Cuvier’s Dwarf Caiman14/04/2021
Cuvier’s Dwarf Caiman (Paleosuchus palpebrosus) is a small crocodilian in the alligator family from northern and central South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela. It lives in riverine forests, flooded forests near lakes, and near fast-flowing rivers and streams. It can traverse dry land to reach temporary pools and tolerates colder water than other species of caimans. Other common names for this species include the Musky Caiman, the Dwarf Caiman, Cuvier’s Caiman, and the Smooth Fronted Caiman. It is sometimes kept in captivity as a pet and may be referred to as the wedge-head caiman by the pet trade.
Cuvier’s Dwarf Caiman is the smallest living new world crocodilian. Males grow to a maximum length of around 5.2 ft while females do not usually exceed 3 ft 11 in. The largest specimen on record measured 5.6 ft in length. This may be an underestimate of the animal’s maximum size, as nearly all large adults have lost the tips of their tails and the largest specimen measured in the Pantanal region had a snout-vent length of 4 ft (equivalent to a total length of 6.9 ft with an intact tail). An adult typically weighs around 13 to 15 lb, around the same weight as a 6 – to the 12-month-old specimen of several larger species of crocodilians. Cuvier’s Dwarf Caiman has strong body armour on both it is dorsal (upper) and ventral (lower) sides, which may compensate for its small body size in reducing predation. The dermal scales providing this protection have a bony base and are known as osteoderms.
The head has an unusual shape for a crocodilian, with a dome-shaped skull and a short, smooth, concave snout with an upturned tip, the shape rather resembling the head of a dog. The upper jaw extends markedly further forward than the lower jaw. Four premaxillary and 14 to 15 maxillary teeth are on either side of the upper jaw and 21 or 22 teeth on each side of the lower jaw, giving a total of about 80 teeth. The neck is relatively slender and the dorsal scutes are less prominent than in the smooth-fronted caiman. The double rows of scutes on the tail are small and project vertically. Adults are dark brownish-black with a dark brown head, while juveniles are brown with black bands. The irises of the eyes are chestnut brown at all ages and the pupils are vertical slits.
Cuvier’s Dwarf Caiman is native to tropical northern and central South America. It is present in the drainages of the Orinoco River, São Francisco River, and the Amazon River, and the upper reaches of the Paraná River and the Paraguay River. The countries in which it is found include Peru, Ecuador, Colombia, Venezuela, Guyana, Suriname, French Guiana, Brazil, Bolivia, Trinidad and Paraguay. The range of this species is rather larger than that of the sympatric smooth-fronted caiman, as it extends into Paraguay and includes a larger area of Brazil.
Cuvier’s Dwarf Caiman is a freshwater species and is found in forested riverine habitats and areas of flooded forest around lakes. It seems to prefer rivers and streams with fast-flowing water, but it is also found in quiet, nutrient-poor waters in Venezuela and southeastern Brazil. It is able to travel quite large distances overland at night and subadult individuals have sometimes been found in isolated, temporary pools. In the northern and southern parts of its range, it is also found in gallery forests in savanna country, but it is absent from such habitats in the Llanos and the Pantanal. Cuvier’s Dwarf Caiman seems relatively tolerant of cool water compared to other species of caimans. During the day, individuals sometimes lie up in burrows but at other times rest on piles of rocks or sun themselves while lying, facing the sun, in shallow water with their backs exposed.
These Caimans are mainly nocturnal. Adult Cuvier’s Dwarf Caimans are usually found singly or in pairs. The breeding of this species has been little studied, but it does not appear to be seasonal in nature. The female builds a mound nest out of vegetation and mud somewhere in a concealed location and lays a clutch of 10 to 25 eggs, hiding them under further vegetation. The period is around 90 days and the sex of the hatchlings depends on the temperature of the nest during that time. When the eggs begin to hatch, the female opens the nest in response to the calls made by the young. Newly emerged juveniles have a coating of mucus and may delay entering the water for a few days until this has dried. Its continuing presence on their skin is believed to reduce algal growth. The female stays with the young for a few weeks, after which time the hatchlings disperse. The young grow at a rate around 3 to 4 in per year and reach sexual maturity around 8 years old.