The giant otter or Amazon giant otter (Pteronura brasiliensis) is a mammal belonging to the Mustelidae family and the Pteronura genus. It is the only species within this genus and also the largest of the family It has various common names depending on the region where it is located, so it is known as ariraí (Argentina, Bolivia and Paraguay), ariranha (Brazil), tie wolf (Uruguay), river wolf (Peru and Bolivia), large river wolf (Argentina and Paraguay), water dog (Colombia, Venezuela and Guyana) and watradagoe (Suriname).
It has a great affinity for human beings, hence the origin of one of its common names, water dog. Due to its large size and skin type, it has been hunted for decades in a terrible and disproportionate way in order to be used in the fur industry. Currently, the factors that put the giant otter at risk have increased considerably, so its population is decreasing. On our site, we want to present you with various informative aspects about the giant otter, so that you can learn more about this curious animal.
Origin of the Giant Otter
Although with opposing positions, it was proposed that the giant otter has two subspecies: Pteronura brasiliensis brasiliensis and Pteronura brasiliensis paranensis. The first would be located in Suriname, the Guianas, southern Venezuela, southern Colombia, eastern Ecuador, eastern Peru, Bolivia, Paraguay and Brazil; while the second, in the Paraguay and Paraná rivers in Brazil, northern Argentina and Uruguay. Subsequently, the subspecies P. b. paranensis as a synonym of a different subspecies, P. b. paraguensis.
Subsequent genetic studies support the subdivision of this species into four different evolutionary units, which are located at:
- The Madre de Dios River with the Madeira River.
- The Pantanal.
- The Amazon with the Orinoco and Guianas drainages.
- The Itenez - Guapore Basin.
The aspect that is not in dispute is that the giant otter lives exclusively in South America and its populations vary proportionally depending on the region, however, have disappeared from some areas. The possibility that the giant otter is related to an Asian otter (Lutrogale perspicillata) has been documented, with which it bears a certain morphological and behavioral relationship.
Characteristics of the giant otter
When it is an adult it can measure 2 meters, weighing up to 30 kilos Its coloration is intense brown, with the presence of creamy white spots, in the lower area of the neck; curiously, the shape of this patch is unique to each individual, which makes it easy to identify for research purposes. Its legs are large and webbed, but the front ones are shorter than the rear ones, although all of them are adapted for swimming; as well as its robust and flat tail, which greatly facilitates its movements under water. They have five toes on each foot, with strong non-retractable claws, which are extremely useful for catching and tearing apart the prey they devour. In addition, they have membranes that reach the tip of each finger.
The giant otter has well-developed muscles and jaws, and has between 34 and 36 teethBoth the ears and nostrils are small, with the ability to close them with the use of focused muscles when underwater. The snout is short and wide, the nasal pad is completely covered with hair, and it also has whiskers that are highly sensitive and allow them to perceive their prey underwater.
The fur is extremely dense, so much so that the skin does not get wet when submerged in water because of the barrier formed by its hairs. Males are usually larger and heavier than females.
Giant Otter Habitat
The giant otter occupies a wide variety of freshwater bodies and is not used to living in s alt water. Inhabits slow-flowing rivers and streams, ponds, swampy or rocky areas, swampy forests, and flooded forests; On the other hand, it avoids very large and deep water flows, as well as those close to the Andes. The availability of food is a decisive aspect for the presence of the species in the mentioned ecosystems.
These animals require dense vegetation around bodies of water to build their burrows. During the dry season they remain grouped in the watercourses and disperse in the rainy season through the wooded areas that are flooded. They can eventually be seen in canals associated with agricultural land. When they inhabit areas such as lakes, they can maintain a not so large range for their distribution, while in the case of fluvial courses, they show wider variations in terms of their expansion.
Giant Otter Customs
These animals define well-established territories and form family groups that range between 2 and 15 individuals, forming stable and dominant pairs, young individuals non-breeders and offspring. It is also common for sexually mature individuals to pass through the established areas. Eventually, a family may accept a young person from another family group. They are of diurnal habits, somewhat clumsy when moving on land, but quite agile underwater.
They have a life expectancy of 8 years when they live in the wild, while in captivity they have lived up to 10 years. Some studies have reported that they seek rocky or sandy bottoms rich in s alts to rest. A peculiar feature of this species is the provision of a specific place where the family group defecates, which is why it is established that the giant otter makes latrines
They usually prepare large spaces of up to 28 meters for their dens, in which they dig or create various entrances under the vegetation that makes them up. Interestingly, the burrows must be in higher areas to keep them dry and prevent them from flooding. They also tend to mark the boundaries with their urine to keep other animals away. On the other hand, they have a complex system of communication through sounds, which emit various types of messages; In addition to this, also being a fairly trusting species, it does not usually go unnoticed in the places it inhabits.
Giant Otter Feeding
The giant otter is a voracious and almost insatiable carnivore, its prey very difficult to escape when they are chased. In addition, an adult individual is capable of consuming up to 4 kilos of food a day Fish constitute their main source of food, especially those belonging to the families Pimelodidae, Serrasalmidae, Curimatidae, Erythrinidae, Characidae, Anostomidae, Cichlidae and Loricariidae. However, it can also feed on:
- Crabs.
- Small mammals.
- Birds.
- Alligators.
- Snakes.
- Mollusks.
These animals have various hunting strategies and can do so alone, in pairs or groups. They usually make quick and sudden movements, turning around in the water. They have a sharp vision under this medium, which helps them to identify the food, which with the support of their claws they easily capture. When the giant otter hunts in groups, it is capable of capturing large individuals, such as alligators or anacondas, individuals that are also quite strong. Also a quite peculiar feature is that this species has been observed associated with the pink river dolphin (Inia geoffrensis) to jointly capture fish.
Giant otter reproduction
Although at two and a half years they have already reached sexual maturity, they reproduce on average at almost five years of age. After courtship, the reproductive act occurs in the water and the gestation period lasts between 64 to 77 days. In addition, each pair usually has one litter a year and very occasionally they can have two, which are from 1 to 6 pups, but on average there are two. At birth, the cubs are blind and depend on maternal care, at least until the fourth week, when they can begin to open their eyes. At two months they begin to swim, and at three they begin their first attempts to hunt, mainly fish. Adults play a critical role in teaching their children to hunt. Weaning offspring can occur as early as nine months after birth.
These otters establish quite close family ties In fact, the youngest can stay with their family until they reach sexual maturity. The males and brothers have an active participation in the care and teaching of the young. Once a new litter is born, the parents decrease interest in the young and focus on the newborns.
Giant Otter Conservation Status
Initially the main threat factor for the species was hunting in order to obtain its skin and market it to the fur industry, However, over time, another series of aspects have emerged that put the giant otter at risk, such as the destruction of the habitat associated with the bodies of water, overfishing, the contamination of rivers by mining and the use of agrochemicals such as fertilizers and pesticides. Mining is a highly disturbing action of the ecosystem of the giant otter, which in addition to contaminating and destroying ecosystems, contributes to the sedimentation of these fluvial bodies, which occurs mainly in the Guiana Shield region (Suriname, Guyana, French Guiana)., southern Venezuela and northern Brazil) and also in southeastern Peru. Additionally, the construction of dams and the alterations of watercourses are also important causes for the affectation of these animals.
The giant otter is included in Appendix I of the Convention on International Trade in Endangered Species (CITES) and is listed as an endangered species of extinction by the International Union for Conservation of Nature. Despite the proposal of various actions, such as the protection of its habitat, mining continues to cause alarming damage in the aforementioned areas.
The giant otter is an animal that has practically no natural predators within the ecosystems it inhabits, however, human beings are its main and most dramatic threat, perhaps not so much because of direct hunting, but because of the important alteration of its habitat.
