Caiman crocodilus, the spectacled, common, or brown caiman, is a crocodilian native to northern South America, Central America, and certain parts of the Caribbean. They are native to the following countries: Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname, Trinidad, Tobago, and Venezuela. They have been introduced into Florida, Cuba, and Puerto Rico.

Biogeographic Regions: nearctic (Introduced ); neotropical (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Mexico, Central and much of South America; apparently occasionally vagrant to Grenadines (Schwartz and Henderson 1991). Introduced and reproducing in south Florida (Ashton and Ashton 1985). Largest known breeding population in Florida is at Homestead Air Force Base, Dade County; breeding populations probably occur also in western Dade County; juveniles and adults have been observed in Ft. Lauderdale, Broward County; low resistance to cold probably will prevent spread of currently established populations northward to areas that experience routine freezes (Brandt and Mazzotti 1990). Introduced also in Puerto Rico and Isla de la Juventud. Recorded also in Virginia (Mitchell 1994; D'Alessandro and Ernst 1995, Herpetol. Rev. 26:212-214).

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 crossbands. 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 crocodilus from other, sympatric crocodilians is the presence of a bony infra-orbital bridge between the eyes. Subspecies vary in color and skull size.

Range mass: 7 to 58 kg.

Average mass: 40 kg.

Range length: 1.5 to 3 m.

Average length: 2 m.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: male larger

Length: 264 cm

• Terrestrial
• Freshwater

Spectacled caimans are found in freshwater habitats as well as some salt water habitats. Rivers and wetlands, usually slow moving water, are preferred. They are found in both deep and shallow water, as they only need enough depth to submerge their bodies.

Range elevation: 800 (high) m.

Habitat Regions: tropical ; terrestrial ; saltwater or marine ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh ; swamp ; bog

Other Habitat Features: riparian ; estuarine

Comments: Ponds, creeks, rivers, marshes, and drainage canals (Behler and King 1979); occasionally in brackish estuaries (Schwartz and Henderson 1991). In Suriname, swamp-bordered river parts usually had higher population densities than did forest-bordered river parts; most juveniles and subadults found in area with much aquatic vegetation; dispersed into inundated swamps during high water (Ouboter and Nanhoe 1988).

Eggs are laid in a mounded nest of soil and vegetation (Behler and King 1979), at times some distance from water (Schwartz and Henderson 1991). In Brazil, nested in forest and on floating grass mats (Campos 1993). In Costa Rica, nested in forest adjacent to rivers or canals (Allsteadt 1994).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Spectacled caimans are carnivorous generalists. Prey items change as they grow from smaller to larger caimans. Prey can include insects, snails, shrimp, crabs, fish, lizards, snakes, turtles, birds, and mammals. Spectacled caimans have at least 105 prey items reported in their diet. Cannibalism can occur, especially under drought conditions, when many caimans of different sizes are concentrated in small areas. However this species can be surprisingly unaggressive and tolerant of temporarily dense concentrations during the dry season.

Animal Foods: birds; mammals; amphibians; reptiles; fish; carrion ; insects; terrestrial non-insect arthropods; mollusks; aquatic crustaceans

Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore , Insectivore , Eats non-insect arthropods, Molluscivore , Scavenger )

Comments: Eats fish, amphibians, reptiles, small birds and mammals, snails, crabs and other crustaceans, and insects; diet may shift seasonally and ontogenetically (Behler and King 1979, Herpetologica 49:108).

Spectacled caimans are predators of aquatic invertebrates, fish, and other aquatic and shoreline vertebrates. In their native range they are important members of riparian shoreline and aquatic communities. Where spectacled caimans have been introduced outside of their normal range, spectacled caimans may have unpredictable, perhaps deleterious effects on prey species.

During nesting time, tegu lizards (Tupinambis sp.) can destroy up to 80% of caiman nests in some places. Coatis (Nasua narica) and foxes also raid nests. Juveniles are eaten by large fish, wading birds, large snakes, and other crocodilians. Adult spectacled caimans are able to defend themselves from most potential predators, except humans.

Known Predators:

• tegu lizards (Tupinambis teguixin)
• coatimundis (Nasua narica)
• herons (Ardeidae)
• large fish (Actiinopterygii)
• other crococilians (Crocodilia)
• anacondas (Eunectes sp.)
• humans (Homo sapiens)

Anti-predator Adaptations: cryptic

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Many occurrences but the actual number is unknown.

10,000 to >1,000,000 individuals

Comments: Presumably over 10,000 individuals rangewide.

Under certain favorable conditions, up to 80+ caimans observed per stream km in Suriname; relatively sedentary; for individuals relocated after intervals of up to 1 year, greatest movement was 3 km (Ouboter and Nanhoe 1988).

In Brazil, flooding of nests and predation were the major mortality agents of eggs (Campos 1993).

Spectacled caimans use taste, touch, sound, and visual senses for social and reproductive communication. The ability to detect vibrations in the water may aid in prey detection.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: vibrations

Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical

Some weeks after courtship and copulation, with internal fertilization, females lay their oval, hard-shelled eggs in a newly made mound of leaf litter and other vegetation. Once the eggs are laid, the female will cover the nest. Females, and sometimes males, guard their eggs against nest predators. Temperature influences sex determination during incubation. An average nest temperature of 30 degrees C will produce mostly females and 34 degrees will produce mostly males. After an incubation period of 65 to 104 days the babies will hatch out of their eggs and move to the nearest water, with some help from their parents. Once the juveniles have hatched, they will stay near their parents for about 1.5 years. Juveniles then grow to adult size at around 1.2 to 1.4 meters in length. Once juveniles reach minimum adult size, they are able to reproduce. If they survive long enough, they can continue to grow until reaching a size that may exceed 2.4 meters.

Development - Life Cycle: temperature sex determination

There is very little known about the lifespan of Caiman crocodilus. The longest known lifespan in the wild was estimated at about 60 years old. However, 30 to 40 years might be more normal. The average captive lifespan is 20 years, with a minimum record of 24 years.

Range lifespan

Status: wild: 60 (high) years.

Range lifespan

Status: captivity: 24 (high) years.

Typical lifespan

Status: wild: 30 to 40 years.

Average lifespan

Status: captivity: 20 years.

Mating typically occurs in the wet season from April to August, depending on local climatic conditions. Males can breed with multiple females and females can breed with multiple males. Courtship behavior involves prospective mates swimming together, rubbing backs, bellowing, touching snouts, circling each other, and bubble-blowing. Both sexes use these behaviors to attract their mates. After a female mates with a male she will build a nest in the males territory. There, the male and female will guard the nest, eggs, young, once they are hatched.

Mating System: polygynandrous (promiscuous) ; cooperative breeder

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. Social status affects growth rate and reproduction. Some younger, smaller caimans will be unable to mate because of social stress because of the presence of larger, more dominant caimans. 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. Sex is determined by temperature in the nest about midway through incubation. The decomposing vegetation in the nest, which may be a meter high and 2 meters in diameter, may help retain temperatures at the proper level. After hatching, the parents may excavate the juveniles from the nest and help them out of the eggshell. Once emerged, juveniles stay near their parents for approximately 1.5 years, receiving some protection from predators.

Breeding interval: Spectacled caimans breed for about four months during the wet season each year.

Breeding season: Spectacled caimans breed from May through August.

Range number of offspring: 10 to 40.

Average number of offspring: 22.

Range gestation period: 65 to 104 days.

Range birth mass: 46 to 55 g.

Average time to independence: 1.5 years.

Range age at sexual or reproductive maturity (female): 4 to 7 years.

Average age at sexual or reproductive maturity (female): 6 years.

Range age at sexual or reproductive maturity (male): 4 to 7 years.

Average age at sexual or reproductive maturity (male): 6 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous

After copulation, females, sometimes assisted by males, build a nest out of leaf litter. Females lay their eggs in the nest and then cover it with more leaf litter. Females, and occasionally males, guard the nest from predators until they hear the babies call with grunt-like squeaks. Females then help uncover eggs and break the shells open to get the juveniles out. At that point, juveniles stay near their mother, and sometimes within the male parent's territory, for around 1.5 years for additional protection from predators. The parents may incidentally provide some food scraps for the juveniles but, for the most part, juvenile caimans catch food for themselves. After about 1.5 years with their parents, juveniles disperse from their parent's territory. In some situations, young caimans remain closer to their parents for longer periods.

Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Female)

In the Venezuelan llanos, nests in the wet season, mid-August to late October; eggs hatch late December-early January (see Fitch 1982, Thorbjarnarson 1994). In Costa Rica, nested during early wet season; eggs hatched in September and October; typically, parent caimans opened nests to release young; flooding was a major cause of embryonic mortality (Allsteadt 1994). Clutch size averages usually about two dozen. and Henderson (1991), incubation lasts about 75 days; female (and male?) remains in vicinity of nest throughout incubation. Sex of hatchlings is determined by incubation temperature. In Costa Rica, siblings often remained together for over 1.5 years (Allsteadt 1994). In Venezuela, males and females attained sexual maturoty in about 7 years, though small mature males may not have reproduced because of social factors); an average of 54% of adult-size females nested annually, with reproductive output increasing with size (Thorbjarnarson 1994). In central Amazonia, Brazil, females probably reached sexual maturity at between five and six years of age (Magnusson and Sanaiotti, Copeia 1995:498-501).

In 1986 and 1988 spectacled caimans were listed by the United States Fish and Wildlife Service as a threatened species. This was due to increased hunting pressure on their populations. Caimans are heavily harvested for their skins to make leather products. The pet and curio trade has also had some degree of responsibility for local population declines. Spectacled caiman populations are still relatively stable in some parts of their range, although they are severely depleted or extirpated in many local areas, especially near human population centers.

US Federal List: threatened

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: lower risk - least concern

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: G3 - Vulnerable

Reasons: Wide range in the subtropical and tropical regions of the New World; introduced and established in Florida; probably declining in many areas from due to habitat loss/degradation and excessive exploitation by humans, but supporting documentation is not available for most areas.

Global Short Term Trend: Unknown

Comments: Trend is unknown, presumably declining in areas experiencing wetland losses and excessive human exploitation.

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Endangered by persistent hunting in the Caatinga of northeastern Brazil (Olmos and Souza 1991). Also in Brazil, threatened by destruction of floating grass mats by introduced water buffalo; caiman uses mats for nesting (Campos 1993).

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: At least several protected occurrences.

Spectacled caimans are potentially dangerous to humans and pets, and they occasionally attack livestock. Their smaller size compared to other crocodilians makes them less of a threat. They become shy and avoid humans in areas where they are frequently hunted. Spectacled caimans have been introduced outside their natural range, such as in southern Florida, and possible negative effects on local naive wildlife are in need of study.

Negative Impacts: injures humans (bites or stings)

Within their native range, spectacled caimans are usually the most abundant crocodiles and are the most heavily harvested species by humans for the hide industry.

Positive Impacts: pet trade ; food ; body parts are source of valuable material; controls pest population

Comments: In 1979, santioned trade exceeded 500,000 skins, essentially all of which resulted from hunting of wild populations (Magnuson 1984). See Thorbjarnarson (1999) for a discussion of the limits to sustainable use of crocodilians.

Comments: Busack and Pandya (2001) examined geographic variation in morphology in Caiman crocodilus and found basis for the recognition of subspecies, and they concluded that C. yacare should not be regarded as a subspecies of C. crocodilus. See Densmore and White (1991) for a phylogeny of the Crocodylia based on molecular data.