UCN/SSC Otter Specialist Group Bulletin

Volume 42 Issue 1 (January 2025)

Citation: Shrestha, M.B., Shrestha, G., Dangaura, H.L., Chaudhary, R., Shrestha, P.M., Dewan, K., Sada, R., Savage, M., and Zuofu Xiang (2025). Confirmation of the Presence of Asian Small-Clawed Otter Aonyx cinereus in Nepal after 185 Years. IUCN Otter Spec. Group Bull. 42 (1): 3 – 8

Confirmation of the Presence of Asian Small-Clawed Otter Aonyx cinereus in Nepal after 185 Years.

Mohan Bikram Shrestha1*, Ganga Shrestha2, Hiru Lal Dangaura3, Rajeev Chaudhary4, Purna Man Shrestha2, Karun Dewan5, Rajesh Sada5, Melissa Savage6, and Zuofu Xiang1

_1College of Forestry, Soil and Water Conservation, Central South University of Forestry and Technology, Changsha, Hunan, China
2Wildlife Research and Education Network, Tokha, Kathmandu, Nepal
3Bird Conservation Nepal, Lazimpat, Kathmandu, Nepal
4Division Forest Office, Dadeldhura, Nepal
5WWF-Nepal
6University of California, USA
*Corresponding Author Email: shrmohan5@gmail.com

Received 1st December 2024, accepted 5th December 2024

Abstract: The Asian Small-clawed Otter has not been observed in Nepal since 1839. Because of a lack of evidence of the species over such a prolonged period, it has been sometimes suggested that it is extinct in the country. Here, we present the first photographic evidence of Asian Small-clawed Otter in Nepal in 185 years. In November 2024, a juvenile Asian Small-clawed Otter was captured at the confluence of Rangun Khola and Puntara Khola of Dadeldhura District in far-western Nepal, was nurtured in the Forest Office for a week before released to the wild. The presence of a juvenile otter implies the presence of other otter individuals in the area. This rare observation is a significant confirmation of the species presence in Nepal and warrants detailed study and conservation initiatives to conserve the species.
Keywords: Asian Small-clawed Otter, rediscovery, Rangun Khola, Puntara Khola, Nepal

INTRODUCTION

Nepal has been said to be home to three species of otters, smooth-coated otter (Lutrogale perspicillata), Eurasian Otter (Lutra lutra) and Asian Small-clawed Otter (Aonyx cinereus) (Acharya and Rajbhandari, 2011). Confirmed evidence for the presence of Small-clawed Otters in Nepal has been lacking since the mid-19th century. The Asian Small-clawed Otter was last reported by Hodgson in 1939 (Hodgson, 1839). The Smooth-coated Otter has been the most studied Otter species of Nepal. Studies on Eurasian Otter is gaining momentum in recent years. The species’ status was ambiguous for decades till was observed in the Barekot, Roshi and Tubang Rivers (Shrestha et al., 2021), in the Pelma River (Shrestha et al., 2022) and in area of Kathmandu Valley (Shrestha et al., 2023). In contrast, Asian Small-clawed Otter have not been recorded in Nepal; for more than a century and a half since 1839 (Acharya et al., 2023). Only anecdotal records from Nepal were in from Makalu Barun National Park, Kailali and Kapilvastu Districts (Jnawali et al., 2011). Globally categorized by the IUCN as Vulnerable (Wright et al., 2021) and listed as Data deficient species in National Red List Assessment of Mammals of Nepal (Jnawali et al., 2011). Deficient information on Asian Small-clawed Otter made its status in Nepal indeterminate (Jnawali et al., 2011).

OTTER SIGHTING SITE AND SPECIES IDENTIFICATION

In November 2024, a juvenile Asian Small-clawed Otter was sighted at the river junction of the Rangun Khola and its feeder stream the Puntara Khola at Parsuram Municipality-12 of Dadeldhura District in far-western Nepal (29.132819˚N 80.335374˚ E; 401m asl) (Fig. 1). Downstream, the Rangun Khola flows into the Mahakali River (also called as Sarada River) and then into the Karnali River in India.

Figure 1. Location map of Asian Small-clawed Otter capture.

Morphological characteristics and species identification of the otter in photographs and videos confirmed as an Asian Small-clawed Otter by IUCN Otter Specialist Group members (Fig. 2). The species has front paws with reduced nails, well adapted for catching small vertebrate and invertebrate prey in shallow and murky water (Hussain et al., 2011; Nicole Duplaix, pers. comm.). The juvenile otter was captured by a local, transferred to the nearby Sub-division Forest Office and nurtured for a week before released to the wild. The Forest Officer (co-author) shared photographs and videos with otter researchers in Nepal (primary author) for species identification, which was further forwarded to IUCN Otter Specialist Group members for the confirmation.

Figure 2. Asian Small-clawed Otter (Photograph: Rajeev Chaudary)

HABITAT NOTE

A brief habitat study was carried out 1-km upstream and downstream from the otter sighting location as a baseline for future study. The habitat characterstics of four sites were noted: the otter observation location, 1-km upstream at the Rangun Khola and at feeder stream the Puntara Khola, and 1-km downstream in the Rangun Khola (Fig. 3). The location of the otter sighting was close to the human settlements Katar and Jogbudha. The bank-to-bank river width varied from 235-750m, but the river itself was shrunken due to the marked reduction of post-monsoon flow, with a tranquil flow and shallow depth. The riverbank was composed of large stones (˃10cm-0.5m), small stones (1-10cm) and sand and mud with higher cover of large stones. The bank vegetation cover was sparse with small patches of Imperata cylindrica and Chromolaena odorata. The otter was observed at the edge of leasehold forest, where mining of stone and sand, washing, bathing and fishing activities were common.

Figure 3. Sites of Asian Small-clawed Otter observation site (red circle) and habitat studies (green circle).

CONCLUSION

The sighting of an Asian Small-clawed Otter after 185 years is a remarkable discovery for conservation in Nepal, ending concerns that the species may have been extinct in the country. The sighting highlights the need for detailed study of the status of this species in Nepal and urgent implementation of conservation initiatives. Small-scale mining of construction materials from local rivers, primarily the Puntara Khola is likely to increase in the near future, with substantial impact on aquatic life. The traditional fishing practices using net casting, fishing hooks, draining water, and trapping fish in rice paddies are common. Besides, fishing using poison and explosives have been increasing. These activities will cause a decline in fish populations. Deforestation, habitat degradation, overgrazing, non-point source pollution and agricultural run-off are additional threats to the aquatic life in the area. There are five micro-hydro plants in the Rangun Khola with impacts to the aquatic biodiversity (USAID, 2018). Otters are resilient to highly modified anthropogenic landscapes (Lee, 1996; Theng and Sivasothi, 2016), flexible in habitat selection (Aadrean et al., 2010; Weinberger et al., 2016) and able to recover from low numbers (Marcelli and Fusillo, 2009; Uscamaita and Bodmer, 2010). Nevertheless, given the rare occurrence of Small-clawed Otter in Nepal, mitigation measures are urgently needed for conservation of the species int this region. National otter survey, scientific studies of ecology and phylogeny of the species and conservation measures at priority sites are called for. Nepal has shown an exemplary effort in the conservation of megafauna, resulting in significant population increases of species such as rhinoceros and tigers. A timely conservation effort for this exceptionally rare species, a keystone aquatic mesocarnivore is now urgently needed in Nepal.

Acknowledgments - Authors are grateful to the Sub-Division Forest Office and Division Forest Office of Dadeldhura for their support providing data. We are grateful to residents of Jogbudha and Katar, Dadeldhura for further information. We thank Nicole Duplaix, IUCN Otter Specialist Group Co-chair for the identification of the Asian Small-clawed Otter from photographs and videos.