Black caiman typically hunt at night, using their acute sight and hearing to locate their prey (2). Fish comprise the major part of the black caiman's diet, particularly catfish and the much-feared piranha, but adult black caiman also tackle much larger prey such as capybara, turtles and deer (4). Domestic animals such as dogs and pigs may be taken by large adult caiman, and there are even reports of people being the victim of an attack. Juvenile black caiman stick to smaller foods, including crustaceans, other invertebrates such as snails, and fish (4). Female black caiman are thought to start nesting during the dry season when water levels fall and fish are forced to congregate in shallow pools, providing an easy and plentiful meal (4). Plant material is used to build a mound nest measuring about 1.5 metres across, into which a large clutch of up to 65 eggs are laid (4). The female will remain close to the nest, waiting for between 42 and 90 days until the eggs begin to hatch, before opening the nest to assist with the hatching process (2). As many females often nest within close proximity, large numbers of hatchlings all emerge at once at the beginning of the wet season, gaining some safety in numbers (2).

This impressive aquatic hunter is the largest of all alligator species, with reports of individuals measuring six metres (2). The black caiman superficially resembles the American alligator (4), and as its name suggests, its protective armoured skin is dark in colour. Pale yellow or white bands of dots pattern the sides of the body, while the lighter grey head has dark bands across the jaws (4). As the caiman matures, this banding gradually fades (2). The snout is fairly wide at the base but becomes rather narrow and pointed and (4), like other caiman, a bony ridge extends from above the large eyes, down the snout (2).

Black caimans are found throughout much of the Amazon Basin; their range includes much of northern and central South America. Although these animals are far less common now than a few decades ago.

Biogeographic Regions: neotropical (Native )

Continent: South-America
Distribution: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Venezuela  
Type locality: "Fluminis Amazonium et Solimoens", Brazil.

Historic Range:
Amazon basin

The black caiman occurs mainly in the Amazon Basin, although its range does also extend further north (4). It occurs in Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Venezuela (2), and in French Guiana, where the largest populations remain (4).

The largest predator in the Amazon, Melanosuchus niger is capable of growing to more than 6 m. It resembles the American Alligator but is biologically more closely related to the other caimans. The Black Caiman retains its distinctive skin markings into adulthood: they display grey or brown banding on the lower jaw, and display white or yellowish bands on the sides of the body (Britton 1999, Magnusson 1998).

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

Melanosuchus niger is often associated with steep banks alongside slow-moving freshwater rivers, lakes, wetlands, black water swamps, and seasonally flooded areas of the Amazon. (Britton 1999, Magnusson 1987).

Habitat Regions: tropical ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams

This aquatic reptile occurs in shallow, freshwater habitats such as slow-moving rivers, streams and lakes, and ventures into flooded savannah and wetlands (2) (4).

Studies on M. niger's diet are limited, but some have been carried out and the diet shows many similarities to that of the Common Caiman (Caiman crocodilus). This may be due to similar habitats.

Diets can vary depending on the age, size, habitat, and available prey. Mean prey size is usually positively correlated to caiman size.

Fish, such as piranhas and catfish, account for a large part of the adult Black Caiman's diet, as do molluscs. It also preys on aquatic and terrestrial vertebrates, including some mammals such as capybara (Hydrochaeris hydrochaeris). Young individuals tend to eat insects, crustaceans, and other invertebrates, but many of these are usually replaced in the diet as the caiman matures. Much hunting is done in the water, but the Black Caiman may emerge to hunt on land as well, usually at night (Britton 1999, Da Silveira and Magnusson 1999, Magnusson 1987).

Average lifespan

Sex: male

Status: captivity: 13.1 years.

Maximum longevity: 15.3 years (captivity)

Good information concerning the Black Caiman's breeding habits is not plentiful. In the dry season, which runs from September through December, the female builds a nest mound, using the hind feet to dig an egg chamber. Clutch size averages 39.3 eggs, which are elliptical, with rigid shells, and average 143.6g. The female generally remains close to the nest site, although not all actively defend the nest. She will scrape open the nest when the hatchlings are emerging. The incubation period lasts between two to three months, but may vary with nest temperature. Nests may be warmed by sunlight or by the heat of decomposing vegetation. Hatching may correlate with the onset of the rainy season.

Hatchlings tend to congregate together in groups called pods. Pods may contain individuals from more than one nest, and they are often protected by the adult female's presence. -M. niger- pods were found to occur in areas of deeper water than -C. crocodilus-, implying choice of nesting sites in lower-lying areas (Britton 1999, Da Silveira et al 1997, Herron 1990, Thorbjarnarson 1998).

The following is a representative barcode sequence, the centroid of all available sequences for this species. 

 
There are 4 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
 

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 4
Species: 5
Species With Barcodes: 1

While it was once extremely common throughout its range, commercial hunting has devastated populations of M. niger. Killing black caimans for their skins, which produce a shiny black leather, increased dramatically during the 1940s and 1950s as populations of other, more popular, South American crocodilians were decreasing. Hunting continued through the 1970s, nearly destroying many communities. It is estimated that black caiman populations have been reduced by 99% during the 20th century.

Illegal hunting remains a problem today, but it is not the only threat facing black caimans. The destruction of its habitat by deforestation and burning of swamplands is slowing the recovery of populations, as is increased competition for resources with Caiman crocodilus.

While still present in much of its range, populations are still severely depleted in 4 of the 7 countries in which it occurs. There are some locally strong populations in Peru, Ecuador, Brazil, and Guyana; these tend to occur in isolated, hard to reach areas of swampland. Thorbjarnarson and Da Silveira (1998) found a surprisingly robust population in the Mamiraua Reserve in the Amazon.

The lack of reliable census information makes population surveys a crucial first step for any management program. Ecological studies are also being carried out to help reveal the behavior of this poorly understood reptile.

Management strategies are focusing mainly on legal protection of wild populations, but such laws are not always effectively enforced. Bolivia pioneered a captive breeding and reintroduction program in 1990 by releasing 25 ranch-raised adult black caimans; some of these were observed to reproduce. There is hope that sufficient protection and population recovery may allow the implementation of a contolled, managed harvest that would benefit the local peoples. This would encourage protection of the species as a valuble resource and ease the pressures from uncontrolled poaching.

US Federal List: no special status

CITES: appendix i

IUCN Red List of Threatened Species: lower risk - conservation dependent

Current Listing Status Summary

Status: Endangered
Date Listed: 06/14/1976
Lead Region: Foreign (Region 10) 
Where Listed:


Population detail:

Population location: entire
Listing status: E

For most current information and documents related to the conservation status and management of Melanosuchus niger , see its USFWS Species Profile

Classified as Lower Risk / Conservation Dependent (LR/cd) on the IUCN Red List 2007 (1) and listed under Appendices I and II of CITES (3).

For many years, the black caiman was heavily hunted for its tough skin which produces shiny, black leather (2). Intensive hunting began in the 1940s, and continued into the 1970s and beyond (2) (4), with around an incredible 66,000 hides being exported from Colombia each year in the early 1970s (4). As a result of this extreme hunting pressure, the overall population of black caiman declined by 99 per cent over the last century and it is now virtually extinct in some locations, such as Colombia and the Amazon River itself (4). Illegal hunting continues to impact the black caiman, in addition to the destruction of its habitat, through deforestation and the burning of swamplands (2). Competition with the more numerous spectacled caiman (Caiman crocodilus) may also inhibit the recovery of black caiman populations (2). The impact of reduced black caiman numbers can be felt in some areas, such as Brazil and Bolivia, where capybara populations, free from this voracious predator, have increased, causing a rise in crop damage. Similarly, an increase in piranha numbers in flooded pastures has resulted in an increase in attacks on cattle (4).

Conservation Actions

Except for certain populations in Brazil and Ecuador, the black caiman is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species is only permitted in exceptional circumstances. Those other populations are listed on Appendix II of CITES, meaning that annual quotas are set and the trade is carefully monitored (3). In nearly all the countries in which the black caiman is found, the species is protected or is included in laws prohibiting commercial hunting. However, these laws can be difficult to enforce and illegal hunting remains a significant problem (5), compounded by the fact that black caiman skins can be difficult to differentiate from the more common spectacled caiman (2) (5). In 1990, a captive breeding and reintroduction programme was initiated in Bolivia (5). As well as enforcing existing laws, captive breeding and reintroduction programmes need to be implemented in other countries to assist the recovery of this remarkable reptile (2).

There have been claims that the caimans consume large quantities of commericial fishes, having a negative impact on local fishermen, but analysis of stomach contents in one study indicated only small volumes of such fish are eaten at any one time. This does not support the fishermen's claims, and the Black Caimans probably do not significantly affect local fishing.

The Black Caiman will on occasion prey on domestic animals, and there have also been attacks on humans. (Britton 1999, Da Silveira and Magnusson 1999).

As the largest predator in the ecosystem, the Black Caiman may play the role of a keystone species and help to maintain the structure of its ecosystem. Important activities may include nutrient cycling and the selective predation of certain fish species. Its disappearance from the Amazon would leave a large ecological gap, with adverse effects for its habitats.

If populations recover sufficiently, the Black Caiman could provide economic benefits through controlled hunting for meat. This would give local peoples more incentive to protect the species (Thorbjarnarson 1998, Thorbjarnarson 1999).