Diet Analysis of Barking Deer (Muntiacus Vaginalis, Boddaert 1785) in Nagarjun Forest of Shivapuri Nagarjun National Park,Nepal

Abstract

The composition and selection of food by ungulates is a fundamental element to understand their dietary habits. This study aimed to assess the winter diet composition, niche breadth, and preference of forage plants for Barking Deer in the Nagarjun Forest of Shivapuri Nagarjun National Park, Nepal in 2019. The line transect method along with quadrat sampling was used for the collection of Barking Deer pellets and reference plant species. Micro-histological technique was used to prepare micro-photographs of reference food plants and deer pellets in the laboratory. A total of 1500 fragments of 50 fecal samples were analyzed to identify undigested plant parts in the pellet of Barking Deer. Diet composition was expressed in terms of percentage of occurrence, Levin’s niche breadth was calculated for the evaluation of the degree of food selectivity and browse to grass ratio to determine whether the Barking Deer adopts browsing or grazing strategy. Food preference of Barking Deer was evaluated by using Ivlev’s Electivity Index and statistical tool, Chi-square test was used for data analysis. Barking Deer consumed 26 plant species. Of these, 18 species belonged to browse, four species to grass, two species to fruits, and two other species to fern and herb. The contribution of browse species was higher in the overall diet (61.13%), followed by fruits (16.66%), grasses (10.87%), and others (1.87%). Smilaxaspera (10.33%), Litsea chartacea (7.87%), Schima wallichii (5.4%), Prunus cerasoides (5.13%), etc. were the other major browse plants in the diet. Choerospondiasaxillaris (15.86%) formed the largest proportion of all the food species and was the important fruit for Barking Deer. The important grass species present in the diet were Imperata cylindrica (4.13%) and Carex sp. (3.2%). The Browse to grass ratio in the Barking Deer diet was 5.62 showing a strong preference towards the browse plants. The niche breadth of the food plants consumed by Barking Deer was found to be 0.512 indicating its generalist nature of feeding, consuming a variety of species. Choerospondias axillaris (IEI = 0.5), Litsea chartacea (IEI = 0.51), Prunus cerasoides (IEI =0.5) and Smilax aspera (IEI = 0.51) were four plant species found to be strongly preferred. Castanopsis indica, (IEI = 0.07),Myrica esculenta (IEI = 0.05) and Berberis asiatica (IEI = 0.04) were found to be used in proportion to availability whereas Rhododendron arboreum (IEI = -0.58), Pinus roxburghii (IEI = -0.7), Lithocarpus elegans (IEI = -0.6), etc. were some other avoided food plants. Researches on nutritive value of important dietary species and their niche overlap with other herbivore competitors are recommended. xv