Lutrogale perspicillata

Geographic Range

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 palearctic
• oriental oriental

Habitat

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 temperate
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• temporary pools

• Wetlands
• swamp swamp

• Other Habitat Features
• riparian riparian

Physical Description

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.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

Smooth-coated otters form strong monogamous pairs. Although males are larger, it is females that dominate the pair.

• Mating System
• monogamous 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.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

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 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

Lifespan/Longevity

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.

Behavior

Smooth-coated otters frequently hunt in groups, driving schools of fish together for easy capture. A group of otters has a feeding territory of 7-12 square km.

• Key Behaviors
• terricolous
• fossorial fossorial
• natatorial natatorial
• motile motile
• sedentary sedentary
• territorial territorial
• social social

Communication and Perception

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 visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

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.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• fish
• eggs
• mollusks
• terrestrial worms
• aquatic or marine worms
• aquatic crustaceans

Predation

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.

Ecosystem Roles

Smooth-coated otters impact aquatic vertebrate and invertebrate communities via predation.

Economic Importance for Humans: Positive

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

Economic Importance for Humans: Negative

Smooth-coated otters do not negatively affect humans.

Conservation Status

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.

Additional Links

Encyclopedia of Life

Contributors

Timothy White (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

References

Chanin, P. 1985. The Natural History of Otters . New York, New York: Facts on File Inc..

Hussain, S., B. Choudhury. 1997. Distribution and Status of the Smooth-Coated Otter Lutra perspicillata in National Chambal Sanctuary, India. Biological Conservation , 80: 199-206.

Hussain, S. No Date. "Status of Otter Consevation in India" (On-line ). Accessed 12/3/02 at http://www.wii.gov.in/envhome/envisdec99/p92-97.htm .

IUCN, 2002. "2002 IUCN Red List of Threatened Species" (On-line ). Accessed 11/29/02 at http://www.redlist.org/search/details.php?species=12427 .

Kruuk, H. 1995. Wild Otters . New York, New York: Oxford University Press.

Mason, C., S. Macdonald. 1986. Otters Ecology and Conservation . New York, New York: Cambridge University Press.

Nowak M, R. 1991. Walker's Mammals of the World . Baltimore: John Hopkins University Press.

Amblonyx Otter Site. 2002. "Characterisics (Lutrogale perspicillata)" (On-line ). Amblonyx Otter Site. Accessed 11/27/02 at http://www.amblonyx.com/otter/perspicillata/otter_char.htm .

Otternet. 2002. "Species Profile: India Smooth-Coated Otter" (On-line ). Otternet. Accessed 11/27/02 at http://otternet.com/species/asiaotter.htm .