Spatial Niche Partitioning in Sub-Tropical Solitary Ungulates: Four-Horned Antelope and Barking Deer in Nepal

Abstract

Differential resource use allows a diversity of species to co-exist in a particular area by specializing in individual ecological niches. Four-horned antelope Tetracerus quadricornis is endemic to the Indian subcontinent and has a restricted distribution in Nepal and India; however, the barking deer Muntiacus vaginalis is relatively common throughout its wide distribution range. We wanted a better understanding of their habitats and how these two similarly sized solitary ungulates manage to coexist in lowland Nepal. We used fecal pellet belt transect surveys in the Babai valley, Bardia National Park to study the habitat associations of both species. We found empirical evidence that four-horned antelope prefer hill sal forest and deciduous hill forest at higher elevations, whereas barking deer preferred riverine and sal forest in lower elevations. We found a clear niche differentiation of four-horned antelope and barking deer that made the coexistence of these similarly sized solitary ungulates possible. Hence, resource partitioning is the key to coexistence of these solitary ungulates, and the fine-grained habitat mosaic of different forest types in the study landscape appears to be the underlying feature. Therefore, maintaining the habitat mosaic and preserving valuable hill sal and deciduous hill forests will facilitate the coexistence of herbivores in sub-tropical regions.

Predicting potential distribution of poorly known species with small database: the case of four‐horned antelopeTetracerus quadricornison the Indian subcontinent

“…; Pokharel et al. ). The representation of the FHA's distribution in environmental space by higher temperature of warmest months (bio5) and lower precipitation of driest month (bio17) suggests that the species can geographically be found in areas with hot and long dry season.…”

“…; Pokharel et al. ), we expected that bioclimatic variables, which are related to a savannah‐like vegetation, can explain the distribution of FHA. We believe that the findings of this study will fill the knowledge gap regarding the distribution and status of the species; in particular, our findings will be helpful to ground truth potential occurrences, and to assess habitat conditions.…”

“…() and three from Nepalese protected areas: “Bardia,” “Banke,” and “Chitwan,” which are also known to harbor FHA (Pokharel et al. ; http://www.dnpwc.gov.np assessed on 2 December 2015). Thus, we obtained 57 FHA records.…”

“…; Pokharel et al. ), a comprehensive and empirical assessment of the FHA's distribution range is still lacking (Krishna et al. ; Leslie and Sharma ).…”

“…Studies at local scale extents suggest that FHA occurrence is determined by tree species richness (Sharma et al 2013) and their nutrient levels (Ahrestani et al 2011). However, beside local explanations of the specieshabitat relationships (Krishna et al 2008;Baskaran et al 2009;Sharma et al 2013;Pokharel et al 2015), a comprehensive and empirical assessment of the FHA's distribution range is still lacking (Krishna et al 2009;Leslie and Sharma 2009).…”