Diet composition and niche overlap of sympatric anurans in cropland and forest of western side of Barandabhar corridor forest,Nepal

Abstract

Dietary variation in sympatric anurans is important for understanding ecological niche of a species which have allowed it to live in various habitats and ecosystems. Croplands are crucial for amphibians that are useful for farmers by controlling crop pest and frogs also play vital role in forest ecosystem as well. Hence, this study aimed to focus on dietary habits and niche overlap of anurans in cropland and forest of western side of Barandabhar Corridor Forest, Central Nepal. Nocturnal time constrained visual encounter transect survey using 100 m long

transect at least 250 m

apart from 19.00 to 21.00 hr was used for the anuran survey during monsoon (JuneAugust). Non-lethal stomach flushing technique was applied for the extraction of diet

and analyzed microscopically. Twenty nine (22.83%) individuals out of 127 stomachs

flushed

were found with empty stomach. The diet contained 442 prey items which were further categorized into 16 taxonomic groups. Hymenoptera (62.89%) was highly abundant prey, followed by Coleoptera (10.40%) and Anurophagy (6.78%). The relation between weight of prey uptake was significantly correlated with the Snout-Vent Length (SVL) (R 2 =0.399, p<0.0001). Similarly, dietary preferences was no significant with habitat types (t =0.08, p=0.931). The result of Non-metric Multidimensional Scaling revealed that there was high degree of dietary niche overlap between the anurans species in both cropland and forest habitat. Common Asian Toad had the highest niche breadth (BA = 0.42) and high dietary niche overlap (0.985) followed by Minervarya teraiensis (average SVL= 46.13) and Duttaphrynus melanostictus (average SVL= 63.68 mm). This study evaluated the dietary preferences in different habitats and indicated importance of anurans. Hence, this study will be baseline for the conservation of amphibians.