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Species Description

• Adult total length: 37 - 49 in. (950 - 1,250 mm)

• Tail: 12 - 19 in. (300 - 475 mm)

• Hind foot: 4 1/4 - 5 1/4 in. (110 - 135 mm)

• Weight: 10 - 25 lbs. (4.5 - 11.5 kg)

• Physical Characteristics: The northern river otter is a slender, long-bodied, short-legged mammal with a broad, flat head and a muscular body. The snout is broad and rounded, the ears are small, and the feet are webbed. The stout, tapering tail serves as a rudder when swimming. The brownish fur is short and dense. The skin and throat are grayish-white. The prominent facial whiskers are extremely sensitive to touch.

left lateral view of skull and mandible	dorsal view of skull	ventral view of skull

• Range Maps

  North America	Great Smokies

• Great Smoky Mountains National Park: River otters were reported to be common in the rivers of eastern Tennessee, including the Tellico River, by Lt. Henry Timberlake in 1762 (Williams, 1927). Buckley (1859) reported that otter skins were among those bought by traveling fur merchants in the Smokies. As late as 1896, Rhoads considered the river otter to be "a rare but constant inhabitant of all the larger streams in the State [Tennessee]." By the 1930s however, when the park was created, uncontrolled trapping had nearly eliminated the otter. A group of three otters was observed in Cataloochee in 1927. An otter was trapped on Cataloochee Creek in 1930, a pair was seen near Mount Sterling in 1931, and one was seen several different times at the same location near Elkmont in 1934. The last reliable sighting of a native otter was an individual seen in Cataloochee Creek in 1936 (see Stupka or King, journals).

  The National Park Service began a reintroduction program in 1986. Between February 26 and March 31, 11 river otters were obtained from North Carolina and released on Abrams Creek ( Griess, 1987). Beginning in December, 1988, 14 additional otters from South Carolina and Louisiana were released in Little River (Miller, 1992). Six otters were released in 1992 in Cataloochee Creek, four in Hazel Creek, and two in the Little River (DeLozier, pers. comm., December 1993). Most of the reintroduced otters established home ranges within the park, although one is known to have established a home range in the French Broad River outside the Park (Linzey, 1995a ). Three of the otters released in the Little River crossed the mountains and established their home ranges on the North Carolina side of the Park. During January, 1994, the National Park Sevice released 100 additional river otters from Louisiana into the following park streams: West Prong and Middle Prong of the Little Pigeon River, Big Creek, Cataloochee Creek, Abrams Creek, Little River, Twentymile Creek, Tab Cat Creek, Oconaluftee River, Deep Creek, Eagle Creek, Forney Creek, Pilkey Creek, Chambers Creek, and Noland Creek. These releases concluded the otter reintroduction program.

  • Blount Co.: Abrams Creek; Gregory Bald.

  • Sevier Co.: Sugarlands; Greenbrier; Little River.

  • Haywood Co.: Big Creek; Cataloochee; Mt. Sterling.

  • Swain Co.: Bear Creek above Bryson Place; Hazel Creek.

Index

Natural History

• Reproduction
  Litters are usually born in March or April. Delayed implantation of the embryos causes a gestation of 288 to 380 days. The fertilized egg starts its development as it travels down the oviduct. Reaching the uterus in the blastocyst stage, it then becomes inactive, the metabolic rate falls, and cell division ceases. The unimplanted blastocyst remains quiescent for a period of ten to eleven months before implantation and normal development resumes. Usually two or three young are born in a nest of dry vegetation within the den. Newborn otters are blind, toothless, and covered with brownish-black fur that fades ventrally to a lighter, more grayish tone. The pups are cared for by the female until approximately six months of age, after which both parents assist in their care and protection. The pups leave the parents after about eight months. Several sightings of adults and juveniles have occurred in Abrams Creek. In 1993, adults with young were observed in Hazel Creek and at Elkmont (DeLozier, personal communication).

• Longevity
  Most otters live about eight or nine years in the wild (Linzey, 1998).

• Terrestrial Ecology
  Although otters may be active day or night during all seasons, they are secretive and are seldom seen. The dense, oily fur and heavy layer of body fat under the skin provide insulation during the colder months. Otters are excellent swimmers and divers and can remain submerged for several minutes. They can also move well on land.

  Crayfish and fish are the primary foods of otters in the park (Griess, 1987; Miller, 1992). Northern hogsuckers (Hypentelium nigricans), white suckers (Catostomus commersoni), and stonerollers (Campostoma anomalum) were the most frequent fishes consumed by these expert fishermen. Other foods include aquatic crustaceans, insects, and frogs.

• Predators and Defense
  Humans are the most important predators on the otter.

• Parasites
  None recorded from the park.

• University of Michigan, Museum of Zoology

Index

Acknowledgements

• Text
  • Dr. Donald W. Linzey, Wytheville Community College - wclinzd@wcc.vccs.edu
  • Christy Brecht, Wytheville Community College - wcbrecc@wcc.vccs.edu

• Photographs
  • Roger Barbour

• Map development
  • Richard Schulz, Great Smoky Mountains National Park - richard_schulz@nps.gov

• Web page design & coding
  • Denise Lim, University of Georgia, Athens
  • John Pickering, University of Georgia, Athens

• Buckley, S. B. 1859. Mountains of North Carolina and Tennessee. American Journal of Science and Arts, 2nd Series, 27: 286-294.

• Griess, J. M. 1987. River otter reintroduction in Great Smoky Mountains National Park. Master's thesis, University of Tennessee, Knoxville, Tennessee.

• King, W. 1934-38. Journal of Willis King, Great Smoky Mountains National Park, for the period May, 1934-March 30, 1938.

• Linzey, A.V., and D.W. Linzey. 1971. Mammals of Great Smoky Mountains National Park. Knoxville: University of Tennessee Press.

• Linzey, D. W. 1995a. Mammals of Great Smoky Mountains National Park. Blacksburg, Virginia: The McDonald & Woodward Publishing Company, Inc.

• Linzey, D. W. 1995b. Mammals of Great Smoky Mountains National Park-1995 Update. Journal of the Elisha Mitchell Scientific Society 111(1):1-81.

• Linzey, D. W. 1998. The Mammals of Virginia. Blacksburg, Virginia: The McDonald & Woodward Publishing Company, Inc.

• Miller, M. C. 1992. Reintroduction of river otters into Great Smoky Mountains National Park. Master's thesis, University of Tennessee, Knoxville, Tennessee.

• Rhodes, S. N. 1896. Contributions to the zoology of Tennessee. Number 3: Mammals. Proceedings of the Philadelphia Academy of Natural Sciences 48: 175-205.

• Stupka, A. 1935-63. Nature Journal, Great Smoky Mountains National Park. 28 volumes (years) each with index. (Typewritten copy in files of Great Smoky Mountains National Park.)

• Williams, S. C. 1948 (1927). Lieut. Henry Timberlake's Memoirs 1756-1765. Continental Book Co., Marietta, GA.