the following species: chital Axis axis, nilgai Boselaphus tragocamelus, hog deer Axis porcinus, barking deer Muntiacus muntjak, swamp deer Cervus duvauceli, sambar Cervus unicolor, and two primate species, common langur Presbytis entellus, and rhesus monkeys Macaca mulatta. Differences in feeding and anti-predator strategies offered a degree of ecological separation between most of the ungulates studied. Changes in plant distribution and phenology affected ungulate food habits, energy budgets, movements, and seasonal distribution. A special feeding relationship between certain ungulates and langur and rhesus monkeys was observed. The sambar, an ungulate capable of exploiting a feeding niche in continuous climax forest, appears to be best adapted to the habitat types which dominate most of Karnali-Bardia, while only 30% of the reserve could be considered prime habitat for the chital, the most abundant grazing ungulate in the reserve. Proposals to improve habitat conditions for grazing ungulates through an experimental programme integrating controlled burns, water hole development, and the creation of openings in continuous climax forest are examined.