- Biologically, the otter is a mustelid and is related to mink, weasels, wolverines and badgers. Mustelids are unique in having "delayed implantation," meaning that there is an inactive state during pregnancy. After several months in the inactive stage, the embryo implants in the uterine wall and development continues.
Click on the language to view common names.
Common Names in Dutch:
Common Names in English:
North American Otter, Canadian otter, North American River Otter, northern river otter, Otter, river otter
Common Names in French:
Loutre Du Canada, Loutre De Rivi, loutre de riviÃ¨re, loutre de rivière
Common Names in Spanish:
Nutria De Canad?, Nutria Norteamericana, Nutria-De R, Nutria-de rÃo norteamericana, Nutria-de río norteamericana
Species Lontra canadensis
is long and cylindrical in body shape
. It has short
and a short, thick neck. The snout is short and broad. The ears
are small, and the tail is long and thick at the base
. The feet are
The otter's dense, water-repellent fur is critical to its survival in chilly waters. Grooming the fur provides the otter with maximum levels of insulation.
Many land animals do not see well while under water, as the water distorts their vision. Otters compensate for this distortion by having strong eye muscles that change the shape of their lenses, correcting their vision while under water.
The short, dense fur is dark brown, with the face , chin, and throat having a grayish sheen.
Adults are 0.9 - 1.2 m (3 - 4 ft ) in total length and weigh 5 - 10.4 kg (11 - 23 lbs ).
The River Otter ranges widely along rivers, streams , swamps , and marshes. An individual otter may move from 77.2 - 96.6 km (48 - 60 mi ) along a waterway in a season , but the average is from 4.8 - 16.1 km (3 - 10 mi). Throughout its home range , a River Otter has "pulling out spots" where it makes "scent posts" by gathering and piling up water-logged leaves, sticks , or aquatic plants , and marking them with feces and urine. A scent post informs other otters of the River Otter's presence, but otters do not defend territories against one another.
Typically found at an altitude of 0 to 498 meters (0 to 1,634 feet).
indicate that river
were well established
throughout most major drainages
in the continental United
and Canada prior to European settlement
(Hall 1981). The continent’s
largest otter populations occurred in areas with an abundance
of aquatic habitats
such as coastal marshes, the Great
region, and glaciated areas of New England (Nilsson 1980; Toweill
and Tabor 1982; Melquist and Dronkert 1987). In addition, riverine
in interior regions supported smaller, but viable, otter
populations (Nilsson 1980).
North American river otters prefer bog lakes with banked shores containing semi-aquatic mammal burrows and lakes with beaver (Castor canadensis) lodges , and they avoid water bodies with gradually sloping shorelines of sand or gravel (Reid et al. 1994b). In Maine, use of watersheds by river otters is negatively associated with the proportion of mixed hardwood-softwood stands in forested areas adjacent to waterways and positively associated with the number of beaver flowages, watershed length, and average shoreline diversity (Dubuc et al. 1990). In Idaho, river otters prefer valley over mountain habitats, and they select valley streams over valley lakes, reservoirs , and ponds (Melquist and Hornocker 1983). Logjams are used intensively where present (Melquist and Hornocker 1983). In Florida, abundance of North American river otters is lowest in freshwater marshes, intermediate in salt marshes, and highest in swamp forest . During the dry season , L. canadensis will retreat from marshland and move to permanent ponds where water is available and food is more concentrated (Humphrey and Zinn 1982). In Idaho and Massachusetts, habitat features preferred for latrine sites include large conifers, points of land , beaver bank dens and lodges, isthmuses, mouths of permanent streams, or any object that protrudes from the water (Melquist and Hornocker 1983; Newman and Griffin 1994).The diet of the North American river otter is comprised mostly of fish that are abundant, midsized, and close to shore (Larsen 1984; Stenson et al. 1984), as well as amphibians (mostly frogs ) and crustaceans (mainly crayfish) (Knudsen and Hale 1968; Reid et al. 1994a; Sheldon and Toll 1964). Small mammals, mollusks, reptiles , birds, and fruits are consumed opportunistically (Gilbert and Nancekivell 1982; Greer 1955; Hamilton 1961; Morejohn 1969; Verbeek and Morgan 1978; Wilson 1954). North American river otters have few natural predators in the water: alligators (Alligator mississippiensis), American crocodiles (Crocodylus acutus), and killer whales (Orcinus orca). They are considerably more vulnerable on land or ice where bobcats (Lynx rufus), cougars (Felis concolor ), coyotes (Canis latrans), dogs (Canis familiaris) and wolves (Canis lupus) can kill adults (Melquist and Dronkert 1987; Melquist and Hornocker 1983; Route and Peterson 1991; Toweill and Tabor 1982). Most mortality , however, is human-related and includes trapping , illegal shooting, road kills, and accidental captures in fish nets or set lines (Jackson 1961; Melquist and Hornocker 1983).North American river otters can reach 13 years of age in the wild and up to 25 years of age in captivity (Melquist and Dronkert 1987; Stephenson 1977). Females usually do not reproduce until 2 years of age, although yearlings occasionally produce young (Docktor et al. 1987; Hamilton and Eadie 1964). Males are sexually mature at 2 years of age (Hamilton and Eadie 1964). North American river otters usually breed from December to April (Hamilton and Eadie 1964; Liers 1951), gestation lasts 61-63 days, and young are born between February and April (Hamilton and Eadie 1964; Melquist and Hornocker 1983). Litter size may reach five (Park 1971) but usually ranges from one to three (Docktor et al. 1987; Hamilton and Eadie 1964; Tabor and Wight 1977)..
List of Habitats:
- 5 Wetlands (inland)
- 5.1 Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls )
- 5.2 Wetlands (inland) - Seasonal/Intermittent/Irregular Rivers/Streams/Creeks
- 5.3 Wetlands (inland) - Shrub Dominated Wetlands
- 5.4 Wetlands (inland) - Bogs, Marshes, Swamps, Fens , Peatlands
- 5.5 Wetlands (inland) - Permanent Freshwater Lakes (over 8ha)
- 5.6 Wetlands (inland) - Seasonal/Intermittent Freshwater Lakes (over 8ha)
- 5.7 Wetlands (inland) - Permanent Freshwater Marshes/Pools (under 8ha)
- 5.8 Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)
- 5.9 Wetlands (inland) - Freshwater Springs and Oases
- 5.10 Wetlands (inland) - Tundra Wetlands (incl. pools and temporary waters from snowmelt)
- 5.11 Wetlands (inland) - Alpine Wetlands (includes temporary waters from snowmelt)
- 5.13 Wetlands (inland) - Permanent Inland Deltas
- 5.14 Wetlands (inland) - Permanent Saline, Brackish or Alkaline Lakes
- 5.15 Wetlands (inland) - Seasonal/Intermittent Saline, Brackish or Alkaline Lakes and Flats
- 5.16 Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools
- 5.17 Wetlands (inland) - Seasonal/Intermittent Saline, Brackish or Alkaline Marshes/Pools
- 9 Marine Neritic
- 9.10 Marine Neritic - Estuaries
- 12 Marine Intertidal
- 12.5 Marine Intertidal - Salt Marshes (Emergent Grasses)
- 13 Marine Coastal/Supratidal
- 13.4 Marine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes
- 13.5 Marine Coastal/Supratidal - Coastal Freshwater Lakes
- 15 Artificial/Aquatic & Marine
- 15.1 Artificial/Aquatic - Water Storage Areas (over 8ha)
- 15.2 Artificial/Aquatic - Ponds (below 8ha)
- 15.3 Artificial/Aquatic - Aquaculture Ponds
- 15.9 Artificial/Aquatic - Canals and Drainage Channels, Ditches
for foods such as rough fish
, crayfish, mollusks, crabs,
, rodents, birds, eggs
, and small reptiles
. Contrary to
, the River
does not affect the quality or quantity
of sport fish
populations. If anything, it contributes to a healthy
fish population by culling out the weak and sick individuals.
The otter preys on the fish that are the most available and the slowest. The slower fish include carp , suckers and catfish. Fish that are abundant and are found in large schools, like sunfishes and perches , are also important. The faster fishes , trout and pike , are taken less frequently by otters. Otters also eat frogs , insects, birds and small mammals.
River Otters mate in late winter and early spring . After mating, a delay of 290 - 380 days occurs before the actual development of embryos begins. Gestation takes 60 - 63 days once implantation of the embryos in the uterus occurs. In March or April, from 1 - 6 young are born in a leaf- and grass-lined den constructed in an old muskrat lodge , abandoned burrow, or hollow tree close to a water source. The young, called kits, are developed enough to leave the den with the female at 10 - 12 weeks of age. The female River Otter teaches the young to swim and hunt for food. The male may assist the female in caring for the young once they leave the den. Young remain with the female until the breeding season after their birth. A River Otter is capable of breeding once it reaches two years of age.
is an extremely intelligent animal and exhibits
high level of curiosity. When encountered along a waterway
, it will
stop and crane its neck to look at a human, if the person is moving
slowly and is not acting in a threatening manner. Otters have a playful
nature and will play both by themselves and with other otters. They
will make slides
banks into the water and use them over time
to the point
where they become deep troughs
Unlike the infamous, bad-tempered wolverine and badger, the otter loves a game. Games are most fun in a group, and here a family of otters excels. Tag , hide-and-seek, keep-away and wrestling may start the day. A muddy riverbank becomes a free-for-all slide that improves with use. Zoom, kerplunk! Then up to the top of the slope for another turn . After a day of sliding, tail chasing, stick juggling, and a few rolls in the grass or snow, it's into a den for a huddled snooze. Play behavior indicates intelligence, and the otter doesn't come up short.
The River Otter is most active from dawn to midmorning and again in the evening.
The River Otter has few natural predators , but there are reports of it being preyed upon by American Alligators, Bobcats, and Coyotes. River Otters have lived for 20 years in captivity, but 5 - 7 years is the average in the wild.
- Whittaker & Margulis,1978
- C. Linnaeus, 1758
- (Hatschek, 1888) Cavalier-Smith, 1983
- Grobben, 1908
- (Haeckel, 1874) Cavalier-Smith, 1998
- Bateson, 1885
- Cuvier, 1812
- Jawed Vertebrates
- Goodrich, 1930
- C. Linnaeus, 1758
- (Rowe, 1988) M.C. McKenna & S.K. Bell, 1997
- (Wible et al., 1995) M.C. McKenna & S.K. Bell, 1997
- McKenna, 1975
- McKenna, 1975
- McKenna, 1975
- (McKenna, 1975) M.C. McKenna & S.K. Bell, 1997
- (Parker & Haswell, 1897) M.C. McKenna & S.K. Bell, 1997
- (Owen, 1837) M.C. McKenna & S.K. Bell, 1997
- (Mckenna, 1975) M.c. Mckenna & S.k. Bell, 1997
- (McKenna, 1975) McKenna, in Stucky & McKenna, in Benton, ed., 1993
- (Linnaeus, 1758) McKenna, 1975
- Bowdich, 1821
- Kretzoi, 1943
- Infraorder: Arctoidea () - Flower, 1869
- Suborder: Caniformia () - Kretzoi, 1943
- Order: Carnivora () - Bowdich, 1821
- Grandorder: Ferae () - (Linnaeus, 1758) McKenna, 1975
- Superorder: Preptotheria () - (McKenna, 1975) McKenna, in Stucky & McKenna, in Benton, ed., 1993
- Magnorder: Epitheria () - (Mckenna, 1975) M.c. Mckenna & S.k. Bell, 1997
- Cohort: Placentalia () - (Owen, 1837) M.C. McKenna & S.K. Bell, 1997
- Supercohort: Theria () - (Parker & Haswell, 1897) M.C. McKenna & S.K. Bell, 1997
- Infralegion: Tribosphenida () - (McKenna, 1975) M.C. McKenna & S.K. Bell, 1997
- Sublegion: Zatheria () - McKenna, 1975
- Legion: Cladotheria () - McKenna, 1975
- Superlegion: Trechnotheria () - McKenna, 1975
- Infraclass: Holotheria () - (Wible et al., 1995) M.C. McKenna & S.K. Bell, 1997
- Subclass: Theriiformes () - (Rowe, 1988) M.C. McKenna & S.K. Bell, 1997
- Class: Mammalia () - C. Linnaeus, 1758
- Superclass: Tetrapoda () - Goodrich, 1930
- Infraphylum: Gnathostomata () - auct. - Jawed Vertebrates
- Subphylum: Vertebrata () - Cuvier, 1812 - Vertebrates
- Phylum: Chordata () - Bateson, 1885 - Chordates
- Infrakingdom: Chordonia () - (Haeckel, 1874) Cavalier-Smith, 1998
- Branch: Deuterostomia () - Grobben, 1908
- Subkingdom: Bilateria () - (Hatschek, 1888) Cavalier-Smith, 1983
- Kingdom: Animalia () - C. Linnaeus, 1758 - animals
Status: Accepted Name
Last scrutiny: 15-Aug-2007
River otters from North and South America were recognized as distinct from their European river otters by van Zyll de Jong (1987). However, the genus name Lontra is rarely used in the present literature, and numerous authors still use Lutra (Kellnhauser 1983). Herein, Lontra is used in concordance with van Zyll de Jong (1972, 1987) and Wozencraft (2005)..
No other large aquatic mammal in North America looks like a River Otter. Both the Beaver and the Muskrat are stocky and squat in build, whereas the River Otter is long and slender.
Members of the genus Lontra
ZipcodeZoo has pages for 8 species and subspecies in this genus:
L. canadensis (North American Otter) · L. canadensis canadensis (North American River Otter) · L. canadensis kodiacensis (Kodiak River Otter) · L. canadensis mira (Northern River Otter) · L. canadensis sonora (Southwestern Otter) · L. felina (Marine Otter) · L. longicaudis (South American River Otter) · L. provocax (Southern River Otter)
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- A systematic review of the Nearctic and Neotropical River otters (genus Lutra, Mustelidae Carnivora) / Toronto: Royal Ontario Museum, 1972. url p. 68, p. 81, p. 83, p. 84, p. 85, p. 86, p. 97, p. 99.
- Bulletin of the Museum of Comparative Zoology at Harvard College. 157 2001 Cambridge, Mass.: The Museum, 1863- url p. 175.
- Checklist of CITES Species CITES, WCMC url p. 174, p. 189.
- Checklist of CITES Species: a reference to the appendices to the Convention on International Trade in Endangered Species of Wild Fauna and Flora CITES url p. 159, p. 162, p. 177, p. 178, p. 187, p. 199.
- Checklist of mammals listed in the CITES appendices and in EC Regulation 338/97 JNCC url p. 67.
- Illinois River Bluffs area assessment / Illinois Department of Natural Resources, Office of Scientific Research and Analysis, [and the] State Geological Survey Division. Springfield, Ill.: Illinois Dept. of Natural Resources, 1998- url p. 25, p. 99.
- Mammals of the Soviet Union / V.G. Heptner, A.A. Nasimovich, and A.G. Bannikov; scientific editor, Robert S. Hoffmann. Washington, D.C.: Smithsonian Institution Libraries and National Science Foundation, 1988- url p. 1286.
- Occasional papers of the Museum of Natural History, the University of Kansas. Lawrence, Kan.: The University, 1971-1994. url , p. 34.
- Publications in zoology = Publications en zoologie. Ottawa: National Museums of Canada, National Museum of Natural Sciences, 1970-1982. url p. 12, p. 125, p. 152, p. 31, p. 32, p. 37.
- Reports on zoology for 1843, 1844 / Tr. from the German by George Busk, Alfred Tulk, esq., and Alexander H. Haliday, esq. London: Printed for the Ray society, 1847. url p. 29, p. 581.
- The Canadian field-naturalist. Ottawa, Ottawa Field-Naturalists' Club. url p. 120, p. 126, p. 194, p. 325, p. 326, p. 35, p. 380, p. 388, p. 459, p. 460, p. 467, p. 470, p. 483, p. 503, p. 509, p. 516, p. 518, p. 532, p. 583, p. 585, p. 633, p. 636, p. 663, p. 695, p. 744, p. 96.
- Transactions of the Kentucky Academy of Science. [Lexington, Ky.]Kentucky Academy of Science, 1923-1997. url p. 83.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 13, 2012.
- IUCN 2012. IUCN Red List of Threatened Species. Version 2011.2. . Downloaded on January 28, 2012.
- Sefass, T. & Polechla, P. 2008. Lontra canadensis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloadedon 01February2012.
Accessed through GBIF Data Portal February 29, 2008:
- Borror Laboratory of Bioacoustics
- Burke Museum: Mammal Specimens
- Cornell University Museum of Vertebrates: Mammal Collection
- Field Museum: Mammal specimens
- GBIF-Sweden: Mammals (NRM)
- Institute of Marine and Coastal Sciences, Rutgers University: Bay of Fundy Species List (OBIS Canada)
- Louisiana State University Museum of Natural Science: Mammal specimens
- Marine Science Institute, UCSB: Paleobiology Database
- Michigan State University Museum: Vertebrate specimens
- Museum of Texas Tech University (TTU): Mammal specimens
- Royal Ontario Museum: Mammal specimens
- Santa Barbara Museum of Natural History: Santa Barbara Musem of Natural History
- Sternberg Museum of Natural History: Mammal Collection
- University of Alaska Museum of the North: University of Alaska Museum Mammal Collection
- University of Alaska Museum of the North: University of New Mexico Museum of Southwestern Biology Mammal Collection
- University of Kansas Biodiversity Research Center: Mammal Collection
- University of Minnesota Bell Museum of Natural History: Mammal specimens
- Biodiversity Heritage Library NamebankID: 105593
- Catalogue of Life Accepted Name Code: ITS-727009
- Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 180549
- IUCN ID: 220353
- Natural Heritage Network Species Identifier: AMAJF10010
- Zipcode Zoo Species Identifier: 125
- New Mexico Wildlife. New Mexico Department of Game and Fish Version of April 24, 2009. [back]
- Mean = 74.720 meters (245.144 feet), Standard Deviation = 84.250 based on 85 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
- Sefass, T. & Polechla, P. 2008. Lontra canadensis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 01 February 2012. ... [back]