The neotropical otter or neotropical river otter, scientific name Lontra longicaudis is an otter species present in Middle America, South America, and the island of Trinidad. It is bodily just like the northern and southern river otter, which happen immediately north and south of this species’ range.
Neotropical Otter profile
The size of the neotropical otter can range from 36–66 centimeters (14–26 in), plus a tail of 37–84 centimeters (15–33 in). Bodyweight ranges from 5–15 kilograms (11–33 lb). Otters are members of the family Mustelidae, essentially the most species-rich (and subsequently various) family within the order Carnivora.
This otter is present in many various riverine habitats, together with deciduous and evergreen forests, savannas, llanos, and Pantanal. It prefers to dwell in clear fast-flowing rivers and streams. It is a comparatively solitary animal and feeds totally on fish and crustaceans.
Lontra longicaudis is present from Northwestern Mexico, south into South America; it’s the commonest otter in Mexico and has the widest distribution of the three S. American Lontra species.
Neotropical Otter Physical Description
The neotropical otter is roofed in a brief, darkish grayish-brown pelage. Fur shade is lighter across the muzzle and throat. They possess a long vast tail, with brief stout legs and totally webbed toes. Sexually dimorphic, the males are about 25% bigger than the females.
The body mass of the otter typically ranges from 5 to 15 kilograms. Neotropical otters will talk with close-by otters through scent marking. Communication may additionally happen through whistles, hums, and screeches.
Lontra longicauda typically weighs lower than 12 kilograms. Sexually dimorphic in size, the males average 20-25% bigger than the females.
L. longicauda is also referred to as the Neotropical otter. Head and body size maybe 360-660 mm, size of the tail 370-840 mm, size of the hindfoot 94-144 mm, and size of the ear ranges from 18-22 mm.
Some average measurements of the long, flat skull embody basal size about 96.four mm, zygomatic breadth 68.1mm, and postorbital breadth averaging 17.9 mm. The head is small and flat, bearing small eyes and brief, round ears. The otter’s neck is thicker than the pinnacle.
The Neotropical otter has a brief, dense, modern pelage, which is described as a lustrous grayish-brown. This otter is barely paler ventrally, particularly on the throat. On its face, the higher lip, mandible, and tip of the muzzle are silvery-white to yellowish.
The muzzle seems broad. The tail is long, vast, and fairly thick on the base. It tapers to some extent. The legs are brief and stout, and the toes on all of the otter’s feet are webbed.
Females have 4 nipples on the stomach. The males have a well-developed baculum with a total size of around 72 mm. It has a small ventral groove, shallow on the proximal end and working deeper on the distal end
The dental system seldom varies from that of Eurasian otters, besides within the few instances of otters that have dental anomalies. Females and males have identical systems. The dental system (for half the skull) is as follows:
Upper: 3 incisors, 1 canine, 4 premolars and 1 molar
Lower: 3 incisors, 1 canine, 3 premolars, and a couple of molars
The neotropical otter has the widest distribution of all of the lontra species. Their habitat can range from northwest Mexico to central Argentina.
Neotropical Otter Habitat
Lontra longicaudis typically shelters in a self-excavated burrow close to everlasting lakes or streams. They rely upon a water setting with loads of riparian vegetation.
There have been a number of various kinds of shelters frequented by the otters. These shelter varieties embody: a cavity amongst stones, cavity underneath tree roots, limestone dissolution cavity, a cavity in a rocky wall, house amongst vegetation, and excavated burrows.
The commonest sort of shelter utilized by the otters on this examination was the cavities amongst stones (35.2%). This sort of shelter is just not deep and has a broad entrance. It is definitely an area amongst pebbles and rock alongside the river bank.
The Neotropical river otter can also be recognized to make use of caves as shelters, which different otters have a tendency to not do. A number of caves have been used to rear younger.
It was advised the caves have been typically removed from the primary river and have been protected sites. These are options widespread to different otter rearing dens.
It was additionally famous that otters’ scent-marking behavior is concentrated in these areas of the house ranges which they frequent more than others, of their exercise facilities.
Along the Betari River, Lontra longicaudis didn’t focus its scent marks around shelters. Apparently, this implies the shelters are usually not essentially facilities of exercise for the otters in riverine habitats.
They choose clear and fast-flowing rivers and are hardly ever recognized to settle within the sluggish, silt-laden lowland rivers. While largely occurring at 300 to 1500 m above sea level they’ve been discovered settled at 3000 m.
They require plentiful riparian vegetation and plentiful den sites, however, apart from that, the neotropical otter may be very versatile and tolerant to environmental change.
The otter will choose sites that are stable, high, dry, and in proximity to deep water. The Neotropical otter is the best generalist of all otter species. It can inhabit formidable habitats comparable to wastewater remedy crops, rice and sugar cane plantations, drainage ditches, and swamps.
It can inhabit chilly, glacial lakes within the Andes of Ecuador. It also can dwell on the shorelines of marine environments looking at marine species and taking part in within the extremely saline water.
Neotropical Otter Behavior
The neotropical otter is a solitary animal. A male will solely stick with the feminine for at some point within the breeding season. Females have total care of the younger.
One approach these otters talk about is scent marking. They deposit feces in conspicuous areas comparable to logs, root methods, rocks, sand bars, and planks underneath bridges.
It is usually recommended they like sites that are stable, high, dry, and close to deep water, however they’ll spraint on steadily flooded surfaces if the previous is just not obtainable. It is believed that painting could perform for commercial and for the coordination of sexual exercise.
Communication also can happen when the otter emits quite a lot of whistles, hums, and screeches. Otters approaching observers in Argentina uttered a loud “hahh” which researchers felt was an alarm call.
No information was discovered relating to playing behavior, how a lot of time this species spends within the water, or the way it spends the day apart from foraging. These animals have the shape, fur and buoyancy wanted to spend a great deal of time within the water.
They transfer with a humping gallop holding their head and tail low, the back humped high (Lariviere 1999). Given their selection of shelters so near the water it may be anticipated the Neotropical river otter spends not less than a part of the day swimming and taking part in as different otters do.
Neotropical Otter Food Habits
The neotropical otter feeds primarily on fish, crustaceans, and mollusks. It is also an opportunistic feeder, consuming bugs, reptiles, birds, and small mammals.
It has been advised that foraging happens all day, taking place more generally within the center or late afternoon. Nocturnal exercise is uncommon, however, some neotropical otters have grown to be fully nocturnal when their regular activities are disturbed by people.
L.longicaudis is a swish swimmer and diver. They are at all times present in or close to the water. Their foraging dives can final from 20-30 seconds. The otter consumes small prey whereas within the water however will take bigger prey to the shore to eat it.
Two separate research have been conducted relating to the feeding habits of the neotropical river otter and the outcomes are described right here. One examination was carried out at a dam within the “Duas Bocas” Biological Reserve in Brazil, between July 1986 to July 1987.
This reserve is roofed primarily by the Atlantic Rain Forest. The examination was based mostly on otter fecal (spraints) analysis and in contrast with recognized species discovered within the dam.
The materials collected were immune to gastric juice, together with fish bones, rays, jaws, and teeth of a lot of animals, plus crab and bug exoskeletons.
The most necessary meal merchandise was fish, which on this examination was present in 97.2% of the samples. Also noticed have been crustaceans, amphibians, mammals, bugs, and birds.
Crustaceans have been the second most encountered meals merchandise. The authors indicated that better abundance and simpler seize of fish make them the primary meal merchandise for the otters.
Between August 1993 and September 1994 one other examination was carried out in an Atlantic forest stream in south-eastern Brazil, the Betari River. Likewise, the creator studied undigested stays within the otter’s scat.
In 93% of the samples, fish was discovered. Aquatic bugs and crustaceans have been additionally discovered steadily (78.9%). The conclusion of this examination was that otters are generally influenced by their collection of meal objects in response to the supply of prey and its means to flee.
Neotropical Otter Diet
The neotropical otter’s diet consists largely of fish and crustaceans making up 67% and 28%, respectively, of its total diet. The otter can even sometimes feed on mollusks and small mammals.
This otter is understood to sometimes assault fishnets for a source of prey, hindering fishing productiveness. Otter’s dwelling close to marine habitats can have a lot higher proportion of crustaceans of their diets.
Seasonality additionally tremendously has an effect on otters’ meal selection. During the dry season, when much fewer fish and crustaceans can be found, one examination discovered a higher proportion of frogs in otters’ diet. Though, throughout this time, anurans and reptiles nonetheless made up a really small share of the total diet.
This may additionally be on account of the truth that sure frogs mate in the course of the dry season, so the frogs are simpler prey. All in all, the distribution of accessible meals species in a specific space roughly correlates to the share of every species present in otters’ diet.
Neotropical Otter Reproduction
Breeding happens largely in spring. Gestation will final 56 days and produce a litter of 1–5 pups. The pups are born blind but totally furred. They will emerge from their mom’s nest when about 52 days and start swimming at 74 days.
They are raised fully by their mom, as males don’t present any parental care. The male will solely spend a single day with the feminine throughout the breeding season.
The feminine should hold her pups protected from predation by different neotropical otters. In one captive breeding state of affairs, cannibalism by the mom could have occurred, although it was not confirmed.
In an ecologically wholesome space, there are numerous possible shelters so a person can select its most well-liked den. However, research present that not all possible shelters are occupied, and never all shelters are equally utilized by Neotropical otters.
Otters go to totally different shelters with various frequencies, from as soon as or few occasions per as many as many occasions per year.
One issue that influences their choice for a den has to do with the water level, particularly throughout flood season, when a den close to the water level can simply be washed away. A den could also be on the water level, close to the bank, or more than 1.5 meters in regards to the water level.
Depending on the otters’ locality, it breeds largely within the spring, however may additionally breed all through the year. Following a gestation interval of 56 days, one to 5 younger are born, however, typically, there’s solely two or three within the litter. There is a sign of facultative delayed implantation, however, it isn’t recognized how long the delay could also be.
Young are born blind, opening their eyes after 44 days. They are born totally furred. The younger leave the den or nest when about 52 days old and spend a lot of the day taking part close to the natal den. At about 74 days publish start they start their aquatic exercise with their moms. Males don’t present any parental care.
There are many different components influencing otters’ preferences for a shelter. Neotropical otters choose dens close to contemporary water, high meal availability, and comparatively deep and vast water.
During seasons with low water, particular person otters could also be more clumped as a result of they’ll all transfer into areas of a river with deeper water, with more fish.
Deep, vast swimming pools have been discovered to have a better variety of fish, preferential for otters. Some research present that otters will forgo a much less preferable, however more obtainable den, like a muddy riverbank, to spend more time in a preferential den, like a rocky shore.
Neotropical otter females will rear pups in a den with no male. In some instances, a feminine could discover a den that has the house to maintain her pups and a separate space for her personal house.
An examination of a male otter’s motion over 35 days confirmed he used three totally different dens without communication between them.
Also, this particular person moved between two islands separated by a one-kilometer vast estuary. He spent a while in a site with heavy mud, a poor substrate for a den, so he could have been on the transfer to seek out meals.
Dens could have more than one opening, so the otter can simply exit to forage for meals whereas staying protected from predators. There are many classifications of dens that Neotropical otters could use.
A cavity amongst stones or underneath tree roots is most well-liked. Insure components of South America, an otter could come throughout a limestone dissolution cavity or a cavity in a rocky wall.
Though missing a source of light, the Neotropical otter could make great use of this sturdy house. As a final resort, an otter expends energy to excavate an area amongst vegetation or a riverbank, although these properties are much less sturdy.
Vegetative cover can also be essential for the Neotropical otter. In comparability to different otter dens, the Neotropical otter dens should not have holes immediately into the water, they don’t use plant materials as bedding, and can dwell in caves without light.
They are elusive creatures and like undisturbed forests without indicators of human exercise. When people clear forests for agricultural land, the variety of obtainable otter habitats plummets.
Like different otter species, neotropical otters will mark their territory with scratching or spraint (feces) in apparent locations like rocks and underneath bridges.
Signs of marking could also be most concentrated around their dens. They are inclined to solely mark in sure areas of the den, separate from the exercise heart of the den. In caves, the place water sources could leak by way of the partitions and wash away the scent, the resident could mark areas inside their den.
The niches and ranges of the Giant river otter and the Neotropical otter overlap broadly. Both species are diurnal and primarily piscivorous.
The Giant otter is much less of a generalist in habitat, preferring slow-moving water and overhanging vegetation, however the place the Neotropical otter may additionally happen. The Giant otter is way bigger and hunts in teams, so it could possibly take bigger prey.
Some areas, just like the Pantanal, have high sufficient productiveness, so each otter species can exist with little or no competitors. Additionally, Neotropical otters choose deeper and wider streams than Giant otters.
Neotropical Otter Conservation
The neotropical otter is listed as Near Threatened by the IUCN. The species is at present protected in Argentina and lots of different South American international locations.
Heavy trying to find its fur within the 1950s–1970s resulted in a lot of native extinction over the otter’s range. Illegal looking, habitat destruction by way of mining and ranching, and water air pollution nonetheless have an effect on the inhabitants of the neotropical otter.
Although there have been making an attempt at captive breeding, they’re largely unsuccessful.
Most unfavorable emotions about otters come up from fishermen who compete with the otter for fish. More information is required to find out how a lot of overlap exists between the fishermen’s desired catch and the otter’s diet.
The highest competitors between Neotropical otters and fishermen happen throughout drought situations. Fishermen could transfer out of their regular fishing areas, into deeper swimming pools the place the otter normally hunts within the absence of people.
Otters are hardly ever victims of being caught in gillnets, themselves, and really hardly ever die from the identical trigger.
Neotropical otters are threatened by habitat degradation related to agriculture, soil compaction, air pollution, roadways, and runoff. Also, when forests are cleared for cattle grazing, heavy vegetation (which is the otter’s most well-liked habitat) close to streams can also be cleared or trampled by cattle.
This species is an important ecological indicator as a result of they like ecologically wealthy, aquatic habitats and have a low reproductive potential.
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