River otters prefer to eat non-game fish species, so in a healthy ecosystem they don’t compete with human fishermen. Scent marking is imperative for intergroup communication. Groups typically travel and hunt together, and also use the same resting site and den. 1. [12] [19] At birth, the North American river otters are fully furred, blind, and toothless. Musk from the scent glands may also be secreted when otters are frightened or angry. North American river otters are very susceptible to the effects of environmental pollution, which is a likely factor in the continued decline of their numbers. River otters eat a variety of aquatic wildlife, such as fish, crayfish, crabs, frogs, birds’ eggs, birds and reptiles such as turtles. Fish is a favored food among the otters, but they also consume various amphibians (such as salamanders and frogs[3]), freshwater clams, mussels, snails, small turtles and crayfish. [39] Remains of the much larger North American beaver have been found in North American river otter scat in some regions, although most otter dietary studies in areas where otters and beaver are sympatric do not show them to be regular predators of beavers (despite the claims of fur-trappers that otters frequently hunt beavers) and perhaps only young beaver kits may be attacked. [9] The species epithet canadensis means "of Canada". [46] In late 2012, a river otter nicknamed Sutro Sam took up residence around the former site of the Sutro Baths in San Francisco, the first river otter sighting in that city in more than half a century. Preceding the settlement of North America by Europeans, North American river otters were prevalent among aquatic habitats throughout most of the continent. [8], The North American river otter was first described by German naturalist Johann Christian Daniel von Schreber in 1777. [27] During winter, the North American river otters heavily use openings in the ice, and may excavate passages in beaver dams for accessing open water. River otters also prefer slower-moving fish to game fish. Water pollution and other diminution of aquatic and wetland habitats may limit distribution and pose long-term threats if the enforcement of water quality standards is not upheld. [15], Threats to North American river otter populations in North America vary regionally. The adult river otters are known to eat 1 – 1.5 kg (2.2 0 3.3 lb) of fish each day. Most of these problems are due to water pollution. The throat, chin, and lips are grayer than the rest of the body. ); darters (Etheostoma spp. These analyses suggest they diverged in the Miocene epoch 23.03 to 5.33 million years ago (Mya), which is "much earlier" than indicated in the fossil record. [14] The earliest known fossil of Lontra canadensis, found in the US Midwest, is from the Irvingtonian stage (1,800,000 to 300,000 years ago). [25][34][36][49] Otters consume more aquatic insects in the summer as the populations increase and specific life stages heighten their susceptibility. In some regions, though, their population is controlled to allow the trapping and harvesting of otters for their pelts. It must remain in motion to maintain its position at the surface. [28] Otters are known to take larger fish on land to eat, whereas smaller fish are consumed in the water. In all habitats, their basic social group is the family, consisting of an adult female and her progeny. The young eat mainly invertebrates, such as insects, insect larvae, snails, spiders and worms. [22] Den sites include burrows dug by woodchucks (Marmota monax), red foxes (Vulpes vulpes), nutria (Myocastor coypus), or beaver and muskrat lodges. [34][49] Invertebrates discovered within scats or digestive tracts could most likely be a secondary food item, first being consumed by the fish that are subsequently preyed upon by the North American river otters. They have also been known to eat aquatic plants and to prey on other small mammals, such as muskrats or rabbits. They host numerous endoparasites, such as nematodes, cestodes, trematodes, the sporozoan Isopora, and acanthocephalans. [10], The North American river otter was first classified in the genus Lutra; Lutra was the early European name. North American river otters also inhabit the forested regions of the Pacific coast in North America. The river otter food web plays a crucial role in the environments the river otter calls home. They have been virtually eliminated through many parts of their range, especially around heavily populated areas in the midwestern and eastern United States. Both males and family groups travel drastically less during winter. Normally, during a winter here at John Ball Zoo, our North American river otters can still be on exhibit in the cold and snow. Breeding is from December to April: late winter or early in spring. [18] An average adult male weighs about 11.3 kilograms (25 lb) against the female's average of 8.3 kilograms (18 lb). However, it is sensitive to pollution, and will disappear from tainted areas. The main diet of the otter is made up of fish and crustaceans. These include game fishes, bass (Centrarchidae) suckers (Catostomidae), and shiners. The giant river otters have also been noted to feed on small anacondas and caimans. Therefore, fish are more vulnerable to being preyed upon by otters because the crayfish have become more difficult to obtain. There is no significant threat today from commercial harvesting, but illegal hunting can affect local populations. Terrestrial predators include the bobcat (Lynx rufus), mountain lion (Puma concolor), coyote (Canis latrans), domestic dog (Canis lupus familiaris), wolf (Canis lupus), black bear (Ursus americanus) and (in young or small North American river otters) red fox (Vulpes vulpes) . [15] Females may caterwaul during or shortly after mating. The North American river otter is the only otter species not facing population decline on a large scale. Edit our stories only to reflect references to time (e.g. Since their reintroduction to Kentucky in the early 90s, they have recovered to the point that a trapping season was started in 2006, and the species is now found in all major waterways. Moreover, a western Oregon study revealed fish remains were present in 80% of the 103 digestive tracts examined. They hunt singly or in pairs and although otters generally forage in water, they are equally at home on land, sometimes traveling between 10 and 18 miles (16 and 29 kilometers) in search of food. [19] About one-third of the animal's total length consists of a long, tapered tail. Pups will open their eyes when they are one month old and are weaned when about 3 months old, starting to leave their birth range from 6 months to the age of one year. The North American river otter has many natural predators but typically can avoid them by escaping quickly to a burrow or to water. Otters have a long body covered in soft brown fur. North American river otters also may use hollow trees or logs, undercut banks, rock formations, backwater sloughs, and flood debris. [15] On land or ice, the North American river otter is considerably more vulnerable. [30][38] North American river otters do not generally handle prey of a large size relative to themselves but there are occasions where they've been observed ambushing and killing adult common snapping turtles while the large turtles (which are roughly equal in average body weight to a North American river otter) are hibernating. North American river otters seem to be sensitive to pollution and disappear from areas with polluted waters. Declines in the richness and diversity of prey species may explain these changes. An adult North American river otter can weigh between 5.0 and 14 kg (11.0 and 30.9 lb). Sliding occurs mostly on even surfaces of snow or ice, but can also occur on grassy slopes and muddy banks. [15], The mothers raise their young without aid from adult males. Reduced lobulation of the lungs is presumed to be adaptive for underwater swimming. Aquatic predators include the American alligator (Alligator mississippiensis), American crocodile (Crocodylus acutus), and killer whale (Orcinus orca), none of which commonly coexist with the North American river otter and thus rarely pose a threat. [52], Waterfowl, rails, and some colonial nesting birds are preyed upon by North American river otters in various areas. [32][36] Slow-moving species include suckers (Catostomidae), catfish, sunfish and bass (Centrarchidae), daces, carp, and shiners (Cyprinidae). They uses their long whiskers to detect prey underwater. [10], The North American river otter is a stocky animal of 5 to 14 kilograms (11 to 31 lb), with short legs, a muscular neck (no smaller than the head) and an elongated body that is broadest at the hips. On occasion, groups of unrelated juveniles are observed. [9] The mammal was identified as a species of otter and has a variety of common names, including North American river otter, northern river otter, common otter and, simply, river otter. They can live in freshwater and coastal marine habitats, including rivers, lakes, marshes, swamps, and estuaries. These furry water lovers hunt mostly at night, following the scent of fish even into urban areas. streams, lakes, wetlands) along marine coasts in the United States and Canada, including parts of the Pacific Northwest. Likewise, the potential predatory impact of otters may be considerable whenever fish are physically confined (most commonly in smaller ponds offering sparse cover or other escape options). Outside of fish, river otters will also eat crustaceans, insects, birds, oysters, shellfish, turtles and a number of other aquatic life. [49] The few occurrences of mammals found in the North American river otter's diet include: muskrats (Ondatra zibethicus); meadow voles (Microtus pennsylvanicus); eastern cottontails (Sylvilagus floridanus); and snowshoe hares (Lepus americanus). The North American river otters are carnivores, they eat mainly aquatic animals such as amphibians, turtles, fish, crayfish, crabs, and other species of invertebrates. If fish numbers start to decrease or they move elsewhere as a result of climate change, this species would lose its major food source. The most common fish consumed are perch, suckers, and catfish. North American river otters have transparent nictitating membranes to protect their eyes while swimming. Although the distribution became reduced in some regions of southern Canada, the only province-wide extirpation occurred on Prince Edward Island. Otters have the thickest fur of any mammal, having as many as 850,000 hairs per square inch. Birds, their eggs, and small terrestrial mammals are also eaten on occasion. [15], North American river otters consume an extensive assortment of fish species ranging in size from 2 to 50 centimeters (0.79 to 19.69 in) that impart sufficient caloric intake for a minute amount of energy expenditure. This animal’s lovely waterproof pelt, which allows it to regulate its temperature, in the 1700s-1800s, a regular part of French fur trade, has meant this animal has been hunted for hundreds of years. Male North American river otters do not seem to be territorial, and newly dispersing males may join established male groups. [15], CS1 maint: multiple names: authors list (, "Expert says otter attacks are rare after St. Pete dog killed", "Dog attacked by otters in Lakewood, homeowners say", "7 Surprising Facts About the Giant River Otter", "Multigene phylogeny of the Mustelidae: Resolving relationships, tempo and biogeographic history of a mammalian adaptive radiation", 10.1644/1545-1410(2002)712<0001:LM>2.0.CO;2, "North American River Otter – National Wildlife Federation", "Basic Facts About North American River Otters", "Distribution and abundance of river otter in Voyageurs National Park, Minnesota", "Food habits of the river otter in Suisun Marsh, Central California", "Feeding relationships of river otters in northeastern Pennsylvania", Food habits of the North American river otter (, "Social Networks and the Formation and Maintenance of River Otter Groups", "Art Lander's Outdoors: Once endangered river otters now likely to be found in Kentucky for generations", Colorado Otters May No Longer Need Protection, "Final report of the North American river otter research project on the Upper Colorado River Basin in and adjacent to Rocky Mountain National Park, Colorado", https://animaldiversity.org/accounts/Lontra_canadensis/, COSEWIC assessment and status report on the Grizzly Bear, https://en.wikipedia.org/w/index.php?title=North_American_river_otter&oldid=992972571, Articles with unsourced statements from May 2009, Creative Commons Attribution-ShareAlike License, This page was last edited on 8 December 2020, at 02:59. Environmental disasters, such as oil spills, may increase levels of blood haptoglobin and interleukin-6 immunoreactive protein, but decrease body mass. North American river otter inhabitation is affected by type, distribution, and density of aquatic habitats and characteristics of human activities. An entrance, which may be under water or above ground, leads to a nest chamber lined with leaves, grass, moss, bark, and hair. ); and perches (Perca spp.). The North American river otters may compete with the American mink (Mustela vison) for resources. It establishes a burrow close to the water's edge in river, lake, swamp, coastal shoreline, tidal flat, or estuary ecosystems. Sometimes they eat aquatic plants. In Maine, use of watersheds by North American river otters is negatively associated with the proportion of mixed hardwood-softwood stands in forested areas adjacent to waterways. They remain active in winter, using ice holes to surface and breathe. [13] Fossils of a giant river otter dating back 3.5 Mya have been found in the US Midwest; however, fossils of the modern river otter did not appear in North America until about 1.9 Mya. [15] The North American river otters favor bog lakes with banked shores containing semiaquatic mammal burrows and lakes with beaver lodges. A female gives birth to 1 to 6 young in each litter, averaging 2 to 3. North American river otters tend to have spraint sites at vantage points, such as under bridges, on prominent rocks at the seashore, and near trees. The river otter food chain also consists of mussels, bivalves, snails, cr… [15], The North American river otter is physically well-equipped for aquatic life. [36] A study conducted on captive otters revealed they preferred larger fish, ranging from 15 to 17 centimeters (5.9 to 6.7 in), more than smaller fish, ranging from 8 to 10 centimeters (3.1 to 3.9 in), and they had difficulty catching fish species less than 10 centimeters (3.9 in) or larger than 17 centimeters (6.7 in). Male North American river otters disperse from such family groups more often than females. in hatcheries or other fish culture facilities). [33] Every study done on the food habits of the North American river otter has identified varying fish species as being the primary component of its diet. North American river otters are known for their playful swimming, but they are also an important species for helping scientists understand the health of river systems. [25] Other fish an integral part of the North American river otters' diets are those that are often plentiful and found in large schools: sunfish (Lepomis spp. [30] However, river otters will prey on trout, pike, walleye (Sander vitreus vitreus), salmon (Oncorhynchus spp. North American otters are polygynous, with males often breeding with several females, probably ones whose home ranges overlap theirs. These otters have all webbed feet that allow them to be active, playful swimmers! North American river otter (or common otter): Found in and along North America’s waterways and coasts, these otters weigh between 11 and 31 lbs (5-14kg). North American River Otter on The IUCN Red List site -, https://en.wikipedia.org/wiki/North_American_river_otter, http://www.iucnredlist.org/details/12302/0. Currently this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today remain stable. As the front feet make contact with the ground, the back feet are lifted and land where the front paws first contacted the ground, producing a pattern of tracks in pairs typical of most mustelids. Several North American river otters may even cooperate while fishing. Reintroduction projects have expanded their distribution in recent years, especially in the Midwestern United States. The Defenders of Wildlife resource, based on harvest reports, estimates the North American otter’s total population size to be over 100,000 individuals. [15], Aquatic life ties North American river otters almost exclusively to permanent watersheds. [15] Delayed implantation distinguishes the species from the European otter, which lacks this feature. In many places, the populations have re-established themselves because of conservation initiatives. Otters usually hide and launch surprise, lunging attacks on their prey. The North American river otter has many natural predators but typically can avoid them by escaping quickly to a burrow or to water. North American river otters also may use a birdlike chirp for communication over longer distances, but the most common sound heard among a group of otters is low-frequency chuckling. Even in larger bodies of water, they may take disproportional advantage of any seasonal concentrations of fish when and where only very limited areas of suitable spawning, low-flow, or over-wintering habitat may exist. Copulation lasts from 16 to 73 minutes and may occur in water or on land. Live fish are typically eaten from the head. Family groups may include helpers, which can be made up of unrelated adults, yearlings, or juveniles. A North American river otter's main requirements are a steady food supply and easy access to a body of water. [11], In a new classification, the species is called Lontra canadensis, where the genus Lontra includes all the New World river otters. Food. [30][31] Mammals preyed upon by North American river otters are characteristically small or are a type species found in riparian zones. Fur of senescent river otters may become white-tipped, and rare albinos may occur. North American River Otter Wikipedia article -, 2. Otters will also use hollowed-out or natural hollows found along river banks and lakeshores and seem to prefer densely-wooded areas. In addition, riverine habitats in interior regions supported smaller, but practical, otter populations. A number of reintroduction projects have been initiated to help halt the reduction in the overall population. Acid drainage from coal mines is a persistent water quality issue in some areas, as it eliminates otter prey. North American river otters living in groups hunt and travel together, use the same dens, resting sites, and latrines, and perform allogrooming. When at play or traveling, they sometimes give off low, purring grunts. and redhorses (Moxostoma spp. [15] North American otters are playful animals, and indulge in water play, mud/snow sliding, and burrowing through snow. In addition, North American river otters can contract jaundice, hepatitis, feline panleucopenia, and pneumonia. River otters can tolerate a variety of environments, including cold and warmer latitudes and high elevations. [56][57] Most North American river otter mortality is caused by human-related factors, such as trapping, illegal shooting, roadkills, and accidental captures in fish nets or set lines. Adult males also commonly establish enduring social groupings, some documented to comprise as many as 17 individuals. Its fur ranges in color from white and gray to brown and black. North American river otters are not scavengers; they avoid consuming carrion. [22] Males are, on average, 5% larger than females. North American river otter pelts are used as the standard for rating the quality of other pelts. [25], The North American river otter is more social than most mustelids. Births take place from November to May, peaking in March and April. In warmer months, they are most active between dusk and dawn. Historically, these animals were hunted for their coats. North American river otter (or common otter): Found in and along North America’s waterways and coasts, these otters weigh between 11 and 31 lbs (5-14kg). Prior to the arrival of the next litter, the North American river otter yearlings venture out in search of their own home ranges.[44]. Hollows in the banks of ponds and rivers make excellent dens and so do former Beaver lodges. However, urbanization and pollution instigated reductions in range area. It is not uncommon for anglers to have to fight river otters for their bait. When the mothers have established their domains, they give birth to several kits. These animals have boundless energy due to their very high metabolism. Northern American otters are able to close their nostrils in order to keep water out when diving for a long time. The North American otter inhabits much of the United States and Canada, from the Pacific to the Atlantic Coast, from the Gulf of Mexico to northern Alaska. [19] Large male North American river otters can exceed a weight of 15 kilograms (33 lb). These qualities give the North American river otter a streamlined profile in water, but reduce agility on land. [49] Fish species frequently found in the diets of the North American river otters include: Catostomidae, which consists of suckers (Catostomus spp.) Fur of the North American river otter is thick and lustrous and is the most durable of Native American furs. [34] Other species of birds found within their diets include: northern pintail (Anas acuta); mallard (Anas platyrhynchos); canvasback (Aythya valisineria); ruddy duck (Oxyura jamaicensis); and the American coot (Fulica americana). [25] When left unchecked, though, otter depredations can be quite significant under certain circumstances (e.g. North American river otters get their boundless energy from their very high metabolism, which also requires that they eat a great deal during the day. North American river otters also currently inhabit coastal regions throughout the United States and Canada. Sea otters breed throughout the year. [54] Trappers in Alberta, Canada commonly assert North American river otters are major predators of North American beavers. The most severe population declines occurred in interior regions where fewer aquatic habitats supported fewer otter populations. Diet of the River Otter. [15] Tail lengths range from 30 to 50 centimetres (12 to 20 in). [1], Lontra canadensis is listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. [48] However, large populations never occurred in areas of Southern California such as the chaparral and oak woodlands and Mojave Desert seasonal waterway regions, or in the xeric shrubland regions in New Mexico, Texas, Nevada, and Colorado. When the pups are about two months old and their coats grow in, their mother introduces them to the water. [35] However, North American river otters, as foragers, will immediately take advantage of other prey when readily obtainable. However, it is sensitive to pollution, and will disappear from tainted areas. Prey is captured with a quick lunge from ambush, or more rarely, after a sustained chase. The spraint sites of the otters along the Alaskan coast are large, with very prominent “ heaps of scats ” over huge areas, near holts (otter … They sometimes eat aquatic plants. ); and Ictaluridae, which consists of bullheads and catfish (Ictalurus spp.). North American River Otters. [15], North American river otters are renowned for their sense of play. In Alaska, the two species living in marine environments indicate niche separation through resource partitioning, probably related to the swimming abilities of these mustelids. Birds and birds’ eggs, as well as small terrestrial mammals may also be eaten. The river otter food chain consists mostly of fish. They become much more nocturnal in the spring, summer, and fall seasons, and more diurnal during winter. Males may breed with more than one female during the year. [45] In 2010, the Colorado Department of Wildlife reported the species, reintroduced in the 1980s, was "thriving" and recommended its protection status be reconsidered. The North American river otters avoid water bodies with gradually sloping shorelines of sand or gravel. North American otters are able to dive as deep as 60 feet. Zookeeper Samantha introduces us to 2 adorable residents of the … The only continents without otters are Australia and Antarctica. Daily movements of family groups averaged 4.7, 4.4, and 2.4 km (2.9, 2.7, and 1.5 mi) in spring, summer, and winter, respectively. River Animals and Harsh Winter Conditions North American River Otter. In freshwater systems, groups occur most often in autumn and during early winter. It is not uncommon for anglers to have to fight river otters … Chasing is also a common game. They reach reproductive maturity at the age of 2 to 3 years. Fish are the primary component of the North American river otter's diet throughout the year. Home ranges of North American river otters increase in size on oiled areas compared to unoiled areas, and individual otters also modify their habitat use. While current harvest strategies do not pose a threat to maintaining otter populations, harvest may limit expansion of otter populations in some areas. During walking, the limbs are moved in a plane parallel to the long axis of the body. These include mudminnows (Umbra limi) and sculpins (Cottus spp.). In coastal areas, males may remain gregarious even during the estrous period of females. It can tolerate a great range of temperature and elevations. [9] Other documented common names are American otter, Canada otter, Canadian otter, fish otter, land otter, nearctic river otter, and Prince of Wales otter. However, North American river otters remain rare or absent in the southwestern United States. Accidental deaths may be the result of ice flows or shifting rocks. [33] Crustaceans (crayfish), where regionally available, are the second-most important prey for otters. Female North American river otters give birth in these burrows, producing litters of one to six young. [51] A study conducted on North American river otters in a southwestern Arkansas swamp identified a correlation between crayfish consumption, fish consumption, and water levels. [33] Specific species of reptiles and amphibians prey include: boreal chorus frogs (Pseudacris maculata); Canadian toads (Bufo hemiophrys); wood frogs (Rana sylvatica);[34] bullfrogs (Rana catesbeiana); green frogs (Rana clamitans);[36] northwestern salamanders (Ambystoma gracile); Pacific giant salamander (Dicamptodon ensatus); rough-skinned newt (Taricha granulosa);[33] and garter snakes (Thamnophis).

what do north american river otters eat

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