Diversity, Abundance and Distribution of Small Mammals in Forest Patches of Kathmandu Valley, Nepal

Abstract

In Nepal, researches on small mammals are mainly conducted in unaltered habitats such as national parks, high altitudinal forests and grasslands, located far from human settlements. However, forest patches in urban environments also have potentiality for supporting small mammals, providing them with shelter, resources and space for breeding. This study was aimed at exploring diversity, abundance and distribution of small mammals in forest patches of Kathmandu valley. Three sites were selected for the study namely Ranibari community forest, Swayambhunath hillock and Coronation garden. Methods employed were Direct Observation, Roost Survey and Line Transect. Field survey was conducted in June-July, 2019. In selected sites, 250 m transect was established and 25 live traps (Local, Sherman and Tube) were set for capturing species. Trapped individuals were measured, marked and released at the site. Data were analyzed by using MICROSOFT EXCEL 2010, PAST and CANOCO. From a survey of 625 trap nights, 61 individuals representing six species, three orders and four families were identified. Abundance was higher from Ranibari Community Forest having rich floristic constituent. Asian house shrew (Suncus murinus) was the most dominant species. Shannon Weiner diversity index revealed moderate diversity (1.26). Diversity pattern was clumped in study areas owing to uneven distribution of resources in natural environment. Species response to five environmental parameters showed significant relation in Ranibari community forest (F=2.446, P=0.018) and Coronation garden (F=2.75 P=0.05), whereas it was insignificant in Swayambhunath hillock (F=1.60 P=0.17). These results suggested that small mammals in urban forest patches were influenced by ground cover, distribution of resources and environmental parameters. Therefore, research on small mammals is suggested to be conducted in other forest fragments in Kathmandu Valley.