Southern River Otter subpopulations that inhabit marine environments are distributed along the Pacific coast of Chile from 46S to Tierra del Fuego in Chile (Cabrera 1957, Redford and Eisenberg 1992, Sielfeld 1992, Malmierca et al. 2006). In Argentina, marine subpopulations are present only in the Archipielago Fueguino in Los Estados Island and the Beagle Channel (Malmierca et al. 2006, Valenzuela et al. 2012, Valenzuela et al. 2013). Marine river otters in Argentina are probably a continuous subpopulation of the main otter subpopulation in Chile (Sielfeld 1992).
Southern river otters, Lontra provocax, are only found in central and southern Chile and parts of Argentina. This species has been exterminated from much of its range in Chile by hunting. In Argentina, it is found along the Andes from Tierra del Fuego all the way to the southern part of Neuquen province (Otternet, 1998).
Biogeographic Regions: neotropical (Native )
L. provocax is a medium sized otter. It ranges from 1000 mm to 1160 mm in total length. Its tail is 350 to 460 mm long. These otters possess webbed feet with strong claws. Their hair has a velvety texture. The guard hairs range in length from 15 to 17 mm, and the under fur is 7 to 8 mm long. The dorsum is a very dark brown, which strongly contrasts with the silvery whitish ventrum. Their nose is diamond-shape with the bottom corner squared off (Otternet, 1998).
Range length: 1000 to 1160 mm.
Other Physical Features: endothermic ; bilateral symmetry
Habitat and Ecology
The Southern River Otter is distributed in the southern temperate forest of South America. This species presents a distribution associated with inland waters in the northern parts of its range, and marine habitat in the southern part of its range. In freshwater habitats otters are associated with the presence of macro-crustaceans from the genus Aegla spp. and Sammastacus spp. (Aued et al.2003,Cassini et al. 2009,Seplveda et al. 2009), which are the otters main prey (Medina 1997,Medina-Vogel and Gonzalez-Lagos 2008,Fasola et al. 2009,Rodrguez-Jorquera and Seplveda 2011,Franco et al. 2013). Other species of crustaceans, fish and amphibians are also in the otters diet but are of marginal occurrence. The otter use rivers with abundant vegetation (Chehebar et al. 1986,Medina-Vogel et al. 2003) and inhabit diverse types of wetlands including Andean lakes, rivers of different sizes, ponds and estuaries. A study using telemetry described an average home range of 11.3 km, with solitary behaviour and a low spatial overlap between individuals of same sex suggesting intrasexual territoriality (Seplveda et al. 2007). In the marine range the species uses the marine rocky coast with abundant vegetation cover and low exposure to wind and waves (Sielfeld 1992,Sielfeld and Castilla 1999). In this environment the Southern River Otter is sympatric with the Marine Otter (L. felina), but the later is segregated by its use of more wave-exposed coastal areas (Sielfeld 1992,Ebensperger and Botto-Mahan 1997). The diet in the marine environment is composed of coastal fish of the genera Harpagifer, Patagonotothen, Eleginops, Cottoperca and crustaceans of the genera Munida, Taliepus, Cancridae, Galatheidae, Lithodidae, Lithodes, Paralomis and Campylonotus(Sielfeld and Castilla 1999,Valenzuela et al. 2013). In general for both marine and inland waters the Southern River Otter seems to be a specialized aquatic bottom forager preying on slow benthic fish and crustaceans.
L. provocax inhabits both marine and fresh waters. It is found on rocky coasts and in protected canals in areas where there are few waves. It does not live in open coastal areas, but instead prefers coastal and freshwater environments with dense vegetation (Redford and Eisenberg, 1992).
Habitat Regions: terrestrial ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; coastal
Other Habitat Features: estuarine
L. provocax diet varies within the separate habitat types. In a Chilean population, 75% of fecal samples analyzed had fish in them, and 63% had crustaceans. In Argentina the feces showed 99% of scats had crustaceans and only 2% contained fish (Medina, 1998). In addition to fish and crustaceans, southern river otters also eat mollusks and birds (Kruuk, 1995).
Animal Foods: birds; fish; terrestrial non-insect arthropods; mollusks
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods)
This species probably acts as an important control on mollusk, fish, and crustacean populations.
Humans are known predators (Redford and Eisenberg, 1992). There are no reports of non-human predation on this species.
- humans (Homo sapiens)
This list may not be complete but is based on published studies.
Known prey organisms
This list may not be complete but is based on published studies.
Life History and Behavior
Perception Channels: tactile ; chemical
A high proportion of the individuals die before they reach maturity. Only about 1% will survive to reach 10 years of age. Most L. provocax only live a few years (Chanin, 1985).
Status: wild: 10 (high) years.
Status: wild: 3 (low) years.
Status: wild: >3 years.
The mating system of this species has not been reported.
River otters typically breed in the winter and spring, with births taking place the following year. Because there is a delay between mating and implantation of the fertilized eggs, there can be a great variability in the length of pregnancy. Although gestation has been reported to be 10-12 months long, actual embryonic development is around two months (Nowak, 1999).
Females have four nipples and produce one to four young each season, but usually produce only one or two young. L. provocax young are born a helpless, blind and scarcely mobile. Young spend their time in the den either suckling or sleeping. The milk is an extremely rich energy source and the young have a high metabolic rate. They open their eyes at approximately one month and begin to eat solid foods at 7 weeks. They begin to swim at about 3 months of age. They are usually capable of catching their own food within 4 months. The young remain with the family group for the first year before they disperse (Chanin, 1985). Reproductive maturity is attained in the second or third year of life.
Breeding season: Breeding occurs in the winter and spring, with births occuring the following year.
Range number of offspring: 1 to 4.
Average number of offspring: 1-2.
Range gestation period: 10 to 12 months.
Range age at sexual or reproductive maturity (female): 2 to 3 minutes.
Range age at sexual or reproductive maturity (male): 2 to 3 minutes.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous ; delayed implantation
As in all mammals, the female provides milk for her offspring. Young are altricial and are cared for by the mother until they disperse. Other aspects of parental care in this species are not known.
Parental Investment: altricial ; female parental care
IUCN Red List Assessment
Red List Category
Red List Criteria
This species is considered to be Endangered under criterion A3cde due to projected future population decline due to habitat loss. Accelerating habitat destruction and degradation throughout the Southern River Otter's range is the greatest threat to the species, and is projected (based on current trends) to lead to a future >50% reduction in population size over the next 30 years (three generations based on Pacifici et al. 2013) for those subpopulations using rivers and lakes (freshwater habitats). For the subpopulations using the southern fjords and islands (marine habitats) of Chile the population may reduce to 50% over the next 30 years due to the impacts of intensive fishery activities. The distribution of the Southern River Otter has declined drastically due to combined pressures from the destruction of habitat, removal of vegetation, river and stream canalization, and extensive dredging (Medina 1996,Medina-Vogel et al.2003). At present, poaching is a minor problem but still occurs particularly south of 43S latitude where control of hunting is difficult to implement. Extirpation of the Southern River Otter began in local basins but has become widespread. The lack of re-establishment of the species is probably due to high mortality or reproductive failure following the dispersal of otters into unsuitable areas (Medina 1996). This is resulting in a population that is becoming increasingly fragmented and more susceptible to local extinctions through habitat destruction, human disturbance, predation by domestic dogs, and demographic or environmental stochastic events. Genetic studies have confirmed a lower genetic diversity in the northern freshwater subpopulations in comparison to those from the south confirming a past bottleneck probably due to anthropogenic factors (Centron et al. 2008,Vianna et al. 2011).
- 2008Endangered (EN)
- 2004Endangered (EN)
- 2000Endangered (EN)
- 1996Vulnerable (VU)
- 1996Vulnerable (VU)
- 1994Vulnerable (V)
- 1990Vulnerable (V)
- 1988Vulnerable (V)
- 1986Indeterminate (I)
- 1982Indeterminate (I)
Lontra provocax is listed as an endangered species. This is primarily due to illegal hunting, habitat loss and water pollution (Redford and Eisenberg, 1992).
CITES: appendix i
IUCN Red List of Threatened Species: endangered
Date Listed: 06/14/1976
Lead Region: Foreign (Region 10)
Where Listed: Chile,Argentina
Population location: Chile,Argentina
Listing status: E
For most current information and documents related to the conservation status and management of Lontra provocax, see its USFWS Species Profile
Freshwater subpopulations have been described as fragmented and comprised of seven isolated subpopulations (Medina 1996) but subsequent surveys have identified presence in areas previously thought not to have otters (Rodrguez et al. 2008); it is not clear if this is the result of a recent recolonization or sampling bias in earlier studies, and more research is needed. A radiotelemetry study in the Queule River found densities of 0.25 otters/km of river (Seplveda et al. 2007).
Studies of the marine population in Chile indicate that the otter distribution in this environment would be continuous and abundances estimated are 0.57 otters/km of coast (Sielfeld 1992). Studies based on indirect signs in marine populations in Argentina, indicate two separate subpopulations, one in Isla de Los Estados (Provincial Reserve) and the other in Bahia Lapataia, Tierra del Fuego National Park, in the Beagle Channel (Valenzuela et al. 2012).
During 1910-1954 a total of 38,263 otter pelts (Lontra felina and L. provocax) were exported from Chile but after that period no exports exist due to the implementation of different laws and international agreements (Iriarte and Jaksic 1986) .
In Chile, the conservation status is listed by the Reglamento de Clasificacin de Especies as Endangered in VI, VII, VIII, IX, XIV and X Districts and as Data Deficient in XI and XII Districts (Chile 2011). In Chile, the Subsecretaria de Pesca is the governmental agency responsible of their conservation and management. In those populations inside official protected areas the Corporacion Nacional Forestal is responsible of their conservation. National Action plans in Chile are developed by the Minisiterio del MedioAmbiente, but despite its conservation status no Action Plan exists for this species at present, which is the most urgent conservation action priority. Hunting is prohibited since 1929 in Chile (Iriarte and Jaksic 1986) and the governmental agency responsible for hunting permits and enforcement is the Servicio Agricola y Ganadero.
In Argentina the conservation status is Endangered (EN A3cd) (Valenzuela et al. 2012). At national level, the governmental agency responsible of native wildlife conservation and management is the Secretara de Ambiente y DesarrolloSustentable de la Nacin through the Direccin de Fauna Silvestre. The Administracin de Parques Nacionales (National Parks Administration) is responsible of conservation of those populations inside the national protected areas, where the species is classified as Special Value Species (APN 1994.). The two populations in Argentina from freshwater and marine habitats are mostly inside national protected areas.
Because of the several agencies involved in the management of the species a strong coordination with clear responsibilities and a work agenda is a major urgency in the short term. Actions recommended for both Chile and Argentina are:
- To develop a Conservation Bi-National Plan for the species;
- To develop specific National Conservation Plans for each country;
- To develop validated Monitoring Programmes in protected and unprotected lands;particularly in Chile where there is no such activity in any population; and
- To reinforce the importance of environmental impact assessment projects in relation to the species in order to adequately determine: a) presence of otter population in areas of projects, and b) in those projects requiring to implement adequate actions to incorporate: 1) measures of monitoring, 2) mitigation and 3) compensation activities.
There have not been any reintroduction attempts, which could be an appropriate conservation action considering the success of such plans in North American and European species. Although otters are one of the most appealing species in zoo/aquarium exhibitions providing good opportunities for education and awareness about conservation issues in aquatic environments, no known individuals of the Southern River Otter are currently in captivity and there are no historical records for any captive animals.
Relevance to Humans and Ecosystems
No negastive effects of this species on human populations has been noted.
L. provocax was harvested for its fur, but it is now illegal to harvest these animals. However, poachers are still a threat to this species (Redford and Eisenberg 1992).
Southern river otter
The southern river otter, Lontra provocax, is a species of otter that lives in Chile and Argentina. Although called a "river otter", it inhabits both marine and freshwater environments. It sometimes is considered a subspecies of Lontra canadensis. The southern river otter is listed as endangered, due to illegal hunting, water pollution, and habitat loss.
This medium-sized otter's body can grow up to 2.5 ft (70 cm) long, with a tail adding about 16 in (40 cm). Body weight averages about 5-10 kg (11-22 lbs). Its fur is dark-brown on the top and has a lighter cinnamon color on its underside.
Although the female and her young will live in family groups, males are usually solitary. Litter sizes average one to two pups, but up to four can be born at a time. Their diets include fish, crustaceans, mollusks, and birds.
The southern river otter can be found in marine, freshwater, and terrestrial habitats, but are mostly found in freshwater lakes and rivers having a significant amount of dense vegetation, especially along the shorelines, which must be present to use as cover. Their habitats also need the root systems of mature trees, as well as fallen tree debris.
Southern river otters were vigorously hunted for their pelts throughout the last 100 years. This is the major cause of their current low population numbers and endangered conservation status. Since then, they have not been able to recover due to a number of other threats. At this point, only seven known populations of this species are found throughout Chile and Argentina, and all of the populations are isolated from each other.
The riparian forests and rivers in which these otters are mostly found have been disturbed by human presence. Dam and road construction, as well as stream canalization and drainage for agriculture destroy many acres of what could be habitat for this species. Though Argentina began passing legislation in 1960 to outlaw the hunting of the southern river otter, hunting still does occur because of the lack of enforcement. Hunting is legal and does occur in Chile.
The continual decrease in prey numbers also causes problems for the southern river otter. Some invasive aquatic species that have been introduced into that area are limiting the mollusks and fish available for otter prey. This causes the otters to move to other freshwater systems to hunt for food.
Several surveys and studies have been performed on the southern river otter to better understand its declining population numbers to be able to prevent the species from becoming extinct. Several of the known populations are found within national forests.
One survey in particular was performed to determine if any of this species live within these protected areas. The author surveyed three parks in Argentina: Lanin, Puelo, and Los Alerces National Parks. The surveyors spoke with people who live and work near these areas, and looked for prints and droppings of the southern river otter, while also looking for signs of the American mink. The mink was introduced into this area and is thought to compete with the southern river otter for food resources and habitat space. The results showed signs of the southern river otter were found in 32 of the 275 surveyed sites within the three parks. Of the 32 confirmed sites, 31 were of dense forest with thick undergrowth near the shorelines of freshwater systems. These results suggest having shoreline vegetation for cover is vital for their survival.
Future directions for conserving this species include obtaining better information on the southern river otter’s population numbers and locations. If conservationists know where the individuals and families live, enforcement of antipoaching laws, as well as focusing on maintaining and protecting their habitats, will be easier. Captive breeding programs would also be beneficial for this species, to later reintroduce individuals into the areas where they were previously found.
- M. Sepulveda, M. Franco, G. Medina, L. Fasola & R. Alvarez (2008). "Lontra provocax". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Retrieved 10 May 2012.
- Marcelo H. Cassini, Laura Fasola, Claudio Chehébar & David W. Macdonald (2010). "Defining conservation status using limited information: the case of Patagonian otters Lontra provocax in Argentina". Hydrobiologia 652 (1): 389–394. doi:10.1007/s10750-010-0332-6.
- M. A. Sepúlveda, J. L. Bartheld, C. Meynard, M. Benavides, C. Astorga, D. Parra & G. Medina-Vogel (2009). "Landscape features and crustacean prey as predictors of the southern river otter distribution in Chile". Animal Conservation 12 (6): 522–530. doi:10.1111/j.1469-1795.2009.00304.x.
- Claudio E. Chehébar, Adriana Gallur, Guillermo Giannico, María D. Gottelli & Pablo Yorio (1986). "A survey of the southern river otter Lutra provocax in Lanin, Puelo and Los Alerces national parks, Argentina, and evaluation of its conservation status". Biological Conservation 38 (4): 293–304. doi:10.1016/0006-3207(86)90056-X.
- L. Fasola, C. Chehébar, D. W. Macdonald, G. Porro & M. H. Cassini (2009). "Do alien North American mink compete for resources with native South American river otter in Argentinean Patagonia?". Journal of Zoology 277 (3): 187–195. doi:10.1111/j.1469-7998.2008.00507.x.
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