The southern river otter is a rare amphibious mammal that inhabits a limited number of rivers, lakes, canals and calm, heavily vegetated coastal areas of Chile and Argentina in Patagonia, South America. While similar in appearance to other New World (Lontra) otters, it is the smallest otter in its genus. It is sometimes referred to as the Chilean Otter, and locally as the Huillín.
This semi-aquatic mammal is a member of the Mustelidae family, which includes badgers, weasels, mink and otters. Its range once extended throughout much of Chile, but it is now limited to several Chilean provinces and parts of southern Argentina, from southern Neuquen Province to Tierra del Fuego. This range is the smallest geographical range of any otter species.
The preferred habitat of the Southern river otter is rivers, streams, lakes, canals, estuaries, swamps, and calm coastal bays, fjords or wetlands with abundant vegetation. Researchers believe that the presence of dense, mature vegetation close to the water's edge, especially with many fallen trees, is among the key factors necessary for healthy populations of this species.
Southern river otters resemble other New World (Lontra) otters, as they have long, slender bodies with short legs and a long, thick tail that tapers to a point. Their feet have sharp claws and are webbed for swimming. They are the smallest of the Lontra otters, as they weigh between 4.5 kg (10 lbs) and 9 kg (20 lbs). They measure roughly 91 cm (36 inches) including the tail.
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| Picture of southern river otter, Chilean otter or South American river otter, Lontra provocax, endangered species |
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Kingdom:
Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia/Canoidea
Family: Mustelidae/Mustelids
Genus: Lontra
Specific: provocax
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The Southern river otter's fur is generally dark brown, with a light colored underbody and throat. Like other otters, they have very dense fur made up of a fine undercoat protected by thicker guard hairs. Their fur traps air, keeping the animal warm in water. Their nose is shaped somewhat like a pentagon, which helps to identify them in the field.
Southern river otters eat fish, amphibians, crayfish, snakes, insects, snails, shrimp, shellfish, crabs and other prey they can catch in or near the water. The Argentine populations are said to be more dependent on crustaceans as a food source than the Chilean populations.
A study by Claudio Chehebar, et al, described the dietary habits of one specific population of Southern river otters at Nahuel Huapi Lake on the Quetribue Peninsula of Argentina. According to analysis of otter spraint (droppings) there, Aegla anomura, a species of freshwater crab endemic to South America, and Sammastacus spinifrons, a crayfish, make up the majority of its diet, with fish making up only 10%.
Southern river otters are typically solitary and do not generally travel in groups, with the exception of a mother and pups. They are primarily nocturnal. They are said to have a very short lifespan in the wild, with only 1% surviving to the age of 10 years.
The IUCN lists Southern river otters as Endangered. The greatest threat to the species is habitat destruction, followed by poaching, especially in areas where they are perceived to be a threat to fish and crab farming. Already rare, this species is expected to experience a further 50% reduction in numbers in the coming years.
Currently a question of interest among researchers is the effect of competition on southern river otters by the introduced species, the American mink, Mustela vison. Mink are believed to negatively impact otter populations, as they compete for food on the river banks and are voracious feeders. They are also known to take over otter dens.
There are some organizations and individuals devoted to improving conditions for survival of the Southern river otter as a species. Notable among organizations are:
Project Huillín, CODEFF (Spanish)
http://www.webcodeff.cl/espanol/sitio/rev.asp?Id=226&Num=22&Ob=1&Rev=1
http://www.conama.cl/portal/1301/article-32041.html
Darwin Initiative
http://www.profauna.org.ar/DI%20introduction.htm
Grupo de Estudios en Ecologia Mamiferos (GEMA) (Spanish)
http://www.gema.unlu.edu.ar/
Names of individuals associated with Southern river otter conservation and research include:
Jose Luis Bartheld, Maximiliano Sepúlveda, Gonzalo Medina-Vogel, Claudio Chéhebar, M.B. Aued, Adriana Gallur, Maria Gottelli, Guillermo Giannico, Pablo Yorio, Patricia Livingston, Javier Perez Calvo, Graciela Artigas, Alcides Iacopini, Rosa Flores, D. W. Macdonald, M. H. Cassini, Vera Kaufman, Rene Monsalve, Vincente Gomez, G. Porro, Dr. Adrián Schiavini, Laura Malmierca, Cecilia Gozzi, Laura Fasola, Martha Saithe
Alternate Lontra Provocax names: South American River Otter, Chilean River Otter, Huillín, Huillin, Patagonian River Otter, Loutre du Chili, Lobito Patagonico, Nutria Chilena, Nutria de Chile
© Southern river otter information assembled from on-line sources by Kevin
Miller on July 28, 2008 for Seapics.com.
http://animaldiversity.ummz.umich.edu/site/accounts/information/Lontra_provocax.html
http://www.lioncrusher.com/animal.asp?animal=178
http://www.otterspecialistgroup.org/Species/Lontra_provocax.html
http://jhered.oxfordjournals.org/cgi/content/abstract/99/2/198
http://www.iucnredlist.org/search/details.php/12305/all
http://www.bariloche.org/aldia/articulos/Naturaleza/huillin_2005.shtml
http://www.ambiente-ecologico.com/ediciones/2002/084_05.2002/084_Fauna_Chiappe_Chehebar.php3
http://www.conama.cl/portal/1301/article-32041.html
http://www.webcodeff.cl/espanol/sitio/rev.asp?Id=226&Num=22&Ob=1&Rev=1
http://darwin.defra.gov.uk/documents/13016/4566/13-016%20AR2%20-%20edited.pdf
http://www.gema.unlu.edu.ar/publicaciones.htm |