Crocodylus acutus

Common names: American crocodile, Cocodrilo, Lagarto, Caiman de la costa, Caimán aguja Range: Belize, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Nicaragua, Mexico, Panama, Peru, United States, Venezuela

CITES: Appendix I
CSG Action Plan: Availability of Survey Data – Poor
Need for Wild Population Recovery – High
Potential for Sustainable Management – Moderate
1996 IUCN Red List: VU Vulnerable. Criteria A.1.a.c. inferred decline >20% in 3 generations, inferred from reduction in extent of occurrence.
Principal threats: Illegal hunting, habitat destruction.

Ecology and natural history

The American crocodile is the second most widely distributed of the New World crocodiles, ranging from the southern tip of Florida, both the Atlantic and Pacific coasts of southern Mexico, Central America, and northern South America, as well as the Caribbean islands of Cuba, Jamaica, and Hispaniola. The habitat of the American crocodile consists largely of freshwater or brackish water coastal habitats such as the saltwater sections of rivers, coastal lagoons, and mangrove swamps. However, populations are known from freshwater areas located well inland, including a number of reservoirs. Also, one of the largest known populations is in Lago Enriquillo, a landlocked hypersaline lake situated 40m below sea level in the arid southwestern Dominican Republic.

The American crocodile is a relatively large species, with males having maximum lengths of 5–6m range, although some 7m individuals have been reported (Schmidt 1924, Medem 1981). This species is characterized by the most reduced and irregular dorsal armour (osteoderms) of any crocodilian (Ross and Mayer 1983).

Crocodylus acutus is one of the most adaptable crocodilians in terms of nesting ecology. Throughout most of its range the American crocodile is a hole-nesting species. However, in areas where access to well drained nesting beaches is limited, females will form mound-type nests (Campbell 1972a, Kushlan and Mazzotti 1989b). Clutch size is typically in the 30–60 range, although in some populations mean clutch size is in the low 20s (Thorbjarnarson 1989). As with most hole nesting species, C. acutus nests during the annual dry season with eggs hatching around the beginning of the annual rainy period (Thorbjarnarson 1989). Extensive nest protection has not been reported in most areas (although see Dugan et al. 1981).

A number of studies have examined aspects of the population ecology of the species in Florida (Kushlan and Mazzotti 1989 a and b, Ogden 1978, Moler 1991, Moler and Abercrombie 1992), Haiti (Thorbjarnarson 1988a), and Venezuela (Seijas 1988). Behavioral studies in captivity have been carried out and published by Garrick and Lang (1977). Much of the published information on the ecology of this species prior to 1988 was summarized by Thorbjarnarson (1989).

Conservation and status

The American crocodile is found in 17 countries in the northern Neotropics. This species produces a commercially valuable hide and the principal reason for past declines in population size can be attributed to the extensive commercial overexploitation that occurred from the 1930s into the 1960s. Current threats are habitat destruction and in some areas continued hunting. The collection of adult breeders to stock farms could become a serious problem in some countries if not closely regulated by the appropriate management authorities.

At present, the overall quality of survey data is poor. No recent surveys are available from El Salvador, Guatemala, Panama, Colombia, Ecuador and Peru. In 11 countries some survey data are available, and in one (the United States) widespread survey work has been conducted.

In Mexico, populations remain in the Santiago river of Nayarit and Jalisco (Casas Andreau 1990, 1994) although they may be threatened by hydroelectric construction. Some populations in Sinaloa, Yucatan and Veracruz are reported to be greatly depleted or eliminated. Populations are also reported to be greatly depleted in Guatemala (Enrique Fernandez, pers. comm.). A private program to maintain a captive breeding stock for conservation purposes is underway. In Honduras, most of the major rivers of the Atlantic drainage support small populations, although these may be depleted (King, Espinal and Cerrato 1990, King and Cerrato 1990). A population in El Cajon reservoir is negatively affected by changing water levels and human interference (Rodriguez 1990). Surveys in Nicaragua by King, Ross, Morales and Gutierrez (1994) report C. acutus to be very rare but still present in the Atlantic drainage, and several viable populations were identified on the Pacific coast (Estero Real, las Salinas) and near Managua. Incidental illegal take in association with the legal caiman harvest is a problem. In Costa Rica, a viable population of over 300 individuals is reported from the Rio Grande de Tarcoles (Sasa and Chaves 1992) and another of around 35 individuals in Estero Roto (Chaves 1993). Crocodiles are also known to be present at Playa Nancite (Plotkin and Zanella 1994) and are rare but present in the major Atlantic rivers. The situation in Colombia is poorly known, but major populations on the Atlantic coast and Magdelena river drainage are thought to be severely depleted or extirpated. A small population is reported to persist in Bahia Portete (Abadia 1995). Farms in Colombia are maintaining stock for captive breeding. In Ecuador, coastal mangrove destruction for the construction of shrimp aquaculture facilities is removing crocodile habitat. Small numbers of C. acutus are being held in captivity for future breeding (Forestieri 1994). The species reaches its southern limit in the vicinity of Tumbes in northeastern Peru. Small populations are reported from the estuaries and mangroves of the Tumbes, Mango, Tigre, Ucumares and Chica rivers (Vasquez and Pickens 1995).

In Venezuela, an active program of surveys and restocking from ranched stock has been conducted in Falcon province in the north east of the country (Arteaga 1993) and in Aragua province (Lander and Bisbal 1994). Comparative surveys between 1986 and 1993 suggest that populations in several locations are stable or growing as a result of protection and restocking, although residual problems of illegal killing for medicinal products is reported (Arteaga 1994). The small population in south Florida, USA, is steadily growing with a record 34 nests in 1993 (Anon. 1993a, Moler 1991). The population of C. acutus in Lago Enriquillo, Dominican Republic, has received intense study and conservation action since 1992. This population is thought to have declined to about a third of its estimated size in 1980 of 300–600 due to illegal killing and a decrease in fish resources from overfishing. A program of protection was developed by the Department of Wildlife D.R., and the population is now thought to be stable at around 200 individuals. A program to establish a genetic reserve of 130 juveniles transfered to the Dominican National Zoo was unsuccessful (Schubert 1994, Schubert and Santana 1996). Thorbjarnarson (1989) reported on the population in Etang Sumatre in Haiti and some other coastal locations. Recent informal surveys indicate this population is greatly reduced (A. Schubert in litt. 1996).

Surveys in Cuba conducted for the Cuban crocodile also reported substantial populations of C. acutus in the Zapata swamp (Ramos et al. 1994) and populations on Isla de Juventud, Canarreos Archipelago, Jobabo and Cheve lagoon and Birama swamp are reported to be robust (Ottenwalder and Ross 1991). Platt (1994b) summarizes localities of C. acutus in Belize including six mainland localities and 11 offshore Cays. Platt provides quantitative survey data for Turneffe Atoll indicating a population of at least 50 non-hatchling individuals. Meerman (1992) reports surveys in the Shipstern area. Belize, with Cuba, may be one of the remaining strongholds for the species, although some reduction of available habitat by coastal development is evident in both countries.

A majority of countries (eight) have management programs based on complete protection, but only a few have enforced this legislation. Two countries (El Salvador and Haiti) have no management programs whatsoever. In five countries, farming of C. acutus has begun (farming is also being planned in Jamaica), and in Cuba ranching is also conducted.

As American crocodiles produce a commercially valuable hide, sustainable utilization programs based on ranching and farming are feasible. However, the development of management programs based on sustainable utilization must be approached on a country-by- country basis and be directly linked to the health of wild populations.

Priority projects

High priority

Status and distribution in Colombia: Since the work of Medem (1983), very little work has been done on crocodilians in Colombia. While populations were widespread along both the Caribbean (particularly in the Magdalena River basin) and Pacific coasts, they suffered heavily from commercial hide hunting. Surveys are urgently needed to determine the status of current populations as a first step towards establishing a management for this species, in association with the development of captive breeding programs.

Establishment of management and protection for breeding areas in the offshore cays of Cuba and Belize: These two areas are emerging as the largest remaining concentrations of the species with the least potential for human conflict. Securing these important areas for conservation and possible sustainable use is a priority.

Status and ecology in Costa Rica: Reports indicate the presence of healthy populations of C. acutus in Costa Rica, particularly in the Tempisque and Tarcoles River. Because of its excellent institutional infrastructure, Costa Rica would be an ideal site to conduct population research on this species for management and conservation purposes.

Status and distribution in Mexico: Although some surveys are being conducted along the western coast in Jalisco, no coordinated effort is being made to assess the status of C. acutus in Mexico. With the developing interest in managing the species on a sustainable basis, more extensive survey work will be necessary. Of related interest will be surveys of the status of the introduced Crocodylus moreletii populations along the Pacific coast and an assessment of the threat that they represent to the native C. acutus.

Moderate priority

Status and distribution in Panama, Ecuador, El Salvador, Guatemala, Honduras, Haiti and Peru: Existing information suggests these are either peripheral range states or already depleted. Nevertheless, basic surveys as a preliminary to conservation action are needed.

Development of a management program in Jamaica: American crocodiles are reasonably abundant in a number of areas along Jamaica’s southern coast. Recent interest has developed in farming this species, but a comprehensive management plan needs to be developed that addresses the well-being of wild crocodile populations. The relative advantages of farming and ranching should be addressed, and a crocodile population monitoring program established.

Restocking and conservation in Venezuela: Continuation of the existing conservation and restocking program in Falcon and Aragua provinces.

American crocodile, Crocodylus acutus, USA. Photo by R. Godshalk.