A Life On the Brink Of Extinction
Smooth Coated Otters of Cauvery River
“Ambassadors of wetlands”
Ecology, Behaviour and Conservation.
A K Singh IFS,
Dept of Forest & Ecology, Karnataka, India
Smooth Coated Otter called as Lutrogale perscipillata is known to occur in more than a couple of thousands of numbers in Cauvery Wild Life Sanctuary. These Smooth Otters are highly charismatic and popular animals of high concern to fishermen, naturalists, scientists and wild life conservationists the world over. Otters have an intrinsic beauty and they are exciting. Smooth Otters, one of the most intriguing semi aquatic mammals, habitual of living amphibious lifestyle, both in water and nearby lands are celebrated for living a life of mystery, disguise and concealment15. A life on the brink of extinction. Otters need to be noticed to undertake stiff protection, taking practical steps for preventing decimation of endemic populace going from “Vulnerable” under “Red List” of IUCN to endangered with each passing day. Contiguity of riparian vegetation, incessant rows of rocky crevices, indiscreet river side stony dens, persistent sheltering holts of embankments and tiny islands amidst river flourishing with bushes and grasses are required to be shielded from external injury. Any further extirpation of ideal shelter of this “indicator of clean environment” and “sign of hygiene” of water ecosystems will entail arriving at a “tipping point of no return”. Rapidly increasing activities of fishing, capricious industrial effluence, in descript contamination of water, unrestrained littering of river banks and “off the cuff” commercial-ecotourism are the factors causing outrageous annihilation of potential refuge of these fast vanishing inhabitants along the vast stretch of Cauvery River, pushing them to the “brink of extinction” with each passing moment. An existence cliff hanging on the precipice.
Prologue:
It was a spring season of 2011. We were in a mood to encounter otters on one nightfall at Cauvery riverside. We hurled an igloo tent on the beach of sand dunes of mosale-madu near alambadi tribal village at gopinatham. Apart from this, dodmaralu, ganemati, arakalkada, mutatthi, galibore, basvankada, savarimathi, ugania, rashimadu, bhimankal all along the Cauvery river too are called to be the ideal natural habitat of
smooth coated otters in the sanctuary. Moments were gathering sundown one by one. Sky was getting filled with carroty clouds sparkling reflectance of twilight stretching all over in the atmosphere. Flow of the river water was gentle, slow and meanderingly sluggish with no rapids around. Banking upon the river shore is living a life of beauty and splendour. River banks were standing with queue of robust woods of Terminalia and tamarinds. Few crepuscular blood hound creatures wild in nature, with the advent of evening, started appearing with Indian eagle owl in a fit of quiver, scuttle and scamper from one tree to another as we boulevard through. Sun was diving under horizon and shimmering with Couple of Smooth Coated Otter at Bhimankal, Palar in a barking pose near the rocks and stream. Pristine, virgin islands mid of the river are the ideal habitat of Smooth Coated Otter in Cauvery WLS. paint brush dying sky as murky as orange. It was getting a bit darker, dim and sinister. Entire panorama of the landscape was turning from daylight to orange all over. It was a game time for evening mortals and night creepers thereafter. I opted to stay in the igloo tent tonight deep in the dark jungle risking life for everybody accompanying, as the „rendezvous select‟ was the “vantage point” both for me and for the herds of elephants who routinely visit for water sip. Two large herds of them were almost near behind us. Riparian river forests were getting crammed with ominously menacing resonance of nocturnals like fish eagle, shikra, hawks and kites. A deep „whom whom‟ an undulating curree voice of brown fish owl surfacing from old dead wood branches started haunting the background. Tamil fishermen have pervaded every inch of their side of river bank lodging upon almost all sand dunes with their coracles and fishnets with no stone left unturned. Fishing seems to be a good business across the river. This side I was vigil over noisy, strangely high pitched squealing ka ka keee raptor like voice of grey hornbill taking a sway in a flurry from terminalia. That side of the river I was untiringly occupied in a gape to observe kingfisher sounding „chow chow kila‟. My associate whispered in me to target our gawk at darker looking otter crawling over sand beach on the other bank of the river near the rocky boulder beaches. Smooth coated otter was crawling mesmerizingly over the sands. All of us stood spell bound for a moment. Looking through binocular its fur appears to be greyish velvety, shining and smoother. They are reported to have short tightly packed under fur and longer water repellent guard hairs. The under fur measures 6-8mm, the guard hairs are 12-14 mm long. Smooth-coated otters are the largest otters in south east Asia. They weigh from 7-11 kg as adults and can be up to 1.3 m long. The fur seemed 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. We took coracle boat ride 6 pm at bhimankal upstream palar. 5 to 6 smooth otters appeared propping up head on above the river water surface. Their noses resemble an upside down v, or a distorted diamond. We could sense the presence upto almost 20 otters including direct sightings in a patch of only two kilometres here near palar...
Distribution:
Smooth-coated otters are top carnivore of wetland ecosystems18. They are mostly found in lowlands, coastal mangrove forests, peat swamp forests, freshwater wetlands, large forested rivers, lakes, and rice paddy fields7. But here across big rocky boulders of bhimankal towards confluence of palar and Cauvery river we walked along number of crevices in the rocks, could see plenty of holts on the lands and detected colossal rate of rocky dens, boulder couches at far greater length along the river line. It was swampy forests with taste of stuarine to which number of water streams were contributing to the junction of two rivers. Backwaters of mettur dam inundate the river waters upto hoganekal forming a deluge of stagnant swamps and quagmire of marshlands stretching across for almost 20 km. Adapted for water, smooth-coated otters are equally comfortable on land and can travel long distances overland in search of suitable habitat6. They shelter in shallow burrows and piles of rocks or driftwood found on the water body or river. Some build permanent burrows near water with an underwater entrance and a tunnel that leads to a chamber above the high-water line17. Network of tunnel underground is hardly known to anyone. Vast expanse of swamp forests acts as conundrum of mystery trails of night blood hounds. Among 13 species of Otters only 3 species reported to have been found in India. Lutra lutra in north India, Amblonyx cenerius and Lutrogale perscipillata in South India17. Like other otters, they have webbed feet and strong dexterous paws that are armed with sharp claws to hunt fish. Smooth-coated otters form strong monogamous pairs18. Although males are larger, it is females that dominate the pair. When we traversed tiny islands in the middle of the river from hoganekal upstreams, to our amazement they were found to permanently establish holts near banks of islands mid river. We could observe the underwater entrance at few places which progresses underground tunnel that leads to a nest above the water. Smooth otters use scent glands at the base of the tail used to mark lands, rocks, vegetation near feeding areas in a behaviour known as sprainting.
We observed number of spraints on the red granite rocks of bhimankal on the entire stretch upto 2 km. Small broken bones of fishes, birds, frogs appeared to be present in the spraints on entire vast expanse here and there on the rocky strata. Smooth otter seems to love bushy thickets, non stop unbroken dense vegetation along the banks and of course, it finds irresistible the contiguous rocky shelter with sand dunes over the entire stretch of river line2. It loves to live on pristine virgin tiny islands which occur plenty in the middle of the river free from human disturbance. We traversed across few mid river islands in ugania where fresh pugmarks were writ large in trails over the surface of the sand dunes8. Spraints were found plenty hither and thither amid the grassy sands on the islands. In one of the study by Koushalya Shinoy Centre of Ecological Sciences, Indian Institute of Sciences Bangalore 2004 at Muthathi, five of the sand sites holts were found, of which two were not being used and one was used infrequently observed. All the holts were dug in loose sand on the riverbanks. They were heavily marked with spraints at the entrance. Thick vegetation cover, mainly the grass Arundo donax, surrounded each entrance27. One was dug under the roots of the tree Diospyros montana. Size of the entrances varied from 28 to 130 cm in width and 20 to 51 cm in height. All holts found were located mostly on islands which are generally found mid river. Such islands are preferred generally in order to avoid human and livestock disturbance.
Behavior:
In another incident at Bhimankal, one dark large cormorant flies in front of me with a long pointed wings. It follows the waves at some height above, while I yacht on coracle boat slow and steady against a rock on the embankment. The bird slows, circles then forms into a pointed projectile, rocketing down. The waters part with a dramatic splash, the cormorant flaps then bobs to the surface, giving no clues as to whether it has captured a fish or not. I am so absorbed by the shag that several minutes pass before I notice a pair of otter, just in front of us in the river weed barking like a dog at us with khar kharr sounds. One staring at us upright standing with two forelimbs hanging and another anchoring rocks sitting and visible from lateral side drying the wet fur. Perhaps it would have been a call for frightening us away. They are sometimes seen with a flash of white which are quite often fishes. Like a cat with a mouse, it is reported to play with the prey. The otter grab fish shakes, lets go again, waits a second, darts after it, grabs itagain. The otter rolls on to its back, holding the fish in its mouth and paws, then the fish wriggles off again and the otter pounces upon it. So it goes on for eight minutes, until the predator has had enough of the game, lands the fish and eats every scrap of it15. Catching fish in water is difficult exercise for an otter. 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. Close to alambadi near mosalemadu and near Singapore colony at bhimakal there are many lochs in line on Cauvery river here the people see smooth coated otter climbing on to the granite rocks, diving beneath it, and emerging with an eel, frog in its mouth, the fish curling around the otter‟s head. Along the Bhimankal I walked between shrub trees of Pongamia pinnata, Parkinsonia aculeata and Salix tetrasperma and rocks on a steep slope. Well worn trails connect the waterline what looks like an “otter city”, a collection of entrances to tunnels and small caves, dripping with rainwater and with piles of fish smelling droppings. While I trespass rocky crevices, fish eagle, crested serpent eagles and brahminy kites pile up over the sky and an eagle with a fish in its claws, majestic and beautiful, landing on a dead branch high up. Few minutes later a pair of another smooth otter come into view. We can see them paddle with their hind legs, their heads on the surface and tails streaming behind them creating vortex of whirlpools. With the sound of chi chi coming out of water with their pair of heads visible with their snouts above making a linear wave of whirl of few meters. Their barking did not stop even while swirling. With every appearance above the water surface they bark and track forward for a mile together. Smooth otters are reported to dry their water drenched fur mid of every day at 1pm. They come in a strong of 16 to 17 making a ferocious gang, near ugania almost everyday, capable of frightening away even the their predators like crocodiles, hawks and eagles. Smooth otter solitary male traverses river course almost 5 km every day in search of food.
We can see caniforms rivuleting along water course with their eyes and nostrils up and whiskers flanking subsurface creating a line of wave trailing backwards. I see smooth otters sliding past perfectly disappearing in between on the water trail. Its almost impossible to chase them on a coracle boat. With a pair of good binoculars their activities could be observed with a great ease. We approached almost near them,
contrary to our anticipation, this couple stood on rocks and started staring at us with rumbling growls sound as if charging us against our unwanted advances in their territory. Meanwhile as we progressed into that direction they fade away in a moment. Suresh the fisherman of Singapore colony led us in the coracle boat along the sideline of the river amid highly bushy and shrub vegetation where we noted number of dens under the rocks and bushes. During and after the rains, the nomadic fishing tribes of Bestro, Upahar Shettys, Ganga Matasyaru and Vodru from Hassan do not restrict fishing to small ranges, and rather, are spread along the length of the river. Towards the onset of summer, as water levels decrease, large bodies of water can be expected only in areas downstream rather than upstream, and in sections where the depth is great. The south-west monsoon outbreaks in June. Once the rains begin, the water levels increase drastically. Fishes are no longer restricted to small areas and are free to extend their ranges. Accordingly, the otters will also extend their ranges in order to follow their prey. This is probably the reason why, in many of the sites, the local people had seen otters only in the rainy season. Again, during the rainy season, when the river swells, it is no longer possible for people to wade across the river, as is the practice during the dry season in many sites. This, coupled with the increased width of the river, decreases the relative disturbance along the river. The rains also make it difficult for local people to frequent the river.
Food Habits
Predation
Crocodiles are the most likely predators of smooth-coated otters which occur in abundance along the river. Other potential predators are medium jungle cats, civet cats and large birds of prey (primarily on young otters) like brahminy kite, shikra, king vultures etc18. Smooth-coated otters are supple and highly active in the water and on land use their sensitive whiskers to detect water disturbances and twitching of fishes, aquatic animals9. Associate of Weasels, Skunk and Seal family these caniform mutelids are typically social animals, with each animal in a group of 17 strong contributing to constant vigilance for feed and nourishment specially either most likely in the evening at the sun set or in the morning at the sunrise3. Pack of strong is most active mid day when they adventure for hunting the fishes and aquatic animals. Smoothcoated otters impact aquatic vertebrate and invertebrate communities via predation. Like other otters, smooth-coated otters are trapped for fur, bones, meat, whiskers, fat oil, skin pelts. Although not as luxurious as its American cousin, the river otters, the pelage of smoothcoated otters is used for garments, adornments, and other items in Tibet and China. Trained smooth-coated otters are used by fisherman to herd fish into nets. Ways that people benefit from these animals body parts specially skin pelts which are sold for Rs upto 5000 in the grey markets are yet to be studied with detailed specialization.
Mating & Courtship:
Smooth Otters are dependent on monsoons for precipitation, they are most likely to breed between August and December3. The gestation period is 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 one5. The cubs disperse at about 1 year of age. Sexual maturity is reached at Strong of 17 Smooth Otters can drive away the dreaded predator of Crocodile. Scene at Muthahi. Strong of smooth Otters creeping behind boulders waiting disappearance of driven away crocodile two years. 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 days9. 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 food5. 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 made6. 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.
Ambassador of Wetlands:
Smooth-coated otters are listed as vulnerable on the IUCN Red list13. The population is threatened by loss of wetland habitats to largescale 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. This species is considered to be Vulnerable due to an inferred future population decline due to habitat loss and exploitation8. The smooth-coated otter is essentially an otter of lowlands and floodplains. Major threats to Asian population are loss of wetland habitats due to construction of large scale hydroelectric projects, reclamation of wetlands for settlements and agriculture, reduction in prey biomass, poaching and contamination of waterways by pesticides11. In most Asian countries increased human population during the last century, inadequate and ineffective rural development programmes have not been able to address the problems of poverty, forcing people to be more and more dependent on natural resources. Consequently, most of the wetlands and waterways along the Cauvery river do not have adequate prey base for sustaining otter populations due to overexploitation of river water ecosystem. Excessive livestock grazing from Tamilnadu, commercial fishing, coracle boating, water sports diminish sustaining otter population survival. Most of the river embankments stand grappled with fish-nets especially during late in the evening which is the time for the otter to freak out for fishing, trawl and rummage for feed. Fisherman consider them as vermin and are reported to kill them for being their enemy. Most of the villages have colonized over otter cities like muthathi, biligundla, jambutapatti, attur and Singapore near bhimankal upsteam palar where smooth otter live in profuse. These are fish colonies settled over passage of time flourishing with commercial fishing business. Padyachi gowndar, bistro and madivalas are engaged in fish trade for long across the Tamilnadu side of the Cauvery river. Wetlands and waterways are polluted by eutrophication and accumulation of persistent pesticides4. Increased pesticide use is not only regarded as a major obstacle to the development of rice-fish culture, but also poses a danger to all predators feeding on aquatic prey in the area. Different chemicals such as Phoret, Thiodan, Methyl parathion, Cypermethrin, Dieldrin, Aldrin, Endrin and chemical fertilisers are increasingly used by farmers to increase crop production. These toxins run off into water bodies to be absorbed by aquatic fauna. In the entire south and southeast Asia there is severe conflict between otters and humans, because of poverty and recent increase in aquaculture activities leading to indiscriminate killing of otters. Many important habitats of smooth otter have been lost to development activities. In south east Asian countries, there does not seem to be any intentional otter trapping though it is prevalent in India, Nepal and Bangladesh. Given the extent of loss of habitat that is occurring in south and southeast Asia and the intensity of poaching the reduction in population has been observed in many parts of its range. Although quantitative data on population sizes or trends are lacking, it is suspected that the global population of otters is at stake. Its distribution is continuous from Indonesia, through Southeast Asia, and westwards from southern China to India and Pakistan, with an isolated population in Iraq. Though its current status in the Middle East is not known, its presence has been confirmed from Pakistan, India, Nepal, Bhutan, Bangladesh, Southwest China, Myanmar, Thailand, Viet Nam5. Because of secretive and nocturnal behaviour of smooth-coated otter, reliable estimates of its population are not available. In Southeast Asia it is found in large groups where the basic family group consisted of adult female and her offspring, father and older siblings often join the group. The group size of otters varies considerably between months and seasons, the group being large during the monsoon10. Along the Chambal river in Central India the group size ranges from 1-9 individuals . During a study conducted in the Corbett Tiger Reserve, in North India an estimate of 41 individuals (35 adults and 6 juveniles) was recorded from the 85 km of river stretch within the Reserve . The smooth-coated otter is essentially a plain otter. In the Indian subcontinent they are adapted to live even in the semiarid region of north-western India and Deccan plateau. Generally, it uses large rivers and lakes, peat swamp forests, mangroves and estuaries, and it even uses the rice fields for foraging. In southeast Asia rice fields appear to be one of the most suitable habitats in supporting its viable populations. However, they were more abundant in the mangroves of Kuala Gula, Malaysia as compared to the rain forest rivers. Along the large rivers in India, the smooth-coated otters prefer rocky stretches since these stretches provide sites for den and resting. River stretches with bank side vegetation and marshes are used in proportion to their availability especially in summer as they provide ample cover while travelling or foraging23. Open clayey and sandy banks are largely preferred here as they have plenty of riparian forests tree species like Euginia jambolana, Madhuca indica, Pongamia, Bombax cieba, Mangifera, Vitex negundo, Zyzyphus etc covers. Winter being the breeding season, the swamps are extensively used as natal den sites and nursery. By February-March the swamps begin to dry and the fish biomass appears to be depleted, consequently the otters move to the perennial rivers .In west Java, the smooth-coated otters prefer mangroves and tidal stretches of the rivers and rice fields. Freshwater swamps and coastal stretches lacking vegetation are avoided . In rice fields and pond areas they prefer sites having moderate diversity of vegetation. Rivers with moderate to slow or stagnant water and water bodies having a width of 10-40 m are preferred. In Huai Kha Khaeng, Thailand, the smooth-coated otters extensively use the slowly meandering river near the dam and the dam itself..
The smooth-coated otter is predominantly a fish eater, but supplements its diet with shrimp/crayfish, crab and insects, and other vertebrates such as frog, mudskippers, birds and rats. In general, its diet is similar to that of Eurasian otter. The range of fish in the diet varies from 75% to 100% .The smooth-coated otters exhibit the typical opportunistic feeding behaviour similar to the Eurasian otter. Along the major rivers in India they eat more fish, often making up to 94% of the total diet, while along the coast in mangrove habitats and in rice fields it ranges between 75-100% In west Java otters inhabiting mangrove areas eat more of crustaceans, around 22% of the scats contain remains of crab and shrimp where as in the paddy fields in Malaysia, along with fish they tend to eat more rice field rats Rattus argentiventer, represented in 23% of the spraints. Some 12 fish species identified from the spraint of smooth-coated otter from Chambal river, of which seven species were eaten throughout the year. Rhinomugil corsula (Mugilidae) and Rita rita (Bagaridae) were the preferred species. At least eight species of fish were identified from the spraints from Malaysia. Some of these include Gourami (Trichogater spp.), climbing perch (Anabis testudineus), catfish (Clarius spp.), snakehead (Channa spp.) and mudskipper (Gobioidei). Along the rice field they ate large amount of most common fish (Trichogater and Anabis spp.). The size of the fish consumed varied from 5-46 cm, often ranging between 15- 30 cm. No significant relationship was found between the calorific values of the fish and the quantities consumed. Thus, the prey selection by smooth otter is mainly influenced by its availability. Based on the percentage of active telemetry recordings, Hussain (1993) observed that the overall activity pattern of smooth-coated otters along the Chambal River in India was in the form of a bimodal curve in which two period of high activity were separated by a period of relative inactivity. This pattern of activity varied considerably among seasons10. In summer, the relative period of inactivity was greater than in winter or monsoons. A significant difference was also found between day and night time activities in different seasons11. Otters were more diurnal during winter than in summer or monsoon when they become crepuscular or nocturnal. Hussain (1993) observed daily movements of four radio-implanted smooth otters of different age and sex within their home range. Two types of movements were identified; small-scale movements associated with foraging in a restricted area close to dens, and more extensive travels between dens and foraging sites. Most of the movement was restricted between 250 to 1500 m9. A typical group of smooth-coated otter consisting of male, female, and up to four young ones require 7 to 12 km of river for their territory and an even longer stretch of shoreline if living along the coast. During a radio-tracking study along the Chambal River, India, the home range of all the otters tracked overlapped intensively. Among the radio-implanted otters, the maximum home range was observed in sub-adult male and the minimum in juvenile female and male. Among the non-tagged otters, the home range of female with cubs was estimated as 5.5 km. In case of the adult male it was estimated to be approximately 17 km. Along the Chambal River, the home range length and area of smooth coated otter was less than that of Eurasian otter, in Perthshire, Scotland and Northern river otter Lutra candensis in Idaho but larger than that of Eurasian otter in Sweden5. Increased pesticide use is not only regarded as a major obstacle to the development of rice-fish culture, but also poses a danger to all predators feeding on aquatic prey in the area. In the entire south and southeast Asia there is severe conflict between otters and humans, because of poverty and recent increase in aquaculture activities leading to indiscriminate killing of otters23. Many important habitats of smooth otter have been lost to development activities. In south east Asian countries, there does not seem to be any intentional otter trapping though it is prevalent in India, Nepal and Bangladesh. Since 1977, the smooth-coated otter is listed on Appendix II CITES. However, most range countries are not able to control the clandestine trade leading to extensive poaching. Nevertheless, it is a protected species in almost all the range countries which prohibits its killing. Otters are reported to have been hunted around dam sites in Kerala, Tamilnadu, Kudraiyar, Palar, Porundalar and Vardhaman Nadi dams near Palani including Amaravathi River. The poachers belong to Bagiri Tribe of Haryana and Vodru tribe from Hassan in Karnataka reported to have a permit that allows them to wander in the forest tracts collecting medicinal herbs and plant parts27. They claim that during the dry season, there is no source of income in their home state and they are forced to travel all the way down south in search of daily living. During the day they camp at different places as nomadic on the dam sites. Women beg alms while men hunt for otters collecting herbs, flowers and setting traps for game. Women and children also sell flowers, trinkets and bindis. Poachers of Bagiri tribe and Vodru from Hassan track otters, set traps and catch them21. Otters skin is used for making drums, the meat is eaten and the oil is extracted out of the animal fat and is used as medicine which is good cure for joint pains and pneumonia. An otter‟s presence is betrayed by its spraints and footprints. Otters are known to frequent the same spots for defecation. The traps are set on the banks of the stream close to where the tracks are visible. The traps are covered by leaves and sand. The trap is nothing but a clamp that snap shut when stepped over. Poaching appears to be the strongest threat to the otter populations along the Cauvery. Various accounts have been furnished by local people regarding poachers24. In Kodagu district, nomadic tribes, called "Wodru" by the local people, come annually to catch otters. It appears that they come from Hassan district of Karnataka. They camp for days along the riverbanks and catch as many otters as they can before they leave. The numbers culled annually is not known. Tibetans from the refugee settlements near Kushalnagar (12°25'N, 75°57'E) are known to deal in otter pelts. Lower downstream, tribes hailing from Andhra Pradesh and Gujarat. These tribes are nomadic as well and come annually, camp on the riverbanks, cull about twenty otters at a time in each location, and leave. They mostly use leghold traps. Pelts are sold and the meat is eaten. Other uses are not known locally28. The local people of Sattegala are wellknown in the neighboring villages for catching otters and dealing in pelt trade. These people have perfected the art of catching otters and offer their services to interested and prospective customers. Uncontrolled fishing along the Cauvery; in some places commercial exploitation of river water ecosystem for sale and local consumption specifically at Muthathi, Sangama, Hoganekal is cuase of depletion of the prey of otters. Fishermen also pose a threat to otters in that the animals get caught in the fishing nets left overnight and sometimes drown in the river and die of asphyxiation. The fishermen chase away otters because they tear through fishing nets and steal the catch. Dynamite fishing occurs in very few areas. Local fishermen attribute the local decrease in otter populations to this. In Galibore, Sangama and Dodmakali, where the fishes are protected and angling is a commercial sport, crackers are used to chase away the otters. The river belt forms a fodder pastureland for cattle, especially during the dry season. This attracts large populations of cattle28. There is heavy browsing and grazing along the banks of Tamilnadu side and once this resource begins to diminish, they move to islands, especially since water levels are low making it easy for the cattle to wade across. The mere presence of the cattle itself may dissuade the otters from landing. The local people also resort to burning of undergrowth in order to enhance the growth of fresh crops of fodder28. The net result is that the islands and banks are denuded of vegetation cover for the otters, making it too open for them to come on to land escaping the predators. Agriculture on the banks adds to the number of people frequenting the river. Chemical pesticides and fertilizers pollute the river6. Otters being the top carnivores of riverine ecosystems, are at a risk of accumulating these in their systems. Studies are required to identify the levels of bio accumulation of hazardous chemicals in otters5. Expansion of agricultural lands leads to encroachment into the thin green belt of trees and shrubs along the riverbanks5. Felling of trees also adds to this. This denudation of the protective vegetation deprives the otters of a crucial factor for survival. The river flows through many settlements like Bhemeshwari JLR, Muthathi, Bamsandra, Biligundla, Penagram, Hoganekal and the inhabitants utilize the water for various domestic purposes. Washing clothes, utensils and animals, and bathing are common sights. The presence of people is certainly a disturbance factor of some importance...
