Animal Diversity Web

Ge­o­graphic Range

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

Habi­tat

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

Phys­i­cal De­scrip­tion

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).

• Other Physical Features
• endothermic
• bilateral symmetry

• Range length

  1000 to 1160 mm

  39.37 to 45.67 in

De­vel­op­ment

See Re­pro­duc­tion.

Re­pro­duc­tion

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.

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

• 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

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

Lifes­pan/Longevity

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).

• Range lifespan
  Status: wild

  10 (high) years

• Typical lifespan
  Status: wild

  3 (low) years

• Average lifespan
  Status: wild

  >3 years

Be­hav­ior

L. provo­cax tends to be found in fam­ily groups that con­sist of the adult fe­male and her young. Males are usu­ally soli­tary ex­cept dur­ing the mat­ing sea­son. Males also tend to have a larger home range than fam­ily groups. Both sexes of this species are usu­ally ac­tive dur­ing the night (Chanin, 1985).

• Key Behaviors
• nocturnal
• motile
• solitary
• social

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• tactile
• chemical

Food Habits

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).

• Primary Diet
• carnivore
  • piscivore
  • eats non-insect arthropods

• Animal Foods
• birds
• fish
• terrestrial non-insect arthropods
• mollusks

Pre­da­tion

Hu­mans are known preda­tors (Red­ford and Eisen­berg, 1992). There are no re­ports of non-hu­man pre­da­tion on this species.

• Known Predators

  • humans (Homo sapiens)

Ecosys­tem Roles

This species prob­a­bly acts as an im­por­tant con­trol on mol­lusk, fish, and crus­tacean pop­u­la­tions.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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).

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

No ne­gas­tive ef­fects of this species on human pop­u­la­tions has been noted.

Con­ser­va­tion Sta­tus

Lon­tra provo­cax is listed as an en­dan­gered species. This is pri­mar­ily due to il­le­gal hunt­ing, habi­tat loss and water pol­lu­tion (Red­ford and Eisen­berg, 1992).

• IUCN Red List

  Endangered
  More information

• IUCN Red List

  Endangered
  More information

• CITES

  Appendix I

Con­trib­u­tors

William Haase (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: Facts on File.

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

Med­ina, G. Sept., 1998. Sea­sonal vari­a­tions and changes in the diet of south­ern river otter in dif­fer­ent fresh­wa­ter habi­tats in Chile. Acta-The­ri­o­log­ica, 43 (3): 285-292.

Ot­ter­net, 1998. "Species Pro­file: South­ern River Otter" (On-line). Ac­cessed Oc­to­ber 28, 2001 at http://​www.​otternet.​com/​species/​srotter.​htm.

Red­ford, K., J. Eisen­berg. 1992. Mam­mals of the Neotrop­ics: The South­ern Cone Vol. 2. Chicago, IL: Uni­ver­sity of Chicago Press.