Smooth-coated otter | |
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In Borneo, Malaysia | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Carnivora |
Family: | Mustelidae |
Genus: | Lutrogale |
Species: | L. perspicillata |
Binomial name | |
Lutrogale perspicillata (I. Geoffroy Saint-Hilaire, 1826) | |
Smooth-coated otter range | |
Synonyms | |
Lutra perspicillata |
The smooth-coated otter (Lutrogale perspicillata) is a freshwater otter species from regions of South and Southwest Asia, with the majority of its numbers found in Southeast Asia. It has been ranked as "vulnerable" on the IUCN Red List since 1996, as it is threatened by habitat loss, pollution of wetlands and poaching for the illegal wildlife trade. [1] As the common name indicates, its fur is relatively smooth, and somewhat shorter in length than that of other otter species.
The smooth-coated otter has a short, sleek coat of dark-brown to reddish-brown fur along its back, with lighter grayish brown on its underside. It is distinguished from other otter species by a more "rounded" head, and by having a vaguely diamond-shaped, hairless nose. The tail is flattened, in contrast to the more rounded or cylindrical tails of other otters. The legs are short and strong, with large, webbed feet bearing strong and sharp claws for handling slippery fish. The smooth-coated otter is a relatively large otter species, weighing from 7–11 kg (15–24 lb) and measuring around 59–64 cm (23–25 in) in head-body length with a 37–43 cm (15–17 in) long tail. Females have two pairs of teats with which they nurse small litters of several young. [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 the generic name by John Edward Gray in 1865 for otters with a more convex forehead and nose, using perspicillata as the type species. [4] By the 19th and 20th centuries, several early zoological specimens were described, including:
The smooth-coated otter is the only living species in the monotypic genus Lutrogale. Three regional subspecies are currently recognised: [2]
The smooth-coated otter, together with the Asian small-clawed otter and the African clawless otter, form 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 has occurred in Singapore. The resulting offspring and their descendants then bred back into the smooth-coated otter population, but maintained the genes of their small-clawed otter ancestors. Today, an urban 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]
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 International 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]
Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among other animals.
Gavin MaxwellFRSL FZS FRGS was a British naturalist and author, best known for his non-fiction writing and his work with otters. He wrote the book Ring of Bright Water (1960) about how he brought an otter back from Iraq and raised it in Scotland. The otter was of a previously unknown sub-species which was subsequently named after Maxwell. Ring of Bright Water sold more than a million copies and was made into a film starring Bill Travers and Virginia McKenna in 1969.
The Asian small-clawed otter, also known as the oriental small-clawed otter and the small-clawed otter, is an otter species native to South and Southeast Asia. It has short claws that do not extend beyond the pads of its webbed digits. With a total body length of 730 to 960 mm, and a maximum weight of 5 kg (11 lb), it is the smallest otter species in the world.
The Eurasian otter, also known as the European otter, Eurasian river otter, European river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia and Maghreb. The most widely distributed member of the otter subfamily (Lutrinae) of the weasel family (Mustelidae), it is found in the waterways and coasts of Europe, many parts of Asia, and parts of northern Africa. The Eurasian otter has a diet mainly of fish, and is strongly territorial. It is endangered in some parts of its range, but is recovering in others.
The giant otter or giant river otter is a South American carnivorous mammal. It is the longest member of the weasel family, Mustelidae, a globally successful group of predators, reaching up to 1.8 m. Atypical of mustelids, the giant otter is a social species, with family groups typically supporting three to eight members. The groups are centered on a dominant breeding pair and are extremely cohesive and cooperative. Although generally peaceful, the species is territorial, and aggression has been observed between groups. The giant otter is diurnal, being active exclusively during daylight hours. It is the noisiest otter species, and distinct vocalizations have been documented that indicate alarm, aggression, and reassurance.
The Neotropical otter or Neotropical river otter is an otter species found in Mexico, Central America, South America, and the island of Trinidad. It is physically similar to the northern and southern river otter, which occur directly north and south of this species' range. Its head-and-body length can range from 36–66 centimetres (14–26 in), plus a tail of 37–84 centimetres (15–33 in). Body weight ranges from 5–15 kilograms (11–33 lb). Otters are members of the family Mustelidae, the most species-rich family in the order Carnivora.
Aonyx is a genus of otters, containing three species, the African clawless otter, the Congo clawless otter, and the Asian small-clawed otter. The word aonyx means "clawless", derived from the prefix a- ("without") and onyx ("claw/hoof").
The hairy-nosed otter is a semiaquatic mammal native to Southeast Asia and one of the rarest and least known otter species. It is threatened by loss of natural resources and poaching.
The spotted-necked otter, or speckle-throated otter, is an otter native to sub-Saharan Africa.
Endangered mammals of India are the mammal species in India that are listed as threatened in the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Animals
The African clawless otter, also known as the Cape clawless otter or groot otter, is the second-largest freshwater otter species. It inhabits permanent water bodies in savannah and lowland forest areas through most of sub-Saharan Africa. It is characterised by partly webbed and clawless feet, from which their name is derived. The word 'aonyx' means clawless, derived from the prefix a- ("without") and onyx ("claw/hoof").
Lutrogale was proposed as generic name by John Edward Gray in 1865 for otters with a convex forehead and nose, using the smooth-coated otter L. perspicillata as type species.
The Mesopotamian Marshes were drained in Iraq and to a smaller degree in Iran between the 1950s and 1990s to clear large areas of the marshes in the Tigris-Euphrates river system. The marshes formerly covered an area of around 20,000 km2 (7,700 sq mi). The main sub-marshes, the Hawizeh, Central, and Hammar marshes, were drained at different times for different reasons.
The Central or Qurna Marshes are a large complex of wetlands in Iraq that, along with the Hawizeh and Hammar marshes, make up the Mesopotamian Marshes of the Tigris–Euphrates river system. Formerly covering an area of around 3000 square kilometres, they were almost completely drained following the 1991 uprisings in Iraq and have in recent years been reflooded.
The Cauvery Wildlife Sanctuary is a protected area located in the Mandya, Chamarajanagar and Ramanagar districts of Karnataka, India. The Cauvery River passes through its midst. An area of 510.52 km2 (197.11 sq mi) was established as Cauvery Wildlife Sanctuary on 14 January 1987 under Section 18 of the Wildlife Protection Act 1972 with the objective of providing protection, conservation and development of Wildlife and its environment. The sanctuary was expanded to its current area of 102,753 hectares in 2013. On its east, it adjoins Dharmapuri forest division of Tamil Nadu state.
Otter fishing is a fishing technique which uses trained otters to fish in rivers. This method has been practised since the 6th century in various parts of the world, and is still practiced in southern Bangladesh.
The Cape clawless otter is a subspecies of African clawless otter found in sub-Saharan Africa near permanent bodies of freshwater and along the seacoast. It is the largest of the Old World otters and the third largest otter after the giant otter and the sea otter.
The Cretan otter(Lutrogale cretensis) is an extinct otter that was endemic to Crete during the Pleistocene.