Spectacled caimans are small to medium-sized crocodilians generally 1.5 to 2.1 meters in length. Historically, maximum reported length was 3 m. At current levels of exploitation, few specimens exceed 2.5 m in length. Females are smaller than males. Average adults are a dull olive to nearly black in color with variable yellow or black cross bands. They have long snouts and their fourth mandibular tooth is not visible from the outside of their closed jaw. Juveniles are yellowish in color with darker bands and spots. A feature that helps to distinguish Caiman crocodiles from other, sympatric crocodilians is the presence of a bony infra-orbital bridge between the eyes. Subspecies vary in color and skull size.
HABITAT AND ECOLOGY The Spectacled Caiman is a medium-sized crocodilian (maximum total length in males 2.7 m; Ayarzagüena 1984), that is extremely adaptable in terms of habitat requirements, occupying rivers, creeks (caños), lagoons, lakes, borrow pits, swamps, wetlands, dams, and marshes (Medem 1981). Female Spectacled Caimans reach sexual maturity at about 1.2 m total length and lay an average of 28-32 eggs in a mound nest, usually during the annual wet season (Thorbjarnarson 1994; Velasco et al. 1996). A close relationship between precipitation in certain months and the proportion of females that reproduce in that year has been reported (Ayarzagüena and Castroviejo 2008). Ayarzagüena and Castroviejo (2008) summarize the species’ ecology and behavior in detail. They comment that the genus Caiman, along with Alligator, shows the most elaborate behaviors known in crocodilians. Spectacled caiman behavior includes complex sound signals: “warning calls” emitted by female to the young; “distress call” emitted by juveniles; and, “group cohesion calls” emitted by all individuals. Males display social behaviours: “vertical tail” and “arch tail” with sub-audible vibrations, barks, and visual displays. Another important characteristic described by these authors is that hatchling and juvenile groups remain together under female care for 12-18 months. Initial studies on Spectacled caiman ecology were conducted in both the Venezuelan llanos and Colombian Caribbean (e.g., Chirivi 1973; Staton and Dixon 1975; Medem 1981; Seijas 1984, 1986). Subsequent studies report on life history traits such as feeding habits (Thorbjarnarson 1993, Allsteadt and Vaughan 1994, Da Silveira and Magnusson 1999, Bontemps et al. 2016), nesting ecology (Chirivi 1971, Staton and Dixon 1977, Thorbjarnarson 1994, Escobedo-Galván 2006, González-Desales et al. 2016), morphology (Busack and Pandya 2001, Macip-Ríos et al. 2012, Okamoto et al. 2015), parasites (Magnusson 1985, Charruau et al. 2016), injuries (Magnusson 1985, Seijas et al. 2003), growth (Magnusson and Sanaiotii 1995, Pérez 2001), and some demographic parameters (e.g., Allsteadt and Vaughan 1992a; Bolaños et al. 1997; Cerrato 1991; Flores 2005; Escobedo-Galván and González-Maya 2006, 2008; Martinez-Ibarra et al. 1997; Ouboter and Nanhoe 1987, 1988; Pacheco 1990; Ron et al. 1998; Perez 2001; Balaguera-Reina et al. 2010; Balaguera-Reina 2012; Moreno-Arias et al. 2013; Barão-Nóbrega et al. 2018). The Spectacled Caiman appears to have been resilient to commercial hunting for several reasons, particularly the small size and young age at which reproduction commences and hunting focus on large adult males. Additionally, Spectacled Caimans lay eggs on almost any type of substrate, and this lack of selectivity is advantageous over other more selective sympatric species (e.g., C. acutus, C. intermedius). The near extirpation of larger, sympatric crocodilian species of greater commercial value, may have assisted Spectacled caimans. In Brazilian Amazonia, they occupy habitats formerly dominated by Melanosuchus niger (Magnusson 1982). In the llanos of Venezuela and Colombia, the proliferation of man-made water bodies (e.g., borrow pits) has increased the carrying capacity for caiman populations. The ecological adaptability of the Spectacled caiman is evidenced through its rapid population growth where it has been introduced, both accidentally and deliberately. Introduced (feral) populations are established in the United States (especially Florida), Puerto Rico (Watlington 2002), Cuba (under harvest since 1995, Berovides et al. 2000) and Colombia (San Andres and Gorgona Island; Forero et al. 2006, Velasco and Balaguera-Reina 2018).
From youngsters to adults, spectacled caiman tend to eat animals they find in the water. Although the youngest ones will eat insects and other invertebrates they find on land, juveniles are fond of snails, and adults mainly eat different types of fishes.
Lakes and ponds, rivers and streams, coastal, brackish water.
Several conservation programs have been initiated with the participation of communities, private enterprises and environmental authorities. From 2004 to 2006, a pilot program was developed in Colombia for harvesting, egg incubation and breeding of caimans by fishing communities. The hatched individuals were raised for a year and released in different swamps of the Canal del Dique (Bolivar Department), in the same areas where the eggs were originally harvested (Fundación Biodiversa 2004). Based on the successful experiences of the Canal del Dique program, a larger program was implemented in the Atlántico Department between 2005 and 2009, involving the reintroduction of over 15,000 yearling and sub-adult individuals, which comprised the repopulation quotas of the closed-cycle breeding farms, into the wetlands where the species had been almost totally removed (Palencia et al. 2006, Rojano and Velasco 2006, Rueda et al. 2007, Medrano and Rojano 2009). Currently, studies are in place around the country to assess potential pilot areas for ranching under standardized conditions that allow local people to use caimans without affecting the conservation status of the species. Conservation priorities for the species have been defined by Velasco and Balaguera-Reina (2018) and can be consulted in the IUCN SSC Crocodile Specialist Group Action Plan for Caiman crocodilus. Population surveys in Guyana and Nicaragua are considered high priority due to harvest of wild C. crocodilus in these countries being harvested based on annual quotas. No information regarding the conservation status of the species has been collected in the last few decades. Increased research into the ecology, population dynamics, conservation, and population genetics in areas under commercial use regimes (e.g., wild harvesting, captive breeding, ranching) will help define the sustainability of use programs and populations over time. Population surveys are also required in Ecuador, El Salvador, French Guiana, Guatemala, Honduras, Panama, Peru, Suriname, Trinidad and Tobago to determine the conservation status of the species as well as identify and mitigate potential issues with local use. Population surveys in areas where the species has been introduced and is considered ‘established’ (Cuba, insular Columbia (San Andres and Gorgona Islands), and Puerto Rico), are needed to assess the impact of this non-indigenous species on local fauna. Sustainable use programs might be an option for controlling introduced Spectacled caiman populations.
CLASS : Reptilia
ORDER : Crocodylia
FAMILY : Alligatoridae
GENUS : Caiman
SPECIES : Spectacled Caiman (Caiman crocodilus)
Conservation status : Vulnerable
Spectacled caimans reach sexual maturity at sizes of about 1.2 meters for females and 1.4 meters for males, corresponding to from 4 to 7 years old. Courtship and copulation occurs between May and August. Eggs are laid from July to November, depending on local climatic conditions. Females lay from 10 to 30 eggs. Incubation usually requires between 65 and 104 days.
Update : 11 April 2017