The hairy-nosed otter (Lutra sumatrana) is a semiaquatic mammal endemic to Southeast Asia and one of the rarest and least known otter species. It is threatened by loss of natural resources and poaching.
|Hairy-nosed otter range|
The hairy-nosed otter has a short brown fur that becomes paler on the belly. Its rhinarium is covered with short hair. Its upper lip and chin are whitish. Some individuals are reddish-chestnut in colour. Its body is long, its tail slender, and its fully webbed paws have prominent claws. Head-to-body length ranges from 57.5 to 82.6 cm (22.6 to 32.5 in), tail length from 35 to 50.9 cm (13.8 to 20.0 in), and weight from 5 to 8 kg (11 to 18 lb). Its skull is flatter than that of smooth-coated otter, and it has smaller teeth. Its forepaws are 5.8 cm (2.3 in) wide and smaller than the hind paws with about 6.6 cm (2.6 in).
The hairy-nosed otter is the least known of the Asian otters, and is also the most difficult to identify in the field. In most other respects, it is similar to the European otter (Lutra lutra).
Distribution and habitatEdit
This hairy-nosed otter occurs in Southeast Asia from southern Thailand, Cambodia, southern Vietnam and Peninsular Malaysia to Sumatra and Borneo. The species is under constant threat of poaching and possibly extinct in India, Myanmar, and Brunei.
In Thailand, it was recorded in the Pru Toa Daeng peat swamp forest and in areas around the Bang Nara river. It mainly habits lowland flooded forests with climaxing vegetation in three levels: a primary forest zone, a secondary forest zone made up of Melaleuca cajuputi, and a third zone of grasslands. These tiers make the habitat hard to penetrate, providing protection from human disturbance and cover from predators. The Bang Nara river habitat, where communities have been discovered, is tidal. The two reserves in Vietnam are both peat swamp forests, surrounded by 15m high Melaleuca cajuputi, covered in dense lianas such as Stenochlaena palustris in its primary zone, and a second zone of meadows made up of Eleocharis dulcis. These two Vietnamese reserves contain many canals and floating aquatic plants like Eichhornia crassipes, Pistia stratiotes, Salvinia cucullata and Ipomoea aquatica to hunt and play in, with surrounding rice paddies as a third buffer zone.
In Vietnam, it was sighted and recorded by camera traps in U Minh Thuong National Park in 2000, where also spraints were found with fish scales and remains of crabs. In 2008, it was also recorded in U Minh Ha National Park.
In Sabah, historic records date to the late 19th century. In 2010, one individual was recorded for the first time by a camera trap in Deramakot Forest Reserve incidentally. In 2016, several individuals were sighted in Tabin Wildlife Reserve.
Ecology and BehaviorEdit
The hairy-nosed otter occurs in coastal areas and on larger inland rivers, solitary or in groups of up to four. Its diet includes fish, such as walking catfish, snakeheads, and climbing perch, and water snakes, mollusks, and crustaceans. During the dry season, individuals forage in drainage canals and ponds.
Pairing of a male and a female may be limited to the breeding period. The contact call between otters is a single-syllabic chirp. Adult females call to pups with a staccato chatter. Not much is known about its breeding habits. Populations in the Mekong Delta possibly breed in November and December, and in Cambodia between November and March. The gestation period lasts around two months. A family of both parents and cubs were sighted between December and February.
Foraging is the main food-acquisition technique due to increased variation in monsoonal patterns in recent years due to global climate change.
The hairy-nosed otter is the rarest otter in Asia, most likely verging on extinction in the northern parts of its range and of uncertain status elsewhere. Only a few viable populations remain, widely scattered in region. The species is threatened by loss of lowland wetland habitats, hunting for fur and meat, and accidental killing during fishing.
In June 2008, the Wildlife Alliance-led Wildlife Rapid Rescue Team received a donated hairy-nosed otter caught near Tonle Sap. Working with Conservation International, they established a safe home for the rescued otter at the Phnom Tamao Wildlife Rescue Centre, but the otter, which had been frequently sick throughout its life in captivity, died of unknown causes in February 2010. Phnom Tamao Wildlife Rescue Centre rescued another hairy-nosed otter in July 2010, and hope it will become part of a future captive breeding program. This is currently the only known hairy-nosed otter in captivity.
- Aadrean, A.; Kanchanasaka, B.; Heng, S.; Reza Lubis, I.; de Silva, P.; Olsson, A. (2015). "Lutra sumatrana". The IUCN Red List of Threatened Species. IUCN. 2015: e.T12421A21936999. doi:10.2305/IUCN.UK.2015-2.RLTS.T12421A21936999.en. Retrieved 30 October 2018.
- Wozencraft, W.C. (2005). "Order Carnivora". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 532–628. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Wright, L.C., Olsson, A. and Kanchanasaka, B. (2008). "A Working Review of the Hairy-Nosed Otter (Lutra sumatrana)". IUCN Otter Specialist Group Bulletin. 25 (1): 38−59.CS1 maint: Uses authors parameter (link)
- Anderson, J. (1878). "Lutra sumatrana, Gray". Anatomical and zoological researches: comprising an account of the zoological results of the two expeditions to western Yunnan in 1868 and 1875; and a monograph of the two cetacean genera, Platanista and Orcella. Second Volume − Plates. London: Bernard Quaritch. pp. Plate X.
- Payne, J.; Francis, C. M.; Phillipps, K. (1985). A field guide to the mammals of Borneo. Kota Kinabalu, Sabah, Malaysia: Sabah Society. ISBN 9679994716. OCLC 21150449.
- Kanchanasaka, B. K. (2001). "Tracks and Other Signs of the Hairy-Nosed Otter (Lutra sumatrana)". IUCN Otter Specialist Group Bulletin. 18 (2): 57–63.
- Kanchanasakha, B.K. (2007). "Food Habitats of the Hairy-nosed Otter (Lutra sumatrana) and the Small-clawed Otter (Amblonyx cinerea) in Pru Toa Daeng Peat Swamp Forest, Southern Thailand". Presentation at Xth International Otter Colloquium. Hwacheon, South Korea.
- Lekakul, B.; McNeely, J. (1977). Mammals of Thailand. Laprao, Thailand: Kurusaphra Press.
- Poole, C. M. (2003). "The first records of Hairy-nosed Otter Lutra sumatrana from Cambodia with notes on the national status of three other otter species" (PDF). Natural History Bulletin Siam Society. 51 (2): 273–280. Retrieved 12 July 2016.
- Nguyen, X. D.; Pham, T. A. & Le, H.T. (2001). "New Information about the Hairy-Nosed Otter (Lutra sumatrana) in Vietnam". IUCN Otter Specialist Group Bulletin. 18 (2): 64–75.
- Willcox, D., Bull, R., Nguyen V. N., Tran Q. P. and Nguyen V. T. (2017). "Small carnivore records from the U Minh Wetlands, Vietnam". Small Carnivore Conservation (55): 4–25.CS1 maint: Multiple names: authors list (link)
- Lubis, R. (2005). "First Recent Record of Hairy-Nosed Otter in Sumatra, Indonesia". IUCN Otter Specialist Group Bulletin. 18 (1): 14–20.
- Ishigami, J., Ambu, L.N., Tuuga, A. and Tsubouchi, T. (2017). "The second recent record of Hairy-nosed Otter (Lutra sumatrana) in Sabah, Malaysia" (PDF). IUCN Otter Specialist Group Bulletin 34 (2): 67−72.CS1 maint: Multiple names: authors list (link)
- Nguyen, X.D., Pham, T.A. and Le, H.T. (2001). "New Information about the Hairy-Nosed Otter (Lutra sumatrana) in Vietnam". IUCN Otter Specialist Group Bulletin. 18 (2): 64−75.CS1 maint: Uses authors parameter (link)