THE RED RUFFED LEMUR

 

The red ruffed lemur (Varecia rubra) is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur (Varecia variegata). Like all lemurs, it is native to Madagascar. It occurs only in the rainforests of Masoala, in the northeast of the island.^[1] It is one of the largest primates of Madagascar with a body length of 53 cm, a tail length of 60 cm and a weight of 3.3–3.6 kg. Its soft, thick fur is red and black in color and sports a buff or cream colored spot at the nape, but a few are known to have a white or pink patch on the back of the limbs or digits and a ring on the base of the tail in a similar color.

 

 Physical characteristics

Red ruffed lemur in detail

Ruffed lemurs are the largest members of the family Lemuridae,^[4] with this species being the larger of the two. They weigh 3.3–3.6 kg (7.3–7.9 lb).^[5] They are about 53 cm (21 in) long, with a 60 cm (24 in) tail.^[6] Females are slightly larger than males.^[7] They have slender bodies and long legs. Red ruffed lemurs have a narrow snout with small back ears that are sometimes hidden by their long fur. They groom themselves using their toothcomb.^{[citation needed]}

As their name would suggest, they have a rust-coloured ruff and body. Their heads, stomachs, tails, feet, and the insides of their legs are black. They have a white patch on the back of their neck, and may also have white markings on their feet or mouth.^[7]

 

 

 Behavior

Red ruffed lemurs grooming each other

The red ruffed lemur is a very clean animal and spends a lot of time grooming itself and in social grooming. The lower incisors (front teeth) and the claw on the second toe of the hind foot are specially adapted for this behavior. The lower incisors grow forward in line with each other and are slightly spaced. This creates a toothcomb which can be used to groom its long, soft fur. The claw is also used for grooming.

The red ruffed lemur lives 15–20 years in the wild. In captivity, 25 years is not uncommon, and one lived to be about 33 years old. It is a diurnal animal, and most active in the morning and evening.^[8]

 

Social systems

A pair of red ruffed lemurs drinking

This primate typically lives in small, matriarchal groups of 2–16 individuals, but group sizes of up to 32 have been recorded. Its diet consists primarily of fruit, nectar, and pollen. Leaves and seeds may be eaten when fruit becomes scarce.^[6] Red ruffed lemurs will sometimes form large groups during the wet season when food is plentiful. They will all find one food source and forage together as a group. During the dry season they will often separate and find food on their own when fruits are scarce . This is unusual behavior as most other diurnal lemurs will stay together and forage in large groups even during the dry season.^[6] Field studies suggest that red ruffed lemurs, like black-and-white ruffed lemurs, may be found in monogamous pairs or in small, organized groups. Individuals out in the forest communicate through loud booming calls, which can be heard over considerable distances.^[9]

 

Breeding and reproduction

 

 Red ruffed lemurs reach sexual maturity at about two years of age, and start reproducing at about three years of age.^[4] Unlike all other diurnal primates,^[6] females keep their infants in nests 10–20 m (33–66 ft) above the forest floor, made with twigs, leaves, vines, and fur. Like all lemurs, and many Madagascan mammals, it has a fixed breeding season which takes place towards the end of the dry season (May to July). This is so the young can be born in the wet season when more food is available. Ruffed lemurs are also the only primates with litters of young, and, after a gestation period of 102 days, the female may give birth to up to six, although two or three is more typical. Newborns have fur and can see, but as they cannot move, the female leaves them in the nest until they are seven weeks old. Females can nurse up to six infants at the same time. Infant red ruffed lemurs are not as well developed at birth as other lemurs. This is not surprising because red ruffed lemurs have extremely short gestation periods. At birth, infants are not able to hold onto the mother. When she moves the infants she picks them up one by one. Mothers usually move their infants away from the nest after a week or two. When she forages she leaves her infants in a nearby tree. In the few days after she gives birth, if the mother needs to leave the nest, the father will stand guard.^[10] Weaning occurs at four months.^[7] It is estimated that 65% of young do not reach three months of age, and often die by falling from the trees.^[6]

 

Diet

 

The red ruffed lemur is mainly a fruit-eater, though it is known to eat leaves and shoots. They especially like figs.^[11]

 

Communication

 

 

The Duke Lemur Center has recorded about twelve different calls. The red ruffed lemur and Black-and-White Ruffed Lemur understand each other's calls, despite living in different parts of Madagascar. Scent marking is also an important means of communication.^[6]

 

 Conservation status

 

 The IUCN Red List states that the red ruffed lemur is critically endangered. Logging, burning of habitat, cyclones, mining, hunting, and the illegal pet trade are primary threats. They also have natural predators such as large snakes, eagles, and the fossa.^[1][12] The creation of the Masoala National Park in 1997 has helped protect this species, but many red ruffed lemurs do not live within the park's boundaries, and are still at high risk.^[6]

Recent studies show that they are critically endangered with a declining wild population. Illegal logging has increased since 2009, which has reduced the available forest habitat.^[1] Illegal logging for valuable tropic hardwoods, such as rosewood, is a particular threat, and linked to political instability.^[13] The captive population of red ruffed lemurs stands at 590 animals. The population of red ruffed lemurs is directed by a Species Survival Plan.^[13] Several of these zoos work with each other in breeding and caring for the captive population. To prevent inbreeding, wild caught animals have been introduced to the captive breeding program.

 

 

 

 

 

 

 Distribution of V. rubra^[1]

 

THE SPOTTED - NECKED OTTER

 

The spotted-necked otter (Hydrictis maculicollis), or speckle-throated otter, is an otter native to sub-Saharan Africa.

The spotted-necked otter is usually chocolate to reddish brown and marked with creamy or white blotches over the chest and throat. The head is broad with a short muzzle, small rounded ears, and a hairless nose pad. The teeth are adapted for consuming fish, with large sharp upper canine teeth, curved lower canines, and sharp carnassial teeth. The jaws are similarly adapted, with the mandibular fossa fitting so snugly into the condyle on the lower jaw that the latter cannot move sideways, making it easier to capture and hold fish. It is a relatively small species, with males measuring 71 to 76 cm (28 to 30 in) from nose to rump, and weighing 5.7 to 6.5 kg (13 to 14 lb), while females are 57 to 61 cm (22 to 24 in) and 3.0 to 4.7 kg (6.6 to 10.4 lb). The tail is long and muscular, measuring 39 to 44 cm (15 to 17 in) in both sexes. It is sleek and has webbed paws. Females have two pairs of teats, and while males have a large scrotum, the penis is hidden beneath the skin, to reduce drag while swimming.^[3]

 

 

Up to five subspecies have previously been identified, these most likely represent a natural variation in appearance between individuals, and no subspecies are currently recognised.^[3]

The spotted-necked otter inhabits lakes and larger rivers throughout much of Africa south of 10°N. It is common in Lake Victoria and across Zambia, but is absent in the Zambezi below Victoria Falls, Zambia.^[4] It does not venture into salt water.^[3]

The spotted-necked otter is very vocal, uttering high, thin whistles and rapid, shrill chatters.^[5] It sometimes lives in family groups, but appears to be social only under certain conditions. Males and females are separated for at least part of the year.^[4] They normally hunt alone, except when mothers are training their young, and are not territorial, sheltering through the night in short burrows, rock crevices, or patches of dense vegetation. On land, they travel mainly over regular paths, and rarely move more than 10 m (33 ft) from river or lake banks.^[3] Both mark these paths by "sprainting" sites, in which they habitually defecate and urinate.^[6]

 

 

The spotted-necked otter is diurnal and appears to hunt entirely by sight using short dives of less than 20 seconds each in clear water with good visibility.^[3] It carries larger prey ashore, but eats smaller prey while treading water.^[6] It primarily eats fish, typically less than 20 cm (7.9 in) in length, but also frogs and small crustaceans, especially when fish is in short supply.^[6]

 

 The female bears a litter of up to three young after a gestation period around two months. The young are born blind and helpless, and the mother cares for them for almost a year.^[5][3]

Known predators of the spotted-necked otter include lions, crocodiles and African fish eagles.^[3]

The spotted-necked otter is in decline, mostly due to habitat destruction and pollution of its clear-water habitats. It is hunted as bushmeat.^[2]

 

 

 

 

 

 

 

 

 Distribution of spotted-necked otter

 

 

 

 

 

 

 

 

 

 

 

THE SNAPPING TURTTLE AND TURTTLES

 

The common snapping turtle (Chelydra serpentina) is a species of large freshwater turtle in the family Chelydridae. Its natural range extends from southeastern Canada, southwest to the edge of the Rocky Mountains, as far east as Nova Scotia and Florida. The three species of Chelydra and the larger alligator snapping turtles (genus Macrochelys) are the only extant chelydrids, a family now restricted to the Americas. The common snapping turtle, as its name implies, is the most widespread.^[2]

The common snapping turtle is noted for its combative disposition when out of the water with its powerful beak-like jaws, and highly mobile head and neck (hence the specific epithet serpentina, meaning "snake-like"). In water, it is likely to flee and hide underwater in sediment. The common snapping turtle has a life-history strategy characterized by high and variable mortality of embryos and hatchlings, delayed sexual maturity, extended adult longevity, and iteroparity (repeated reproductive events) with low reproductive success per reproductive event.^[3]

Females, and presumably also males, in more northern populations mature later (at 15–20 years) and at a larger size than in more southern populations (about 12 years). Lifespan in the wild is poorly known, but long-term mark-recapture data from Algonquin Park in Ontario, Canada, suggest a maximum age over 100 years.^[3]

 

Anatomy and morphology

Close-up in Taum Sauk Mountain State Park

Head

 

 

C. serpentina has a rugged, muscular build with a ridged carapace (upper shell), although ridges tend to be more pronounced in younger individuals. The carapace length in adulthood may be nearly 50 cm (20 in), though 25–47 cm (9.8–18.5 in) is more common.^[4] C. serpentina usually weighs 4.5–16 kg (9.9–35.3 lb). Per one study, breeding common snapping turtles were found to average 28.5 cm (11.2 in) in carapace length, 22.5 cm (8.9 in) in plastron length and weigh about 6 kg (13 lb).^[5]

Males are larger than females, with almost all weighing in excess of 10 kg (22 lb) being male and quite old, as the species continues to grow throughout life.^[6] Any specimen above the aforementioned weights is exceptional, but the heaviest wild specimen caught reportedly weighed 34 kg (75 lb). Snapping turtles kept in captivity can be quite overweight due to overfeeding and have weighed as much as 39 kg (86 lb). In the northern part of its range, the common snapping turtle is often the heaviest native freshwater turtle.^[7]

Hatchlings emerging from the ground

 

Ecology and life history

 

 Common habitats are shallow ponds or streams. Some may inhabit brackish environments, such as estuaries. Common snapping turtles sometimes bask—though rarely observed—by floating on the surface with only their carapaces exposed, though in the northern parts of their range, they also readily bask on fallen logs in early spring. In shallow waters, common snapping turtles may lie beneath a muddy bottom with only their heads exposed, stretching their long necks to the surface for an occasional breath. Their nostrils are positioned on the very tip of the snout, effectively functioning as snorkels.^[8]

 

 

Snapping turtles consume both plant and animal matter, and are important aquatic scavengers, but they are also active hunters that prey on anything they can swallow, including many invertebrates, fish, frogs, reptiles (including snakes and smaller turtles), unwary birds, and small mammals. In some areas adult snapping turtles can be incidentally detrimental to breeding waterfowl, as they will occasionally take ducklings and goslings, but their effect on such prey is frequently exaggerated.^[8] As omnivorous scavengers though, they will also feed on carrion and a surprisingly large amount of aquatic vegetation.^[9]

Eggs

Common snapping turtles have few predators when older, but eggs are subject to predation by crows, American mink, skunks, foxes, and raccoons. As hatchlings and juveniles, most of the same predators will attack them as well as herons (mostly great blue herons), bitterns, hawks, owls, fishers, American bullfrogs, large fish, and snakes.^[7] There are records during winter in Canada of hibernating adult common snapping turtles being ambushed and preyed on by northern river otters.^[6] Other natural predators which have reportedly preyed on adults include coyotes, American black bears, American alligators and their larger cousins, alligator snapping turtles.^[10] Large, old male snapping turtles have very few natural threats due to their formidable size and defenses, and tend to have a very low annual mortality rate.^[6]

These turtles travel extensively over land to reach new habitats or to lay eggs. Pollution, habitat destruction, food scarcity, overcrowding, and other factors drive snappers to move; it is quite common to find them traveling far from the nearest water source. Experimental data supports the idea that snapping turtles can sense the Earth's magnetic field, which could also be used for such movements (together with a variety of other possible orientation cues).^[11][12]

This species mates from April through November, with their peak laying season in June and July. The female can hold sperm for several seasons, using it as necessary. Females travel over land to find sandy soil in which to lay their eggs, often some distance from the water. After digging a hole, the female typically deposits 25 to 80 eggs each year, guiding them into the nest with her hind feet and covering them with sand for incubation and protection.^[13]

Incubation time is temperature-dependent, ranging from 9 to 18 weeks. In cooler climates, hatchlings overwinter in the nest. The common snapping turtle is remarkably cold-tolerant; radiotelemetry studies have shown some individuals do not hibernate, but remain active under the ice during the winter.^[13]

In the northern part of their range snapping turtles do not breathe for more than six months because ice covers their hibernating site. These turtles can get oxygen by pushing their head out of the mud and allowing gas exchange to take place through the membranes of their mouth and throat. This is known as extrapulmonary respiration.^[14]

If they cannot get enough oxygen through this method they start to utilize anaerobic pathways, burning sugars and fats without the use of oxygen. The metabolic by-products from this process are acidic and create very undesirable side effects by spring, which are known as oxygen debt.^[14] Although designated as "least concern" on the IUCN redlist, the species has been designated in the Canadian part of its range as "Special Concern" due to its life history being sensitive to disruption by anthropogenic activity.^[15]

Systematics and taxonomy

 

Currently, no subspecies of the common snapping turtle are recognized.^[16] The former Florida subspecies osceola is currently considered a synonym of serpentina, while the other former subspecies Chelydra rossignonii^[17] and Chelydra acutirostris are both recognized as full species.^[16][18]

 

 

 Native range map of C. serpentina

 

 

 

 

 

THE NEOTROPICAL OTTER

 

The neotropical otter or neotropical river otter (Lontra longicaudis) is a near-threatened (per the IUCN) otter species found in freshwater systems from Mexico and Central America through mainland South America, as well as the island of Trinidad. It is physically similar to the northern (L. canadensis) and southern river otter (L. provocax), which occur directly north and south of this species' range, respectively. Its head-to-body length can range from 36–66 centimetres (14–26 in), plus a tail of 37–84 centimetres (15–33 in). Body weight ranges from 5–15 kilograms (11–33 lb).^[3]

  

At the Corrientes Zoo, Argentina

The neotropical otter is found in many different riverine habitats and riparian zones, including those in tropical and temperate deciduous to evergreen forests, savannas, llanos (of Colombia and Venezuela) and the pantanal (in Bolivia, Brazil and Paraguay). It prefers to live in clear, fast-flowing rivers and streams, preferably away from competition with the more boisterous giant otter (Pteronura brasiliensis). Unlike other otters (including the aforementioned giant species), which live in large and cohesive socio-familial units, the neotropical otter is a relatively solitary animal, feeding mostly on fish and crustaceans.

The taxonomy of the genus Lontra has been debated, but the use of Lontra rather than Lutra for New World otters is generally supported. The Neotropical otter has a very wide range, covering a large portion of South America, so it is not surprising there are geographical structures separating some populations. One such geographical isolation is the Cordillera Mountains. Additionally, the river in the Magdellena river valley flows north, away from the mountains, decreasing the likelihood that otters in the northern tip of South America will mix with otters elsewhere in the continent.

Neotropical otters have an unusual phylogenic relationship to other otter species. They are most similar to marine otter (Lontra felina) and southern river otter (Lontra provocax), which is not surprising considering these two species are found in South America. However, Neotropical otters are relatively distantly related to giant otter (Pteronura brasiliensis), which is surprising considering they have nearly identical ecological niches and home ranges.^[4]

In one study, otters within a 1,600 sq mi (4,100 km²) area in southern Brazil showed low nucleotide variation, but high haplotype diversity compared to other otter species and other carnivores. The study made the conclusion that otters may be undergoing a recent increase in diversity. The results also show interrelatedness of otters nearby and give reason to separate the species into subspecies:^[5]

 

 The Neotropical otter is covered in a short, dark grayish-brown pelage. Fur color is lighter around the muzzle and throat.^[6] 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.^[7] Its head-and-body length can range from 36–66 centimetres (14–26 in), plus a tail of 37–84 centimetres (15–33 in).^[3] Body mass of the otter generally ranges from 5 to 15 kilograms (11–33 pounds). Neotropical otters will communicate with nearby otters via scent marking. Communication may also occur via whistles, hums, and screeches.^[7]

The dental formula seldom varies from that of Eurasian otters (Lutra lutra), except in the few cases of otters that have dental anomalies.^[8] Females and males have the same formula. The dental formula (for half the skull) is as follows:^[9]

A neotropical otter in Bioparque Ukumarí, Colombia

The Neotropical otter has the widest distribution of all the Lontra species. Their habitat can range from northwest Mexico to central Argentina. They prefer clear, fast-flowing rivers, and are rarely known to settle in sluggish, silt-laden lowland waters or boggy areas. While mostly occurring at 300–1,500 m (980–4,900 ft) above sea level, they have been found settled at 3,000 m (9,800 ft).^[10] They require dense riparian vegetation and abundant den sites but, other than that, the Neotropical otter is very versatile and tolerant to environmental change. The otters prefer den sites that are solid, high, dry, and in proximity to deep water.^[11] The Neotropical otter is the greatest generalist of all otter species. In addition to rivers and streams, they can settle in and exploit some rather formidable habitats, such as wastewater treatment plants, rice paddies, sugar cane plantations, estuaries, deltas, drainage ditches, and sometimes swamps. They can inhabit cold, glacial lakes and streams in the Andes of Ecuador and Colombia.^[12] Neotropical otters will also venture to the seashore and beaches (maintaining an almost "brackish" lifestyle), hunting marine creatures and playing in the highly saline water.^[13]

The Neotropical otter's diet consists mostly of fish and crustaceans making up 67% and 28%, respectively, of its total diet. The otter will also occasionally feed on mollusks and small mammals, as well as birds, large insects and fruits.^[14][15] In areas where fish and crustaceans are scarce, aquatic insects, such as dobsonfly larvae, can become its main prey.^[16] This otter is known to occasionally attack fishnets for a source of prey, hindering fishing productivity.^[13] Otters living near marine habitats can have a much higher proportion of crustaceans in their diets.

Seasonality also greatly affect otters' food choice. During the dry season, when less fish and crustaceans are available, one study found a higher proportion of frogs in otters' diet. Though, during this time, anurans and reptiles still made up a very small percentage of the total diet. This might also be due to the fact that certain frogs mate during the dry season, so the frogs are easier prey. All in all, the distribution of available food species in a particular area roughly correlates to the percentage of each species found in otters' diet.^[17]

Breeding occurs mostly in spring. Gestation will last 56 days and produce a litter of 1–5 pups.^[6] 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.^[11] 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.^[18]

 In an ecologically healthy area, there are many possible shelters so an individual can choose its preferred den. However, studies show that not all possible shelters are occupied and not all shelters are equally utilized by Neotropical otters. Otters visit different shelters with varying frequencies, from once or few times per up to many times per year. One factor that influences their preference for a den has to do with the water level, especially during flood season, when a den near water level can easily be washed away. A den may be at the water level, near the bank, or more than 1.5 meters about the water level.^[19]

 There are many other factors influencing otters' preferences for a shelter. Neotropical otters prefer dens near fresh water, high food availability, and relatively deep and wide water. During seasons with low water, individual otters may be more clumped because they will all move into areas of a river with deeper water, with more fish.^[19] Deep, wide pools have been found to have a greater diversity of fish, preferential for otters. Some studies show that otters will forgo a less preferable, but more available den, like a muddy river bank, to spend more time in a preferential den, like a rocky shore.^[20]

Neotropical otter 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-kilometer 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.^[21]

 

 Dens may have more than one opening, so the otter can easily exit to forage for food while staying safe from predators. There are many classifications of dens that Neotropical otters may use. A cavity among stones or under tree roots is preferred. In certain parts of South America, an otter may come across a limestone dissolution cavity or a cavity in a rocky wall. Though lacking a source of light, the Neotropical otter can make great use of this sturdy home. As a last resort, an otter expend energy to excavate a space among vegetation or a river bank, though those homes are less sturdy. Vegetative cover is also very important for the Neotropical otter. In comparison to other otter dens, the Neotropical otter dens do not have holes directly into the water, they do not use plant material as bedding, and will live in caves without light. They are elusive creatures and prefer undisturbed forests without signs of human activity. When humans clear forests for agricultural land, the number of available otter habitats plummets.^[19]

Like other otter species, Neotropical otters will mark their territory with scratching or spraint (feces) in obvious places like rocks and under bridges.^[22] 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 center 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.^[19]

The niches and ranges of the giant 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. The giant otter is much larger and hunts in groups, so it can take larger prey. Some areas, like the Pantanal, have high enough productivity such that both otter species can coexist with little or no competition (niche partitioning). Additionally, Neotropical otters prefer deeper and wider streams than giant otters.^[12]

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.^[23] Although there have been attempts at captive breeding, these attempts have been largely unsuccessful.^[6]

 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. 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 towards them, and build on to currently insufficient data about this species. Otters are rarely get caught in gillnets, and when they do they very rarely die.^[24]

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.^[20]

One male and one female Neotropical otter were captured near Caucasia, Colombia, and taken to Santa Fe Zoological Park in 1994 and 1996, respectively. Zoo staff observed the pair mating in the water, then separated the animals. The female had three births; one was successful. The infant deaths may have been unintentionally caused by the mother. One idea suggested the mother's enclosure was too small and she had no access to water, as she would have had in the wild. The mother's gestation period was 86 days for two separate breeding events recorded at this zoo. An 86-day gestation period is much longer than the previously accepted belief that gestation lasts around 60 days. Two possible explanations are: differences might exist between different subspecies or a later copulation may have occurred and not been observed. Also, this otter species might display short-term variation in gestation periods.^[18]