Index of Species Information

WILDLIFE SPECIES:  Lutra canadensis

Introductory

WILDLIFE SPECIES: Lutra canadensis
AUTHORSHIP AND CITATION : Tesky, Julie L. 1993. Lutra canadensis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [].
ABBREVIATION : LUCA COMMON NAMES : northern river otter river otter Canadian otter land otter fish otter TAXONOMY : The currently accepted scientific name for the northern river otter is Lutra canadensis Schreber. (Lutrinae). Nineteen subspecies have been recognized by Hall and Kelson [10] and are listed below: Lutra canadensis ssp. canadensis Schreber Lutra canadensis ssp. brevipilosus Grinnell Lutra canadensis ssp. chimo Anderson Lutra canadensis ssp. degener Bangs Lutra canadensis ssp. evexa Goldman Lutra canadensis ssp. extera Goldman Lutra canadensis ssp. interior Swenk Lutra canadensis ssp. kodiacensis Goldman Lutra canadensis ssp. lataxina F. Cuvier Lutra canadensis ssp. nexa Goldman Lutra canadensis ssp. optiva Goldman Lutra canadensis ssp. pacifica Rhoads Lutra canadensis ssp. periclyzomae Elliot Lutra canadensis ssp. preblei Goldman Lutra canadensis ssp. sonora Rhoads Lutra canadensis ssp. texensis Goldman Lutra canadensis ssp. vaga Bangs Lutra canadensis ssp. vancouverensis Goldman Lutra canadensis ssp. yukonensis Goldman A taxonomic revision of the Lutrinae was done by van Zyll de Jong, who recommended consolidating the above nineteen subspecies and the Prince of Wales Island form (Lutra mira Goldman) into seven subspecies of Lutra canadensis, but leaving the southern river otter (Lutra annectens) as a separate species [4]. ORDER : Carnivora CLASS : Mammal FEDERAL LEGAL STATUS : Not listed OTHER STATUS : Information on state- and province-level protection status of animals in the United States and Canada is available at NatureServe, although recent changes in status may not be included.

WILDLIFE DISTRIBUTION AND OCCURRENCE

WILDLIFE SPECIES: Lutra canadensis
GENERAL DISTRIBUTION : The northern river otter historically occurred over much of the North American continent. Present distribution of the northern river otter extends from 25 degrees N. in Florida to beyond 70 degrees N. in Alaska, and from eastern Newfoundland to the Aleutian Islands [4]. Northern river otters have been extirpated or are rare in Arizona, Colorado, Indiana, Iowa, Kansas, Kentucky, Nebraska, New Mexico, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Utah, and West Virginia. They are still relatively abundant along the coasts of the Atlantic Ocean and the Gulf of Mexico, throughout the Pacific Northwest and Great Lakes states, and across most of Canada and Alaska. Populations are listed as stable or increasing in Alabama, Alaska, Arkansas, Connecticut, Delaware, Florida, Georgia, Idaho, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Montana, New Hampshire, New York, North Carolina, Oregon, Rhode Island, Texas, Vermont, Washington, and Wisconsin [4]. ECOSYSTEMS : FRES10 White-red-jack pine FRES11 Spruce-fir FRES17 Elm-ash-cottonwood FRES18 Maple-beech-birch FRES19 Aspen-birch FRES20 Douglas-fir FRES21 Ponderosa pine FRES22 Western white pine FRES23 Fir-spruce FRES28 Western hardwoods FRES36 Mountain grasslands FRES37 Mountain meadows FRES41 Wet grasslands STATES :
AL AK AZ AR CA CO CT DE FL GA
ID IL IN IA KS KY LA ME MD MA
MI MN MS MO MT NE NV NH NJ NM
NY NC ND OH OK OR PA RI SC SD
TN TX UT VT VA WA WV WI WY
AB BC MB NB NF NT NS ON PE PQ
SK YK
BLM PHYSIOGRAPHIC REGIONS : 1 Northern Pacific Border 2 Cascade Mountains 3 Southern Pacific Border 4 Sierra Mountains 5 Columbia Plateau 6 Upper Basin and Range 7 Lower Basin and Range 8 Northern Rocky Mountains 9 Middle Rocky Mountains 10 Wyoming Basin 11 Southern Rocky Mountains 12 Colorado Plateau 13 Rocky Mountain Piedmont 14 Great Plains 15 Black Hills Uplift 16 Upper Missouri Basin and Broken Lands KUCHLER PLANT ASSOCIATIONS : K005 Mixed conifer forest K011 Western ponderosa forest K012 Douglas-fir forest K015 Western spruce - fir forest K020 Spruce - fir - Douglas-fir forest K021 Southwestern spruce - fir forest K025 Alder - ash forest K026 Oregon oakwoods K028 Mosaic of K002 and K026 K030 California oakwoods K047 Fescue - oatgrass K049 Tule marshes K050 Fescue - wheatgrass K051 Wheatgrass - bluegrass K063 Foothills prairie K073 Northern cordgrass prairie K078 Southern cordgrass prairie K080 Marl - everglades K092 Everglades K093 Great Lakes spruce - fir forest K094 Conifer bog K095 Great Lakes pine forest K096 Northeastern spruce - fir forest K097 Southeastern spruce - fir forest K098 Northern floodplain forest K101 Elm - ash forest K106 Northern hardwoods K107 Northern hardwoods - fir forest K108 Northern hardwoods - spruce forest SAF COVER TYPES : 16 Aspen 18 Paper birch 19 Gray birch - red maple 20 White pine - northern red oak - red maple 24 Hemlock - yellow birch 25 Sugar maple - beech - yellow birch 30 Red spruce - yellow birch 31 Red spruce - sugar maple - beech 35 Paper birch - red spruce - balsam fir 39 Black ash - American elm - red maple 51 White pine - chestnut oak 62 Silver maple - American elm 93 Sugarberry - American elm - green ash 95 Black willow 202 White spruce - paper birch 204 Black spruce 203 Balsam poplar 210 Interior Douglas-fir 212 Western larch 217 Aspen 222 Black cottonwood - willow 235 Cottonwood - willow 241 Western live oak 244 Pacific ponderosa pine - Douglas-fir 245 Pacific ponderosa pine 246 California black oak 249 Canyon live oak 252 Paper birch 255 California coast live oak SRM (RANGELAND) COVER TYPES : NO-ENTRY PLANT COMMUNITIES : Northern river otters inhabit a variety of riparian plant communities. These communities are often dominated by willows (Salix spp.), cottonwoods (Populus spp.), birches (Betula spp.), and spruce (Picea spp.). Other vegetation common in northern river otter habitats includes cattails (Typha spp.), red-osier dogwood (Cornus sericea), black hawthorn (Crataegus douglassi), common snowberry (Symphoricarpos albus), grasses, horsetails (Equisetum spp.), bulrushes (Scirpus spp.), and sedges (Carex spp.) [3,6,19].

BIOLOGICAL DATA AND HABITAT REQUIREMENTS

WILDLIFE SPECIES: Lutra canadensis
TIMING OF MAJOR LIFE HISTORY EVENTS : Breeding - Northern river otters breed in late winter or early spring; the breeding season is spread over a period of 3 months or longer [1,4]. Gestation period and litter size - There is much discrepancy in the literature regarding the length of gestation in the northern river otter. Gestation periods of 288 to 375 days have been reported. The extreme length of gestation is due to a process called "delayed implantation", wherein the development of the blastocyst is arrested for a period of time before it implants into the uterine wall. Litters are generally born from November through May. In northwestern North America, river otters generally give birth from March through May following an average delay of 9 months and an actual gestation of about 62 days [6]. Litter size ranges from one to six, with two to four young most common [4]. Pup development - Northern river otter pups are born helpless. They begin to open their eyes by age 21 to 35 days; by 25 to 42 days pups begin playing. Northern river otter pups are introduced to water by age 48 days and may venture out of the den on their own by the age of 59 to 70 days. Weaning occurs at about 91 days of age [4]. Age at sexual maturity - Female northern river otters normally become sexually mature when they are about 2 years old, but may or may not breed at that time. Female northern river otters may not breed every year [6,14]. Although male northern river otters also become sexually mature at about 2 years of age, they may not become successful breeders until they reach 5 to 7 years [4]. Life span - Northern river otters have lived at least 16 years in captivity [1]. Northern river otters are primarily nocturnal, but may be active in the early morning and late afternoon in remote areas. They are active all winter except during the most severe periods, when they take shelter for a few days [1]. PREFERRED HABITAT : Northern river otters are adapted to a variety of aquatic habitats from marine environments to high-elevation mountain lakes. Optimum habitat for northern river otters includes slow-moving water with deep pools, abundant riparian vegetation, and plentiful fish [6]. Northern river otters are generally most abundant along food-rich coastal areas, such as the lower portions of streams and rivers and in estuaries, and in areas having extensive nonpolluted waterways [4]. In Canada, they occur north beyond the tree line in tundra lakes and streams [1]. Melquist and Hornocker [14] found that in west-central Idaho, river otters prefer valley habitats to mountain habitats, and prefer streamassociated habitats to lake, reservoir, and pond habitats. Mountain lakes and streams were used most often during the fall. Most northern river otters lived entirely in the valleys, and no otters lived solely in the mountains. The use of lakes, reservoirs, and ponds was greatest during the winter. Mudflats and associated open marshes, swamps, and backwater sloughs were used most often in summer [14]. Northern river otter habitat is generally limited to open water during the winter months. Outflows from lakes are favored habitat at this time. In late winter, water levels usually drop below ice levels in rivers and lakes, leaving a layer of air that allows northern river otters to travel and hunt under the ice [16]. COVER REQUIREMENTS : Northern river otter habitat must provide adequate escape cover, rest sites, and den sites. Rather than excavate their own dens, northern river otters use dens dug by other animals, or natural shelters. They commonly use hollow trunks of large trees, beaver (Castor canadensis) or nutria (Myocastor coypus) dens, hollow logs, log jams, drift piles, jumbles of loose rocks, abandoned or unused boathouses, and duck blinds [4]. Occasionally northern river otters occupy large, bulky, open nests of grasses in marshes or riverbank thickets [1]. Understory bank cover is also important to northern river otters. In a study of northern river otter habitat in northwestern Montana, areas with less than 25 percent understory bank cover were used significantly less than expected based on availability [6]. Stream habitats generally provide more adequate escape cover and shelter and less human disturbance than pond, lake, and reservoir habitats [16]. FOOD HABITS : The typical diet of northern river otters consists primarily of fish, but also includes crustaceans (primarily crayfish), amphibians, insects, birds, mammals, and plants [4,5,13]. Although a wide variety of fish species are eaten by northern river otters, some species of fish are more vulnerable to northern river otter predation. Slow-swimming fish species are generally selected by northern river otters more often than fast-swimming fishes. Also important are fish species that are abundant and found in large schools [4]. Fishes often eaten by northern river otters include suckers (Catostomus spp.), redhorses (Moxostoma spp.), carp (Cyprinus spp.), chubs (Semotilus spp.), daces (Phinichthys spp.), shiners (Notropis spp.), squawfish (Ptychocheilus spp.), bullheads and catfish (Ictalurus spp.), sunfish (Lepomis spp.), darters (Etheostoma spp.), and perch (Perca spp.). Crayfish (Cambarus spp., Pacifasticus spp., and others) also comprise a major portion of the northern river otter's diet [1,4]. Waterfowl and rails comprise an important part of the northern river otter diet in the Pacific Coast states and in many other regions. Freshwater mussels (Anodonta californiensia), freshwater periwinkles (Oxytrema silicula), and unidentified clams and snails have been reported in the northern river otter's diet but are not important food items [4]. Northern river otters may kill young beavers found alone in a lodge [1]. PREDATORS : Although essentially safe from predators while in water, northern river otters are considerably more vulnerable when they travel overland between lakes, ponds, and steams [14]. Bobcats (Felis rufus), dogs (Canis familiaris), coyotes (C. lutrans), foxes, gray wolves (C. lupus), and American alligators (Alligator mississippiensis) have all been reported to kill northern river otters [4,14,15]. In addition, it is likely that other predators, including cougars (F. concolor), black bears (Ursus americanus), American crocodiles (Crocodylus acutus), and some large raptors, also kill northern river otters on occasion. No predator has been shown to have a serious impact on northern river otter populations, and most predation is probably directed toward young northern river otters [4]. MANAGEMENT CONSIDERATIONS : Northern river otters have often been blamed for serious depredation of game fish, particularly trout. Food habit studies, however, have all indicated that the bulk of the northern river otter diet consists of nongame fish species. In many circumstances, northern river otters are beneficial to game fish populations because they remove nongame fish that would otherwise compete with game fish for food [4]. Northern river otters, however, may occasionally cause severe depredation in fish hatcheries [1,4]. Northern river otters have been extirpated or reduced in many areas due to human encroachment, habitat destruction, and overharvest [8]. Northern river otters are relatively abundant in major nonpolluted river systems and in the lakes and tributaries that feed them. They are scarce, however, in heavily settled areas, particularly if the waterways are polluted. In Maryland, no northern river otters occur in waters altered by acidic mine drainages. The disappearance of northern river otters from West Virginia and parts of Tennessee and Kentucky has been attributed to increased acidity of ground water due to mining operations [4]. Little research has been done in evaluating the range of water quality that otters will tolerate [4] The most readily apparent human impact on northern river otters results from trappers harvesting otters for their fur. The northern river otter has been an economically important furbearing species since Europeans first arrived in North America [4]. Habitat destruction has also resulted in a decline in northern river otter populations. Some causes of northern river otter habitat destruction include the development of waterways for economic or recreational purposes, destruction of riparian habitat for homesites or farmland, and a decline in water quality because of increased siltation and/or pesticide residues in runoff [4,6,16]. Pesticide residues including mercury, DDT and its metabolites, and Mirex have been reported in northern river otter tissues [4]. Roads and railroad tracks that parallel or cross streams are probably responsible for a considerable number of northern river otter deaths each year. This is an important consideration in mountainous states where roads are constructed along stream courses [14]. Several researchers have associated good northern river otter habitat with the activities of beavers. Northern river otter population dynamics may be influenced not only by beaver trapping but also by wide fluctuations in beaver numbers and subsequent habitat changes. In the western United States, with its widely separated waterways and large variations in flow, beaver-created habitat may be critical to northern river otter denning and foraging [6]. A variety of internal parasites affect northern river otters. Of these, two roundworms (Stronguloides lutrae and Gnathostoma miyazakii) may cause serious pathological damage. Northern river otters are also susceptible to canine distemper, jaundice, hepatitis, and feline panleucopenia [4]. In recent years several states have transplanted northern river otters in an attempt to establish or reestablish breeding populations [17].

FIRE EFFECTS AND USE

WILDLIFE SPECIES: Lutra canadensis
DIRECT FIRE EFFECTS ON ANIMALS : No information was found in the literature regarding the direct effect of fire on northern river otters; however, they can probably easily escape fire. The aquatic habitats in which they occur will generally provide good escape cover. HABITAT RELATED FIRE EFFECTS : The short-term effects of a riparian fire may affect the northern river otter's food supply. Removal of streamside vegetation increases the risk of streambank erosion and raises stream temperatures, both of which could potentially reduce fish populations in the stream. However, the long-term effect of fire on fish populations could be benefical. Fire thins and removes conifers along streams, stimulates growth of deciduous vegetation. This provides cover and shading, and fosters development of terrestrial insects important in the diet of fishes [20]. Additionally, fire occurring in riparian areas indirectly benefits river otters by benefiting beavers [11]. As stated in MANAGEMENT CONSIDERATIONS, beaver activities help create suitable habitat for river otters. FIRE USE : When burning marshes, partial burns are more desirable than complete burns. The unburned portions of the marsh provide cover for river otters [20].

REFERENCES

WILDLIFE SPECIES: Lutra canadensis
REFERENCES : 1. Banfield, A. W. F. 1974. The mammals of Canada. Toronto, ON: University of Toronto Press. 438 p. [21084] 2. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434] 3. Chabreck, Robert H. 1971. Ponds and lakes of the Louisiana coastal marshes and their value to fish and wildlife. Proceedings, 25th Annual Conference of Southeastern Association of Game and Fish Commissioners: 206-215. [14961] 4. Chapman, Joseph A.; Feldhamer, George A., eds. 1982. Wild mammals of North America. Baltimore, MD: The Johns Hopkins University Press. 1147 p. [21085] 5. Davis, Harry G.; Aulerich, Richard J.; Bursian, Steven J.; [and others]. 1992. Feed consumption and food transit time in northern river otters (Lutra canadensis). Journal of Zoo and Wildlife Medicine. 23(2): 241-244. [18438] 6. Dronkert-Egnew, Ana E. 1991. River otter population status and habitat use in northwestern Montana. Missoula, MT: Univeristy of Montana. 112 p. Thesis. [20339] 7. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 8. Finch, Deborah M. 1992. Threatened, endangered, and vulnerable species of terrestrial vertebrates in the Rocky Mountain Region. Gen. Tech. Rep. RM-215. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 38 p. [18440] 9. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998] 10. Hall, E. Raymond; Kelson, Keith R. 1959. The mammals of North America, Volume II. New York: The Ronald Press Company. 79 p. [21460] 11. Kelleyhouse, David G. 1979. Fire/wildlife relationships in Alaska. In: Hoefs, M.; Russell, D., eds. Wildlife and wildfire: Proceedings of workshop; 1979 November 27-28; Whitehorse, YT. Whitehorse, YT: Yukon Wildlife Branch: 1-36. [14071] 12. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384] 13. Meehan, William R. 1974. The forest ecosystem of southeast Alaska: 4. Wildlife habitats. Gen. Tech. Rep. PNW-16. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 32 p. [13479] 14. Melquist, Wayne E.; Hornocker, Maurice G. 1983. Ecology of river otters in west central Idaho. Wildlife Monographs. 83: 1-60. [19356] 15. Route, William T.; Peterson, Rolf O. 1991. An incident of wolf, Canis lupus, predation on a river otter, Lutra canadensis, in Minnesota. Canadian Field-Naturalist. 105(4): 567-568. [19821] 16. Spowart, Richard A.; Samson, Fred B. 1986. Carnivores. In: Cooperrider, Allan Y.; Boyd, Raymond J.; Stuart, Hanson R., eds. Inventory and monitoring of wildlife habitat. Denver, CO: U.S. Department of the Interior, Bureau of Land Management, Service Center: 475-496. [13526] 17. Tango, Peter J.; Michael, Edwin D.; Cromer, Jack I. 1991. Mating and first-season births in interstate transplanted river otters, Lutra canadensis (Carnivora: Mustelidae). Brimleyana. 17: 53-55. [20686] 18. Van Gelden, Richard George. 1982. Mammals of the National Parks. Baltimore, MD: Johns Hopkins University Press. 310 p. [20893] 19. Waller, Amy Johnston. 1992. Seasonal habitat use of river otters in northwestern Montana. Missoula, MT: University of Montana. 75 p. Thesis. [20659] 20. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. [2620] 21. Herkert, J. R., ed. 1992. Endangered and threatened species of Illinois: status and distribution. Volume 2--Animals. Springfield, IL: Illinois Endangered Species Protection Board. 142 p. [23799] 22. South Dakota Department of Game, Fish and Parks. 1994. Fragile legacy: Endangered, threatened and rare animals of South Dakota. Pierre, SD: South Dakota Department of Game, Fish, and Parks, Wildlife Division. 55 p. [24341] 23. Wingfield, Greg. 1992. Nebraska's vanishing species. Lincoln, NE: Nebraska Game and Parks Commission, Wildlife Division, [Nebraskaland Magazine]. 15 p. [24344] 24. U.S. Department of the Interior, Fish and Wildlife Service. 1994. Endangered and threatened wildlife and plants; animal candidate review for listing as endangered or threatened species; proposed rule. 50 CFR Part 17. Tuesday, November 15, 1994. Federal Register. 59(219): 58982-59028. [24357]


FEIS Home Page