Smooth-coated otters do not negatively affect humans.
Saltwater crocodiles and other crocodile species are the most likely predators of smooth-coated otters. Other potential predators are medium-sized cat species and large birds of prey (primarily on young otters). Smooth-coated otters are agile in the water and on land and use their sensitive whiskers to detect water disturbances. They are also social animals, with each animal in a group contributing to vigilance efforts.
Known Predators:
Smooth-coated otters are the largest otters in southeast Asia. They weigh from 7-11 kg as adults and can be up to 1.3 m long. Their fur is shorter and smoother than other otters, and appears velvety and shining. They have short tightly packed under fur and longer water repellant guard hairs. The under fur measures 6-8mm, the guard hairs are 12-14 mm long. The fur is light to dark brown dorsally, and light brown to almost gray ventrally. Smooth-coated otters are distinguished from other otters by their rounder heads, prominent naked noses, and flattened tails. Their noses resemble an upside down v, or a distorted diamond. Like other otters, they have webbed feet and strong dexterous paws that are armed with sharp claws.
Range mass: 7 to 11 kg.
Range length: 1 to 1.3 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
The oldest known smooth-coated otter in captivity died at 20 years and five months. The typical lifespan in the wild is between 4 and 10 years, although no conclusive studies have been made. It is suggested that the mortality rate of smooth-coated otters is correlated with the abundance of fish. Smooth-coated otter populations follow fish populations in the Tarai areas of the upper Gangetic plains in India and Nepal. Following the monsoon season, smooth-coated otters move into flooded swamp areas to take advantage of fish population booms. The otters breed there and when the swamps shrink and the fish return to the permanent rivers so do the otters.
Range lifespan
Status: captivity: 20 (high) years.
Typical lifespan
Status: wild: 4 to 10 years.
Smooth-coated otters are mostly found in lowlands, coastal mangrove forests, peat swamp forests, freshwater wetlands, large forested rivers, lakes, and rice paddies. Although adapted for water, smooth-coated otters are equally comfortable on land and can travel long distances overland in search of suitable habitat. They shelter in shallow burrows and piles of rocks or driftwood. Some build permanent burrows near water with an underwater entrance and a tunnel that leads to a chamber above the high-water line, much like American beaver. In Malaysia smooth-coated otters are more abundant in mangrove forests than in river systems.
Habitat Regions: temperate ; freshwater
Terrestrial Biomes: forest
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools
Wetlands: swamp
Other Habitat Features: riparian
Smooth-coated otters are a Palearctic and Oriental species. They are found throughout much of southern Asia, from India eastward. There is also an isolated population found in the marshes of Iraq. Evidence shows that the range and population of smooth-coated otters is shrinking due to loss of habitat and intensive trapping.
Biogeographic Regions: palearctic ; oriental
Smooth-coated otters are omnivorous and will eat insects, earthworms, crustaceans, frogs, water rats, turtles, large birds, and fish. Fish make up 75 to 100% of the diet. Smooth-coated otters frequently hunt in groups, driving schools of fish together for easy capture. Fishermen in India and Bangladesh use this group hunting behavior to train them to herd fish into nets. A group of otters has a feeding territory of 7 to 12 square kilometers. A single adult consumes about 1 kg of food per day in captivity.
Animal Foods: birds; mammals; amphibians; reptiles; fish; eggs; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
Smooth-coated otters impact aquatic vertebrate and invertebrate communities via predation.
Like other otters, smooth-coated otters are trapped for fur. Although not as luxurious as its North American cousin, the river otter, or the sea otter, the pelage of smooth-coated otters is used for garments, adornments, and other items. Trained smooth-coated otters are used by fisherman to herd fish into nets.
Positive Impacts: body parts are source of valuable material
Smooth-coated otters are listed as vulnerable on the IUCN Red list. The population is threatened by loss of wetland habitats to large-scale hydroelectric projects, settlements and agriculture, poaching, and contamination of waterways by pesticides. Smooth-coated otters are protected in India under the Wildlife (Protection) Act, 1972, and are listed as endangered. They are also listed under schedule II, and listed in Appendix II of CITES.
US Federal List: threatened
CITES: appendix ii
IUCN Red List of Threatened Species: vulnerable
Like other carnivores, smooth-coated otters use scent for inter and intra specific communication. They have a pair of scent glands at the base of the tail, which they use to mark vegetation, flat rocks, or shorelines near feeding areas. This marking behavior in otters is called sprainting. In areas where the smooth-coated otter, European otter, and small-clawed otter occur together, sprainting occurrs in different areas by each species. Sprainting sites in small-clawed otters are usually high on the bank on flat rocks. Sites for smooth-coated otters are more prominent than those of small-clawed otters. Sprainting sites of European otters are lower on the bank and less frequent than that of other otters.
Smooth-coated otters also use visual cues, such as body postures, touch, and auditory cues in communicating with conspecifics.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Smooth-coated otters form strong monogamous pairs. Although males are larger, it is females that dominate the pair.
Mating System: monogamous
No conclusive studies have been made on reproductive timing in smooth-coated otters. Where otters are dependent on monsoons for precipitation, they are most likely to breed between August and December. In the Delhi Zoo, all matings occurred in the month of August. The gestation period is 61-65 days. Smooth-coated otters give birth to and raise their young in a burrow or shelter near water, which they excavate, or they assume an abandoned one. The cubs disperse at about 1 year of age. Sexual maturity is reached at two years.
Breeding interval: Breeding occurs once yearly.
Breeding season: Breeding occurs from August to December.
Range number of offspring: 2 to 5.
Range gestation period: 61 to 65 days.
Average weaning age: 130 days.
Average age at sexual or reproductive maturity (female): 2 years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average number of offspring: 5.
Two to five cubs are born in a litter, blind and helpless. At thirty days, the cub's eyes open, and by sixty days, they can swim. The young are weaned at about 130 days. Unlike other otters, smooth-coated otters form small family groups consisting of a mated pair with up to 4 offspring from previous seasons. The male is allowed to join the group after the cubs are weaned, and he helps provide the cubs with food.
Parental Investment: altricial ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents
The smooth-coated otter (Lutrogale perspicillata) is an otter species occurring in most of the Indian subcontinent and Southeast Asia, with a disjunct population in Iraq. It is listed as Vulnerable on the IUCN Red List since 1996 and is threatened by habitat loss, pollution of wetlands and poaching for the illegal wildlife trade.[1] As its name indicates, its fur is smooth and shorter than that of other otter species.
The smooth-coated otter has a short and sleek fur that is dark to reddish brown along the back, but light brown to almost grey on the underside. It is distinguished from other otter species by its more rounded head and a hairless nose in the shape of a distorted diamond. Its tail is flattened, in contrast to the more rounded tails of other otters. Its legs are short and strong, with large webbed feet bearing strong claws. It is a relatively large otter, from 7 to 11 kg (15 to 24 lb) in weight and 59 to 64 cm (23 to 25 in) in head-body length, with a tail 37 to 43 cm (15 to 17 in) long. Females have two pairs of teats.[2]
Lutra perspicillata was the scientific name proposed by Isidore Geoffroy Saint-Hilaire in 1826 for a brown otter collected in Sumatra.[3] Lutrogale was proposed as generic name by John Edward Gray in 1865 for otters with a convex forehead and nose, using perspicillata as type species.[4] In the 19th and 20th centuries, several zoological specimens were described, including:
The smooth-coated otter is the only living species in the genus Lutrogale. Three subspecies are recognised:[2]
The smooth-coated otter groups with the Asian small-clawed otter and the African clawless otter into a sister clade to the genus Lutra. The smooth-coated otter and the Asian small-clawed otter genetically diverged about 1.33 ± 0.78 million years ago. Hybridisation of smooth-coated otter males with Asian small-clawed otter females occurred in Singapore. The resulting offspring and their descendants bred back into the smooth-coated otter population, but maintained the genes of their small-clawed otter ancestors. Today, a population of at least 60 hybrid otters exists in Singapore.[9]
The smooth-coated otter is distributed in Pakistan, India, Nepal, Bhutan, Bangladesh, southern China, Myanmar, Thailand, Vietnam, Malaysia, Singapore, and on Borneo, Sumatra and Java. An isolated population lives in the marshes of Iraq.[1] It has often been recorded in saltwater near the coast, especially on smaller islands, but requires a nearby source of freshwater.[10] It inhabits areas where fresh water is plentiful such as wetlands, seasonal swamps, rivers, lakes and rice paddies. Where it is the only occurring otter species, it lives in almost any suitable habitat. But where it is sympatric with other otter species, it avoids smaller streams and canals in favour of larger water bodies.[2] Smooth-coated otter groups studied in the Moyar River preferred rocky areas near fast flowing river segments with loose sand and little vegetation cover.[11]
The population in the Mesopotamian Marshes was feared to have perished, but otter tracks were found in 2009, suggesting the population may have survived.[12] Skins of smooth-coated otters were found during surveys between 2005 and 2012 in the vicinity of Hammar and Hawizeh Marshes. Tracks and scat found in Erbil Province were also thought to have been left by smooth-coated otters.[8]
In Gujarat, smooth-coated otters were documented near lakes, canals and mangroves in the outskirts of Surat in 2015.[13] In Singapore, smooth-coated otters have adapted well to urban environments, and have been observed to use urban structures like gaps under buildings as alternatives for holts. They also use staircases and ladders to get in and out of concrete canals with vertical or near‐vertical banks.[14] This population is well-protected and steadily increasing, with some families, such as the Bishan otter family, becoming a common sight and attracting media attention.[15]
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The smooth-coated otter lives in groups of up to 11 individuals. They rest on sandy riverbanks and establish their dens under tree roots or among boulders. Observations in Peninsular Malaysia indicate that they are active foremost during the day, with a short rest during midday. They mark their playground by urinating and sprainting on rocks or vegetation.[16][17]
They communicate through vocalisations such as whistles, chirps, and wails.[2]
Smooth-coated otters were observed to forage on river banks among tree trunks.[16] They feed mainly on fish including Trichogaster, climbing gourami and catfish. During the rice planting season, they also hunt rats in rice fields. Snakes, amphibians and insects constitute a small portion of their diet.[18] Especially in areas where they share habitat with other otter species, they prefer larger fish, typically between 5 and 30 cm (2.0 and 11.8 in) in length.[10][19]
In Kuala Selangor Nature Park, an otter group was observed hunting. They formed an undulating, slightly V-shaped line, pointing in the direction of movement and nearly as wide as the creek. The largest individuals occupied the middle section. In this formation, they undulated wildly through the creek, causing panic‑stricken fish to jump out of the water a few metres ahead. They suddenly dived and grasped the fish with their snouts. Then they moved ashore, tossed the fish up a little on the muddy part of the bank, and swallowed it head‑first in one piece.[20]
Smooth-coated otters form small family groups of a mated pair with up to four offspring from previous seasons.[21] Copulation occurs in water and lasts less than one minute.[22]
As long as the food supply is sufficient, they breed throughout the year, but where they depend on monsoon precipitation, they breed between October and February. The largest recorded wild-born litter of seven pups was observed in Singapore in November 2017.[23] Pups are born after a gestation period of 60 to 63 days, with a usual litter size of up to five pups. The mothers give birth to and raise their young in a burrow near water. They either construct such a burrow themselves, or they take over an abandoned one. At birth, the pups are blind and helpless, but their eyes open after 10 days. They are weaned at about three to five months and reach adult size at about one year of age, and sexual maturity at two or three years.[2]
The smooth-coated otter is threatened by poaching, loss and destruction of wetlands, as these are converted for settlements, agriculture and hydroelectric projects; water courses are being polluted by pesticides such as chlorinated hydrocarbons and organophosphates. These factors lead to a reduced prey base. Otters are indiscriminately killed especially at aquaculture sites. Trapping of otters is prevalent in India, Nepal, and Bangladesh.[1]
Along the Chambal River in India, smooth-coated otters are most vulnerable during winter when they rear young. During this season, they are disturbed by humans harvesting crops and removing wood along rocky stretches of the river.[24]
Six juvenile smooth-coated otters were discovered in a bag left at Bangkok airport in January 2013. This was the first case of smooth-coated otters thought to have been destined for the illegal pet trade.[25] At least seven smooth-coated otters were offered for sale through websites by traders in Thailand and Malaysia between 2016 and 2017.[26]
The smooth-coated otter is a protected species in most range countries and listed globally as a vulnerable species. It had been listed on CITES Appendix II since 1977.[1] Since August 2019, it is included in CITES Appendix I, thus strengthening its protection in regards to international trade.[27]
In southern Bangladesh, smooth-coated otters are used for commercial fishing. They are bred in captivity and trained to chase fish into fishing nets. By 2011, this fishing technique was used by about 300 fishermen, with an additional 2,000 people indirectly dependent on the technique for their livelihood.[28]
The smooth-coated otter (Lutrogale perspicillata) is an otter species occurring in most of the Indian subcontinent and Southeast Asia, with a disjunct population in Iraq. It is listed as Vulnerable on the IUCN Red List since 1996 and is threatened by habitat loss, pollution of wetlands and poaching for the illegal wildlife trade. As its name indicates, its fur is smooth and shorter than that of other otter species.
