10/18/2024
Day 19 Spectacled Caiman
The spectacled caiman is a small to medium-sized crocodilian. Females generally grow to no more than 1.08 to 1.4 m (3 ft 7 in to 4 ft 7 in) (the lower size typical upon the onset of s*xual maturity), but can rarely grow to nearly 2 m (6 ft 7 in). Adult males can regularly reach 1.5 to 1.8 m (4 ft 11 in to 5 ft 11 in) while large mature ones grow to 2.0 to 2.5 m (6 ft 7 in to 8 ft 2 in), although relatively few get to the upper size. The maximum reported size for the species is 2.64 m (8 ft 8 in). The body mass of most adults is between 7 and 40 kg (15 and 88 lb), with males typically being considerably heavier than females. Some males in the Llanos have been reported to grow to up to 58 kg (128 lb).
The upperside of the species is mostly brownish-, greenish-, or yellowish-gray colored and has dark brown crossbands, with a lighter underside. It has a greenish iris.[19] and wrinkled eyelids. It changes color seasonally – during colder weather, the black pigment within its skin cells expands, making it appear darker. The species has an enlarged 4th tooth, and the teeth in its lower jaw pe*****te into a socket in its upper jaw. It has a long snout that tapers moderately, with an unexpanded tip. Several ridges begin in front of its eyes and travel to the tip of its snout. Its common name comes from a bony ridge between its eyes, which gives the appearance of a pair of spectacles. The spectacled caiman is the most widely distributed New World crocodilian, and is the most geographically variable species in the Americas, making it a highly adaptable species.
Usually hunting at night, the diet of the spectacled caiman varies seasonally. During the wet season, it primarily eats snails and freshwater crabs, while it mostly eats fish in the dry season. Smaller specimens tend to eat more insects and freshwater shrimp, while larger ones more frequently consume mammals and fish. Overall, the most common animals in this species' diet are crabs, other crustaceans, fish, mammals, snails and other molluscs. Other animals that have been known to be a part of its diet include amphibians, arachnids, birds, myriapods, reptiles (lizards, snakes, and turtles), and small mammals. Older animals are capable of taking larger, mammalian prey (e.g. wild pigs).
The spectacled caiman uses nine different vocalizations and 13 visual displays to communicate with individuals of its species. Both adults and young produce calls for group cohesion. Males are known to communicate by moving their tail to a certain position, such as making it vertical or arched. Juveniles vocalize when in distress and adult females emit calls to warn young of threats.
The spectacled caiman reaches s*xual maturity from four to seven years old, at a length of 1.2 metres (3.9 ft) for females and 1.4 metres (4.6 ft) for males. Usually, the more dominant individuals mature more quickly. There is no strict reproductive hierarchy in spectacled caiman, but studies show larger males have more success breeding. Specimens choose mates and engage in copulation from May to August, the wet season. The females build nests as a mound of dense vegetation, in areas that are close to water but not at risk of being flooded. The nests are over 1 metre (3.3 ft) in diameter and can be 40 centimetres (16 in) high, but the exact size depends on the resources available. Eggs are laid in July and August; the species very rarely nests in the winter, as the temperature is too low for the eggs. Clutch size is 22 on average, but can range from 14 to 40. Larger females have been known to lay larger eggs compared to smaller females. Females stay close to their nests during the incubation period, as several species, such as lizards in the genus Tupinambis, have been known to destroy nests and prey on the eggs. White-nosed coatis and foxes also raid nests. Flooding and human egg collecting can also be a threat to the nests. In a study in the Central Amazonia assessing reproductive similarities between C. crocodilus and Melanochus niger, research found that they indiscriminately separate their nests at larger distances than other species in this family, most likely to avoid predation.
Temperature is important to the developing eggs, so females build their nests in a way that insulates them from extreme temperature changes. As the vegetation in the nests decays, the nests produce heat which can keep the eggs about 5 °C (9 °F) warmer than if they were insulated by mud alone. Heat not only incubates the eggs, but also determines the s*x of the developing caimans (temperature-dependent s*x determination). When the temperature inside the nest is about 32 °C (90 °F) or higher, the caimans become female, and otherwise become male.Young hatch after 90 days, with 20–25 percent of eggs hatching successfully. They are yellow with black spots, a coloration which fades away as they grow older, with a length of 20–23 centimeters (7.9–9.1 in). Parents raise their young in crèches, with one female taking care of her own, as well as several others' offspring. They take care of their young for 12–18 months. Young are threatened by various predators, such as raptors (like hawks) and wader birds (like herons),causing most to die in their first year. These juveniles are also preyed upon by large fish, large snakes (such as anacondas), and other crocodilians.
Spectacled caimans can survive up to 75 years in the wild.
