IUCN/SSC Otter Specialist Group Bulletin

©IUCN/SCC Otter Specialist Group

Volume 40 Issue 1 (January 2023)

Citation: Bida, Y.B. (2023). Notes on Feeding Behaviour of Asian Small-Clawed Otters in Namdapha Tiger Reserve, Arunachal Pradesh, India. IUCN Otter Spec. Group Bull. 40 (1): 39 - 41

Previous | Contents | Next

Notes on Feeding Behaviour of Asian Small-Clawed Otters in Namdapha Tiger Reserve, Arunachal Pradesh, India

Yumlam Benjamin Bida^1*

¹Ashoka Trust for Research in Ecology and the Environment, Regional Office Eastern Himalaya-Northeast India, NH 10, Tadong-737102, East Sikkim, India
*Corresponding Author Email: benjamin.bida@atree.org

OBSERVATION

On 06 March 2020 at 0610hr, while conducting field surveys to monitor White-bellied Herons along river Noa-dehing, near Deban forest camp of Namdapha Tiger Reserve (27° 29' 45'' N, 96° 23' 49'' E; WGS 84; 321 m elev.), we observed a group of four Asian Small-clawed Otters, two adults and two juveniles, preying on fishes. At the time of observation, the raft of otters was seen attempting to catch prey in the shallow waters of the fast-flowing Noa-dehing river, ca. 300m upstream from the point of observation. After 4 mins the raft moved downstream continuing their pursuit of fishing. The adults kept diving into the water, and would remain submerged for ca. 5 secs each time. At 06h15, after five dives in ca. 3 mins, one adult otter was seen emerging out with a fish in its mouth. The fish was later identified as Gara sp. After the catch, it immediately moved on top of a boulder and started consuming the fish, without the use of its claws. It was quick to chew on the fish before any of the other individuals could reach it, and showed no intention of sharing its catch. The head of the fish was consumed first, and later the entire body was chewed as fast as it could. The otter completely consumed the fish in ca. 10 secs (Video at https://doi.org/10.6084/m9.figshare.20066603.v1 ). During this time other individuals in the raft were observed to be still fishing in vicinity. After ca. 3 minutes in that spot, the raft of otters moved downstream into deeper waters, still continuing to dive in search of fishes. At 06h25 all four individuals of Asian Small-clawed Otter came out of the river towards the other side for c. 1 min, and then moved back in to swim upstream still trying to catch a prey. After ca. 5mins of unsuccessful hunt they came back out to the river bank and later moved into the adjacent forest.

On another occasion, at 15h00, on 31 March 2021, while returning back to our base camp, we observed two Asian Small-clawed Otters swimming in the deep waters of Namdapha river, Namdapha Tiger Reserve, Arunachal Pradesh, India (27° 33′ 51″ N, 96° 33′ 3″ E; WGS 84; 533 m elev.) ca. 300m away from the point of observation. The two individuals were observed diving into the river simultaneously for ca. 14 minutes in the fast-flowing stretch of the river where numerous boulders are present. During this period, we observed the otters making 20-25 dives that resulted in no catch. Finally, at 15h15, one of the otters emerged out on a boulder, holding a larger, anterior portion of a fish in its claws. Subsequently, we observed the other otter also with a catch which may have been the smaller portion of the same fish, as it had the posterior half of the fish. The fish was later identified as Tor sp. The uneven sloping surface of the boulder hindered us from getting a clearer view of the second individual consuming its portion of the fish. The first individual with the larger portion of the catch was observed to consume the fish from head first and then towards the pelvic fin. After ca. 25s emerging out from the water the second otter had completely finished consuming its share and was observed to approach the first otter, which could still be seen chewing on its share. As the second otter approached the first, it tried to steal the share of the first otter with an act of aggression showing its canines, to which the first responded by turning away still chewing on its share (Video at https://doi.org/10.6084/m9.figshare.20088614.v1 ). The first otter finished consuming its share in ca. 2 mins, following which the second otter approached it once again and consumed the left-over bones and gut of the fish (Fig. 1). Once the otters were done consuming the fish completely, they rest on the same boulder for ca. 5 mins, after which they dive back into the river at 15h40. After four dives near in the same location, they swam upstream, probably in search of more food. As the otters swam more than 500m away from us, we were unable to observe or photograph them further.

To our knowledge, this is the first report with photographic evidence of Asian Small-clawed Otters feeding on Gara sp. and Tor sp. from their natural habitat. For Asian Small-clawed Otters, even though they are social animals, there is no evidence of cooperative hunting among individuals of this species (Harris, 1968; Kruuk et al., 1993). However, the observations presented in the current report suggests that they do hunt in groups but show little to no intention of sharing their catch with one another.

Acknowledgements: We thank Dr. Sarala Khaling, Regional Director, Ashoka Trust for Research in Ecology and the Environment, Regional Office Eastern Himalaya-Northeast India for all the support and encouragement. This paper would not have been possible without her support. We thank our field assistants namely Ashwini Kumar Chakma, Sunil Kumar Chakma, Lokimoi Chakma and Sanjib Kumar Chakma who have been tirelessly working with us in difficult terrains and unpredictable weather conditions. We would also extend our gratitude towards the officials of Namdapha Tiger Reserve, Department of Forest, Government of Arunachal Pradesh for providing logistical and technical support at times of need. Financial support for fieldwork was provided by the National Geographic Society, [Grant No.: NGS-51179C-18].

REFERENCES

Harris, C.J. (1968). Otters, A Study of the Recent Lutrinae. London. Weidenfeld & Nicolson.
Kruuk, H., Kanchanasaka, B., O'Sullivan, S., Wanghongsa, S. (1993). Niche Separation in Three Sympatric Otters Lutra perspicillata, L. lutra and Aonyx cinerea in Huai Kha Khaeng, Thailand. Biological Conservation 69: 115-120.

Résumé: Notes sur le Comportement Alimentaire des Loutres Cendrées d ’Asie dans la Réserve du Tigre de Namdapha, dans l’Arunachal Pradesh, en Inde
On sait très peu de choses sur les habitudes alimentaires et l’écologie de la loutre cendrée d’Asie (Aonyx cinereus) dans ses habitats naturels, en particulier dans la partie nord-est de l’Inde, où des études poussées sur les loutres cendrées d’Asie et les loutres en tant que groupe, sont en court de réalisation. Nous rapportons ici deux observations indépendantes de loutres cendrées d’Asie se nourrissant de poissons dans les rivières de la réserve du Tigre de Namdapha dans l’Arunachal Pradesh, en Inde.
Revenez au dessus

Resumen: Notas sobre el Comportamiento Alimenticio de la Nutria de Uñas Pequeñas Asiática en la Reserva de Tigres Mandapha, Arunachal Pradesh, India 
Se sabe muy poco acerca de los hábitos alimenticios y la ecología de la Nutria de Uñas Pequeñas Asiática (Aonyx capensis) en sus hábitats naturales, especialmente en la parte nor-oriental de la India, donde aún están pendientes de realizarse estudios intensivos sobre las Nutrias de Uñas Pequeñas Asiáticas y sobre las nutrias como grupo. Aquí informamos dos observaciones independientes de Nutrias de Uñas Pequeñas Asiáticas predando sobre peces en los ríos de la Reserva de Tigres Mandapha, en Arunachal Pradesh, India.
Vuelva a la tapa

Previous | Contents | Next