Neotropical otter (Lontra longicaudis)

May 26, 2019 Interesting Creatures in Guyana, News

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The neotropical otter or neotropical river otter (Lontra longicaudis) is an otter species found in Central America, South America and the island of Trinidad. It is physically similar to the northern and southern river otter, which occur directly north and south of this species’ range.
The length of the neotropical otter can range from 90 –150 centimetres (35–59 in), of which the tail comprises about a third. Body weight ranges from 5–15 kilograms (11 –33 lb). Otters are members of the family Mustelidae, the most species-rich (and therefore diverse) family in the order Carnivora.
This otter is found in many different riverine habitats, including deciduous and evergreen forests, savannas, llanos and pantanal. It prefers to live in clear fast-flowing rivers and streams. It is a relatively solitary animal and feeds mostly on fish and crustaceans.
The neotropical otter is covered in a short, dark greyish-brown pelage. Fur colour is lighter around the muzzle and throat. They possess a long wide tail, with short stout legs and fully webbed toes. Sexually dimorphic, the males are about 25% larger than the females.
Body mass of the otter generally ranges from 5 to 15 kilograms. Neotropical otters will communicate with nearby otters via scent marking. Communication may also occur via whistles, hums, and screeches.
This otter prefers clear and fast-flowing rivers and is rarely known to settle in the sluggish, silt-laden lowland rivers. While mostly occurring at 300 to 1500 m above sea level they have been found settled at 3000 m. They require abundant riparian vegetation and abundant den sites, but other than that the neotropical otter is very versatile and tolerant to environmental change.
Breeding occurs mostly in spring. Gestation will last 56 days and produce a litter of 1–5 pups. The pups are born blind yet fully furred. They will emerge from their mother’s nest when about 52 days and begin swimming at 74 days. They are raised completely by their mother, as males do not provide any parental care. The male will only spend a single day with the female during breeding season. The female must keep her pups safe from predation by other neotropical otters. In one captive breeding situation, cannibalism by the mother may have occurred, though it was not confirmed.
Females will rear pups in a den without a male. In some cases, a female may find a den that has space to keep her pups and a separate area for her own space.
A study of a male otter’s movement over 35 days showed he used three different dens without communication between them. Also, this individual moved between two islands separated by a one-kilometre-wide estuary. He spent some time in a site with heavy mud, poor substrate for a den, so he may have been on the move to find food.
Like other otter species, neotropical otters will mark their territory with scratching or spraint (faeces) in obvious places like rocks and under bridges. Signs of marking may be most concentrated around their dens. They tend to only mark in certain areas of the den, separate from the activity centre of the den. In caves, where a water sources may leak through the walls and wash away the scent, the resident may mark areas inside their den.
The niches and ranges of the Giant river otter and the Neotropical otter overlap widely. Both species are diurnal and mainly piscivorous.
The Giant otter is less of a generalist in habitat, preferring slow-moving water and overhanging vegetation, but where the Neotropical otter may also occur. It is much larger and hunts in groups, so it can take larger prey. Some areas, like the Pantanal, have high enough productivity, so both otter species can exists with little or no competition. Additionally, Neotropical otters prefer deeper and wider streams than Giant otters.
The neotropical otter is listed as Near Threatened by the IUCN. The species is currently protected in Argentina and many other South American countries. Heavy hunting for its fur in the 1950s–1970s resulted in much local extinction over the otter’s range. Illegal hunting, habitat destruction through mining and ranching, and water pollution still affect the population of the neotropical otter. Although there have been attempts at captive breeding, they are largely unsuccessful.
Most negative feelings about otters arise from fishermen who compete with the otter for fish. More data is needed to determine how much overlap exists between the fishermen’s desired catch and the otter’s diet.
The highest competition between Neotropical otters and fishermen occurs during drought conditions. Fishermen may move out of their regular fishing areas, into deeper pools where the otter usually hunts in the absence of people.
In a study on local fishermen’s attitudes, the study revealed that fishermen’s knowledge aligned with scientific data about the Neotropical otter’s behavior, body description, and other data. Because the fishermen’s facts aligned with scientific knowledge, scientists could then trust the fishermen’s first-hand accounts about problems they experience with otters.
Fishermen reported that otters will damage their fishing gear, but do not damage crab and shrimp nets. The locals have varying opinions about the otters’ presence, from understanding they have to share space with the otters to wanting to kill the otters.
Fishermen’s knowledge and frequent contact with this elusive species might qualify them as the best managers of the species. There have been proposals to subsidize their fish profits lost to otters. However, it might be more beneficial to pay them to collect data on the species. This would benefit fishermen economically, improve fishermen’s attitude toward the animal, and build on currently insufficient data about this species.
Otters are rarely victims of gillnets and very rarely die from the same cause.
Neotropical otters are threatened by habitat degradation associated with: agriculture, soil compaction, pollution, roadways, and runoff. Also, when forests are cleared for cattle grazing, heavy vegetation (which is the otter’s preferred habitat) near streams is also cleared or trampled by cattle. This species is a very important ecological indicator because they prefer ecologically rich, aquatic habitats and have a low reproductive potential. [Source: Wikipedia]

 

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