Isotopic evidence for dietary niche overlap between barking deer and four-horned antelope in Nepal

Autor: Pokharel, Krishna Prasad, Yohannes, Elizabeth, Salvarina, Ioanna, Storch, Ilse
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Journal of Biological Research
ISSN: 2241-5793
1790-045X
Popis: Background Morphologically similar sympatric species may have a high degree of niche overlap. Barking deer Muntiacus vaginalis and four-horned antelope Tetracerus quadricornis are solitary ungulates of the Indian sub-continent. Limited information is available regarding their trophic ecology, particularly of the endemic four-horned antelope. We present stable carbon (δ13C), nitrogen (δ15N), and sulphur (δ34S) isotopic values, and nitrogen content (%N) of faeces from barking deer and four-horned antelope living in lowland Nepal to assess trophic niche differentiation of these herbivores along the browser-grazer continuum. We also describe trophic differences between those two species in ecological niches and seasonal effects on their diets. Results We found that the barking deer and four-horned antelope consumed C3 plant sources exclusively. The niche partitioning in their diet was reflected by δ34S values. Some seasonal effects observed were: δ13C and δ15N were significantly lower in the dry season diet of four-horned antelope than that of barking deer, while δ34S values were significantly higher in the winter diet; monsoon diet was similar for both species. Faecal N levels for barking deer and four-horned antelope were similar throughout all the seasons, indicating that both species adapted their feeding behaviour so as to maximize protein intake, in accordance with season and environment. Conclusions Barking deer and four-horned antelope both are browsers; their dietary sources overlapped during monsoon but differed during the dry season. Conservation actions focused on resource management during the dry season to reduce food scarcity and competition over limited resources is likely to be the most effective. Electronic supplementary material The online version of this article (doi:10.1186/s40709-015-0029-0) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
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