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The otters form the subfamily Lutrinae within the mustelids and the giant otter is the only member of the genus Pteronura. Two subspecies are currently recognized by the canonical Mammal Species of the World , P. Incorrect descriptions of the species have led to multiple synonyms the latter subspecies is often P. Carter and Rosas, however, rejected the subspecific division in , noting the classification had only been validated once, in , and the P.
An extinct genus, Satherium , is believed to be ancestral to the present species, having migrated to the New World during the Pliocene or early Pleistocene.
The giant otter seems to have evolved independently of Lontra in South America, despite the overlap. The smooth-coated otter Lutrogale perspicillata of Asia may be its closest extant relative; similar behaviour, vocalizations, and skull morphology have been noted. Phylogenetic analysis by Koepfli and Wayne in found the giant otter has the highest divergence sequences within the otter subfamily, forming a distinct clade that split away 10 to 14 million years ago.
They noted that the species may be the basal divergence among the otters or fall outside of them altogether, having split even before other mustelids, such as the ermine , polecat , and mink. The giant otter is large, gregarious, and diurnal. Early travellers' reports describe noisy groups surrounding explorers' boats, but little scientific information was available on the species until Duplaix's groundbreaking work in the late s.
The giant otter is clearly distinguished from other otters by morphological and behavioural characteristics. It has the greatest body length of any species in the mustelid family, although the sea otter may be heavier. Males are between 1. Giant otter muzzles are short and sloping and give the head a ball-shaped appearance.
The giant otter's highly sensitive whiskers vibrissae allow the animal to track changes in water pressure and currents, which aids in detecting prey. Well suited for an aquatic life, it can close its ears and nose while underwater.
The giant otter or giant river otter (Pteronura brasiliensis) is a South American carnivorous mammal. It is the longest member of the Mustelidae, or weasel family . Fish make up most of the giant otter's diet. They hunt alone or in groups, sometimes using coordinated efforts, and must be successful often to meet their daily.
At the time of Carter and Rosas' writing, vision had not been directly studied, but field observations show the animal primarily hunts by sight; above water, it is able to recognize observers at great distances. The fact that it is exclusively active during the day further suggests its eyesight should be strong, to aid in hunting and predator avoidance. In other otter species, vision is generally normal or slightly myopic , both on land and in water.
The giant otter's hearing is acute and its sense of smell is excellent. The giant otter is an especially noisy animal, with a complex repertoire of vocalizations. All otters produce vocalizations, but by frequency and volume, the giant otter may be the most vocal. Quick hah barks or explosive snorts suggest immediate interest and possible danger. A wavering scream may be used in bluff charges against intruders, while a low growl is used for aggressive warning.
Hums and coos are more reassuring within the group. Whistles may be used as advance warning of nonhostile intent between groups, although evidence is limited. Newborn pups squeak to elicit attention, while older young whine and wail when they begin to participate in group activities.
Sign up to our newsletter Get the latest wild news direct to your inbox. The incredible Giant Otter is of the rarest creatures that lives in Tambopata. At the time of Carter and Rosas' writing, vision had not been directly studied, but field observations show the animal primarily hunts by sight; above water, it is able to recognize observers at great distances. The animal is susceptible to a variety of diseases, including canine parvovirus. An Action Plan for their Conservation". Western mountain coati N.
The giant otter is a highly social animal and lives in extended family groups. Group sizes are anywhere from two to 20 members, but likely average between three and eight. Group members share roles, structured around the dominant breeding pair. The species is territorial, with groups marking their ranges with latrines , gland secretions, and vocalizations.
Aggression within the species "intraspecific" conflict has been documented. Defence against intruding animals appears to be cooperative: Researchers emphasize that even between groups, conflict avoidance is generally adopted. Group hierarchies are not rigid and the animals easily share roles. Giant otters build dens, which are holes dug into riverbanks, usually with multiple entrances and multiple chambers inside. They give birth within these dens during the dry season. They give birth between August and September, and the young pups emerge for the first time in October and November, which are the months of lowest water and fish concentrations in the dwindling lakes and channels are at their peak.
This makes it easier for the adults to catch enough fish for the growing young, and for the pups to learn how to catch fish. The entire group, including nonreproductive adults, which are usually older siblings to that year's pups, collaborates to catch enough fish for the young. Details of giant otter reproduction and life cycle are scarce, and captive animals have provided much of the information.
Females appear to give birth year round, although in the wild, births may peak during the dry season. The estrous cycle is 21 days, with females receptive to sexual advances between three and 10 days.
Mothers give birth to furred and blind cubs in an underground den near the river shore and fishing sites. The giant otter is very sensitive to human activity when rearing its young. No institution, for example, has successfully raised giant otter cubs unless parents were provided sufficient privacy measures; the stress caused by human visual and acoustic interference can lead to neglect, abuse and infanticide , as well as decreased lactation. In the wild, it has been suggested, although not systematically confirmed, that tourists cause similar stresses: All group members may aggressively charge intruders, including boats with humans in them.
The longest documented giant otter lifespan in the wild is eight years. In captivity, this may increase to 17, with an unconfirmed record of The animal is susceptible to a variety of diseases, including canine parvovirus. Parasites, such as the larvae of flies and a variety of intestinal worms, also afflict the giant otter. The giant otter is an apex predator , and its population status reflects the overall health of riverine ecosystems.
One full-year study of giant otter scats in Amazonian Brazil found fish present in all fecal samples. Fish remains were of medium-sized species that seem to prefer relatively shallow water, to the advantage of the probably visually oriented giant otter. Prey species found were also sedentary, generally swimming only short distances, which may aid the giant otter in predation.
Hunting in shallow water has also been found to be more rewarding, with water depth less than 0. The species can hunt singly, in pairs, and in groups, relying on sharp eyesight to locate prey. Prey chase is rapid and tumultuous, with lunges and twists through the shallows and few missed targets. The otter can attack from both above and below, swiveling at the last instant to clamp the prey in its jaws.
Giant otters catch their own food and consume it immediately; they grasp the fish firmly between the forepaws and begin eating noisily at the head. The species is amphibious, although primarily terrestrial. Other water habitats include freshwater springs and permanent freshwater lakes. The giant otter seems to choose clear, black waters with rocky or sandy bottoms over silty, saline, and white waters. Giant otters use areas beside rivers for building dens, campsites, and latrines. Giant otters adopt communal latrines beside campsites, and dig dens with a handful of entrances, typically under root systems or fallen trees.
One report found between three and eight campsites, clustered around feeding areas. In seasonally flooded areas, the giant otter may abandon campsites during the wet season, dispersing to flooded forests in search of prey. These can become quite extensive, including "backdoor" exits into forests and swamps, away from the water. Research generally takes place in the dry season and an understanding of the species' overall habitat use remains partial. An analysis of dry season range size for three otter groups in Ecuador found areas between 0. Utreras [60] presumed habitat requirements and availability would differ dramatically in the rainy season: Other researchers suggest approximately 7 square kilometres 2.
Adult giant otters living in family groups have no known serious natural predators , however there are some accounts of black caimans in Peru and yacare caimans in the Pantanal preying on giant otters.
When in the water, the giant otter faces danger from animals not strictly preying upon it: Even if without direct predation, the giant otter must still compete with other predators for food resources. Duplaix documented interaction with the neotropical otter. The smaller neotropical otter is far more shy, less noisy, and less social; at about a third the weight of the giant otter, it is more vulnerable to predation, hence, a lack of conspicuousness is to its advantage. The neotropical otter is active during twilight and darkness, reducing the likelihood of conflict with the diurnal giant otter.
Other species that prey upon similar food resources include the caimans and large fish that are themselves piscivores. Gymnotids , such as the electric eel, and the large silurid catfish are among aquatic competitors. Two river dolphins, the tucuxi and boto , might potentially compete with the giant otter, but different spatial use and dietary preferences suggest minimal overlap. The IUCN listed the giant otter as "endangered" in ; it had been considered " vulnerable " under all previous listings from when sufficient data had first become available. The animal faces a variety of critical threats.
Poaching has long been a problem. Statistics show between and Amazonian Brazil alone accounted for 1, to 3, pelts annually. The species was so thoroughly decimated, the number dropped to just 12 in The implementation of CITES in finally brought about significant hunting reductions, [13] although demand did not disappear entirely: The threat has been exacerbated by the otters' relative fearlessness and tendency to approach human beings.
They are extremely easy to hunt, being active through the day and highly inquisitive. Farmers follow, creating depleted soil and disrupted habitats. As human activity expands, giant otter home ranges become increasingly isolated. Subadults leaving in search of new territory find it impossible to set up family groups. Other threats to the giant otter include conflict with fishermen, who often view the species as a nuisance see below. Ecotourism also presents challenges: An IUCN study in suggested 1, to 5, otters remain.
In , most of this species lived in the Brazilian Amazon and its bordering areas. Suriname still has significant forest cover and an extensive system of protected areas, much of which protects the giant otter. Other countries have taken a lead in designating protected areas in South America. The park harbors many endangered plants and animals, including the giant otter, and holds the world record for mammal diversity.
Throughout its range, the giant otter interacts with indigenous groups , who often practice traditional hunting and fishing. A study of five indigenous communities in Colombia suggests native attitudes toward the animal are a threat: Even when told of the importance of the species to ecosystems and the danger of extinction, interviewees showed little interest in continuing to coexist with the species.
Schoolchildren, however, had a more positive impression of the animal. In Suriname, the giant otter is not a traditional prey species for human hunters, which affords some protection. Logging, hunting, and pup seizure may have led groups to be far more wary of human activity. Local people sometimes take pups for the exotic pet trade or as pets for themselves, but the animal rapidly grows to become unmanageable.
While revealing of the affection held for the animals, the seizure was a profound blow to the breeding pair, which went on to lose their territory to competitors. The species has also appeared in the folklore of the region. It plays an important role in the mythology of the Achuar people , where giant otters are seen as a form of the tsunki , or water spirits: They appear in a fish poisoning legend where they assist a man who has wasted his sexual energy, creating the anacondas of the world from his distressed and extended genitals.
Giant otters served as Yaku runa's canoes. From Wikipedia, the free encyclopedia. Giant otter [1] Giant otter Conservation status.
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Lists with This Book. This book is not yet featured on Listopia. In the 'Great Nor'-west' of Canada, a thousand miles away from civilization, a group of hardy British hunters and trappers brave the ice, snow, storms, rapids and bears in an unforgiving region with eight months of Winter.
With a colorful group of French-Canadians, Scottish Highlanders and a mischievous mixed-race scout called Salamander, they establish their camp, befriend and trade with the local tribes and have some adventures. Then Maxby falls for Waboose meaning 'rabbit' , the daughter of a native mother and an American father, now dead. Maxby's affections and a secret left to Waboose by his father change the young outdoorsman's priorities.
Ballantyne's descriptions of the awesome acts of Nature are superbly drawn and highly stirring, such as when the ice first breaks up over the water with the coming of spring, though he goes a little overboard with the exclamation points this time around. Despite the use of period terms such as 'redskins' and 'savages', the treatment of the Native Americans is about as respectful as you will find in a 19th century novel; more than once the narrator, a religious, asserts that all men are created equal. There are bad native characters, but there are bad fur-trappers too.
And of course Big Otter is the real hero of the book, though he is offstage often and is entirely stoic when present, a man of action and few words - frequently just one in fact. Rich rated it liked it Jun 13, Brendon rated it it was ok Nov 18, Kelsey added it Jul 25, Camp marked it as to-read May 07,