CONSERVATION:
This species has actually benefited from commercial utilisation and over-hunting of other species within its range (Crocodylus acutus, C. intermedius and Melanosuchus niger), taking over habitat from which it would otherwise have been out-competed by healthy populations. The skin of C. crocodilus is not ideally suited to tanning, as the ventral scales contain well-developed osteoderms. Only the lateral flanks provide skin of an acceptable quality for tanning. Hunting pressures remained relatively low, therefore, until populations of the sympatric crocodilian species became depleted in the 1950s, when hunting of C. crocodilus intensified. The numbers of caimans harvested since then has been huge, and they currently supply the vast majority of the hide market in America. Leather from this species is often passed off as Alligator mississippiensis or other species.
Despite pressure from hunting and also collection for the pet trade, however, existing surveys suggest that populations are in relatively good condition in most areas (e.g Venezuela). This seems to reflect the adaptability of the species, its reproductive potential, and the increase in available habitat through the removal of competing species and an increase in man-made water bodies (e.g Brazilian Panatal, Colombia, Venezuela). However, it is these factors which make it difficult to determine the overall status of the species, as populations are faring less well in other areas - surveys reveal severe depletion in El Salvador. More up to date surveys are required for clarification, and to examine the interactions between the different subspecies. Further taxonomic work would make control measures easier to implement, as currently identification of different subspecies can be difficult. The major threat to this species and its subspecies is currently illegal hunting. Smuggling rings operating through Thailand and Singapore are extremely damaging to individual populations, and greater control measures and more effective legislation are needed.
The subspecies C. c. apaporiensis is under severe threat in Colombia. Feral populations of C. crocodilus are creating problems for other species of crocodilians and native wildlife, however. These populations have become established in three countries. The introduced population in Cuba is thought to have been primarily responsibly for the dramatic decline and probable disappearance of Crocodylus rhombifer from the Isle of Pines.
Sustainable use programs are well developed in several countries. Most of these rely upon regular cropping of wild populations. The long-term effects of this cropping need to be investigated. The reproductive potential of this species makes properly controlled sustainable yield programs look promising. Farming and ranching programs, while they exist, may be uneconomical in the long run, given the value of the hide and the number of animals which need to be culled in order to produce a profitable amount of hide.
MORE INFORMATION:
For more information on distribution and conservation issues for this species,see the CSG Action Plan resource.
SIGNIFICANT REFERENCES:
Gorzula, S & Seijas, AE (1989). The common caiman. In: Crocodiles. Their Ecology, Management and Conservation. A Special Publication of the IUCN/SSC Crocodile Specialist Group. IUCN, Gland, Switzerland. pp. 44-61
Medem, F (1981). Los Crocodylia de Sur America. Vol.1 Los Crocodylia de Colombia. Colciencias, Bogota. pp. 354
Oubotor, PE & Nanhoe, LMR (1988). Habitat selection and migration of Caiman crocodilus crocodilus in a swamp and swamp-forest in northern Suriname. J. Herpetol. 22: 283-294
Staten, MA & Dixon, JR (1977). Breeding biology of the spectacled caiman, Caiman crocodilus crocodilus, in the Venezuelan Llanos. Fish and Wildlife Service, Wildlife Research Report 5. United States Dept. of the Interior, Washington, D.C.
Thorbjarnarson, JB (1994). Reproductive ecology of the spectacled caiman (Caiman crocodilus) in the Venezuelan llanos. Copeia 1994(4): 907-919
Magnusson, WE, Da Silva, EV & Lima, AP (1987). Diets of Amazonian crocodilians. J. Herpetol. 21(2): 85-95
Velasco, A, Trejo, V & Zapata, I (1994). Stomach contents of Caiman crocodilus from the Orinoco delta of Venezuela. Crocodile Specialist Group Newsletter 13(3): 20-21