Habitat and Ecology
The hairy nosed otter principally predate on fish (85.5%) followed by water snake and they also supplement their diet with frog, lizard, turtle, crab, mammal and insect, although these may not be that important in its diet (Kanchanasaka 2007). Fish belonging to the families Channidae, Belontiidae, Anabantidae, Notopteridae, Synbranchidae, Clariidae, Nandidae, were identified in the fecal samples from Thailand. The main prey selected were three-spot gourami (Trichogaster trichopterus), common climbing perch (Anabas testudineus), and snakeheads (Channa sp) (Kanchanasaka 2007).
Not much is known about its breeding behaviour but there is indication that it breeds in November-December in the Mekong delta. Kanchanasaka et al. (2003) found that gestation was around 2 months as with other otters, and cubs were seen in December to February, and one family observed consisted of both parents and a cub.
IUCN Red List Assessment
Red List Category
Red List Criteria
- 2004Data Deficient
- 2000Data Deficient
- 1996Vulnerable(Baillie and Groombridge 1996)
- 1994Insufficiently Known(Groombridge 1994)
- 1990Insufficiently Known(IUCN 1990)
- 1988Insufficiently Known(IUCN Conservation Monitoring Centre 1988)
In recent years, the tropical peat swamp forests are under severe threat due to fire and other anthropogenic activities such as plantation for oil palm, food crops such as rice, corn and soyabean, and fish farming. In Viet Nam the entire Mekong Delta has been converted into rice fields reducing the habitat of otter and other wildlife species into few pocks. In Malaysia, fire reduced 70% of the Binsulok Forest Reserve and 10% of the Klias Forest Reserve. This has affected the surrounding environment and the biodiversity. In Indonesia over the last 20 years, the ecosystem has been reduced from almost 30 million hectares to only about 15 million hectares, and most of what remains has already been logged selectively. Such levels of habitat modification have profound effect on the native biodiversity.
In its entire range the hairy-nosed otter is under increasing pressure due to intensive poaching (Yoxn 2007). In Cambodia, around the Tonle Sap Lake, poaching of otters and other wildlife are common practice (Somanak 2007). In Viet Nam otters are hunted for illegal wildlife trade, and also for meat and medical use. Similar is the case in other range countries.
The principal threat to the fauna of Southeast Asian region is the burgeoning human population, and resultant biomass demand which puts pressure on natural resources. Unavailability of adequate prey species and suitable undisturbed habitat are putting additional pressure on all wildlife species including hairy-nosed otter.
The hairy-nosed otter (Lutra sumatrana) is one of the rarest otter species on earth. Until 1998, it was thought to have been extinct, but small populations have been discovered since then.
- Weight: 11 to 13 pounds (5.0 to 5.9 kg)
- Head-body length: 20 to 32 inches (51 to 81 cm)
- Tail length: 14 to 20 inches (36 to 51 cm)
The hairy-nosed otter is the least known of the Asian otters, and is also the most difficult to identify in the field. The hairy-nosed otter gets its name from the hairs on the end of its rhinarium (moist part of its nose); in most other respects it is similar to European otter, Lutra lutra. Hairy-nosed otters are entirely brown, except for lips, chin and upper throat, which are whitish. Their fur is rather rough but short. Their tails are flattened and oval in cross section, and their feet are fully webbed between the digits, with prominent claws. The penis of the adult male is not visible externally. The contact call between otters is a single-syllabic chirp; adult females call to pups with a staccato chatter. Large otters are very similar and can be positively distinguished only by close inspection of the nose and fur, or the skull. In this species, the skull is flatter than that of smooth otter, Lutrogale perspicillataI and has smaller teeth.
Ecology and habitat
The hairy-nosed otter can be found in coastal areas and on larger inland rivers, solitary or in groups of up to four. Its diet includes fish and crustaceans. Pairing of a male and a female may be limited to the breeding period.
Distribution and status
This otter is found in Southeast Asia (Myanmar, South Thailand, Cambodia, South Vietnam and Peninsular Malaysia, including Sumatra and Borneo). Extremely few individuals survive in Vietnam, southern Thailand, Sumatra and Cambodia, being menaced by poaching.
At present, it is believed to live mainly in two nature reserves in Vietnam, in the Toa Daeng peat swamp forest in southern Thailand, and in Sumatra, the place for which it was named. It was rediscovered in 2005. It was also rediscovered in Tonle Sap Lake, Cambodia. Even from these places, they are known from a tiny number of sightings and some roadkill, and from skins.
In June 2008, the Wildlife Alliance -led Wildlife Rapid Rescue Team received a donated hairy-nosed otter originating near the Tonle Sap in Cambodia. 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.
Another record of the species was on September 2008 in U Minh Ha National Park in southern Vietnam, when researchers from the Carnivore and Pangolin Conservation Program said they have found two hairy-nosed otters.
After being assumed to be “nonexistent” in the state of Sabah, Malaysia for the last 100 years, the otter was rediscovered using a series of camera traps in 2010. The same study also confirmed the presence of several other endangered species. Director of Sabah Forestry Department Datuk Sam Mannan said, “These findings show that long-term sustainable forest management is of great importance for the protection of some of this country’s most threatened species and of the unique biodiversity of the forests of Borneo.”
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.Although the population of the hairy nosed otter is unsure it is supposedly around 86.
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- Vanar, Muguntan (2010-07-26) Endangered otter resurfaces in Sabah. thestar.com.my