Frogs from the Darjeeling Hill Region, India: Elucidation of their morphology and habitat

Abstract

The Darjeeling Hill Region (DHR) comprises the hilly areas of Darjeeling and Kalimpong districts in West Bengal, India. It’s an important part of the Himalayas biodiversity hotspot and is renowned for its enormous biodiversity and enchanting natural beauty. It has variations in altitude, vegetation, temperature, and rainfall. Mainly, the structure and composition of the habitat change along the altitudinal gradients. The enormous biodiversity in the DHR includes several frog species. Frogs play a vital role in the ecological food chain and are an efficient indicator of environmental health. Abundant information is available on the frogs from southern India, however, frogs from the DHR are less studied. Therefore, this study for the first time intends to enlist and examine major frog species from the DHR using morphological tools and documentary evidence. Additionally, detailed accounts of their habitat are elaborated. The survey was conducted from 2020 to 2023 mostly in rainy seasons. Nine species of frogs belonging to seven genera and four major families (Dicroglossidae, Ranidae, Rhachophoridae, and Megophryidae) were observed in the DHR. These frogs were mostly spotted in forests, hill streams, and bushes including tea plants. Interestingly, a well-segregated niche was observed for most of the frogs. Upon comparison, some frogs had slightly variable morphology that may be attributed to their adaptation to specific habitats and prey selection. This work serves as a baseline study and aims to bridge the existing gap in understanding the Indian frog diversity and is expected to aid in framing guidelines for their conservation. © Zoological Society, Kolkata, India 2025.