| Important synonyms: Caiman sclerops
Common names: Common caiman, spectacled caiman, baba, babilla (Venezuela, Colombia), guajipal (Nicaragua), jacaré tinga, jacaré, lagarto blanco, cocodrilo, ocoroche, cascarudo, cachirre, tulisio Range: Brazil, Colombia, Costa Rica, Ecuador, El Salvador, Guyana, French Guiana, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname, Trinidad and Tobago, Venezuela (introduced: Cuba, Puerto Rico, United States) Revised by Eduardo Espinosa |
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Conservation overview
CITES: Appendix II, except C. crocodilus apaporiensis –
Appendix I
CSG Action Plan:
Availability of Survey Data – Adequate
Need for Wild Population Recovery – Low
Potential for Sustainable Management – Highest
1996 IUCN Red List: Not Listed (LRlc Lower Risk, least
concern, probably numbers in the millions, widely
distributed throughout range, although locally depleted
or extirpated in some localities.)
Principal threats: Illegal hunting, habitat loss.
Ecology and natural history
The common caiman is the most widely distributed of the
New World crocodilians, ranging from southern Mexico
to Peru and Brazil. It is also the most geographically
variable species with four or five subspecies generally
being recognized as follows (Medem 1981, King and
Burke 1989):
• C. c. crocodilus, the nominate form, distributed
throughout the Orinoco drainage and llanos in
Venezuela and the Amazon drainage from Colombia
through Brazil north and east of Bolivia to Peru.
• C. c. fuscus, Atlantic coastal drainages of Colombia
(including the Magdelena River) and into western
Venezuela.
• C. c. chiapasius, Central America, Mexico to pacific
Colombia and possibly Ecuador and to the Gulf of
Uruba. Some authorities consider this identical to C. c.
fuscus.
• C. c. apaporiensis, a narrower snouted form restricted
to the upper Apaporis river of Colombia although a
cline of narrow snouted caimans may be present across
Colombia and the Venezuelan llanos (Ayarzagüena
1984, Gorzula 1994)
• C. c. yacare (= C. yacare), the southern form, is
distributed from southern Brazil through Bolivia,
Paraguay, and Argentina. It is variously considered to
be a subspecies or a full species by different workers. In
this Action Plan the most recent taxonomic review is
followed (King and Burke 1989), which classifies
C. yacare as a full species. The most recent
morphological (Busack and Pandya in litt.) and DNA
analyses (Amato and Gatesby 1994) suggest that
C. c. fuscus and C. c. chiapasius form one natural group
and C. c. crocodilus and C. c. yacare another.
The common caiman is a small to medium sized
crocodilian (maximum length in males ca. 2.8m), that is
extremely adaptable in terms of habitat requirements. At
one time this species may have been relegated to a much
smaller ecological niche, but with the extensive commercial
overharvesting of the larger sympatric species of
crocodilians (C. acutus, C. intermedius, M. niger), the
common caiman now inhabits virtually every type of low
altitude wetland habitat in the Neotropics.
A great deal of biological investigation has been carried out on this species, particularly in seasonal savanna habitats. Relatively less is known about its behavior and ecology in forested or swamp habitats (Ouboter and Nanhoe 1988, Ouboter 1996). Much of the earlier ecological information for this species is summarized in Gorzula and Seijas (1989). Female common caiman reach sexual maturity at about 120 cm total length and lay an average of 20–40 eggs in a mound nest, usually during the annual wet season.
Conservation and status
Owing to the extensive development of ventral osteoderms
(boney inclusions), caiman belly skins are of inferior
commercial quality compared to those of crocodiles and
the American alligator, and usually only the lateral flank
region is used. Because of the low value of the hide,
caiman exploitation did not begin until the 1950s
when stocks of the more valuable classic crocodiles had
dwindled. However, since the 1950s, millions of caiman
have been harvested, and Caiman crocodilus and C. yacare
continue to supply the vast majority of skins on the
market. Caiman appear to have been quite resilient to
commercial hunting for a number of reasons, particularly
because they reproduce at a relatively small size, and
hunting in many areas appears to have concentrated on
the larger adult males. Another important factor has been
the near extirpation of larger, sympatric species of
crocodilians of greater commercial value. Caiman now
occupy habitats that were formerly dominated by
Melanosuchus niger, Crocodylus intermedius and C. acutus
(Magnusson 1982, Thorbjarnarson in press). Furthermore,
in areas such as the llanos of Venezuela and Colombia and
the Brazilian Pantanal, the proliferation of man-made
water bodies (e.g., borrow-pits) has increased the carrying
capacity for caiman populations in these habitats. Although
they may be locally depleted, present populations may be
larger than they were historically. The ecological
adaptability of the common caiman is evident in the
United States (Florida and Puerto Rico) and Cuba, where
introduced caiman populations are established and
impossible to eradicate. The Cuban population is alleged
to have contributed to the extirpation of Crocodylus
rhombifer from the Lanier Swamp on the Isle of Pines. In
Guatemala, a population of Caiman crocodilius crocodilus
is reported to have been introduced, allegedly from
Venezuela as hatchlings (R. Jenkins from O. Lara pers
comm.).
After the completion of recent new surveys of caimans
in Nicaragua (King, Ross, Morales and Gutierrez 1994)
Paraguay (King, Aquino, Scott and Palacios 1994) and
Colombia (Barahona et al. 1996a and b), relatively good
survey data are available in nine of the 17 countries in
which Caiman crocodilus is found. However, surveys are
still being planned in several Central American and
northern South American nations. In all the countries
surveyed, densities and inferred numbers are highly variable
due to seasonal aggregation at times of low water, and
dispersal at high water. In general, densities of 5–50+
individuals per kilometer of standard survey are observed,
with lower densities 0.5–5.0/km in areas of heavy hunting
(see King, Aquino, Scott and Palacio 1994 for summary).
Little information is available for the northern end of the
species range in Mexico, El Salvador and Guatemala.
Also, few surveys have been done on the introduced
populations in the United States (Florida and Puerto
Rico) and Cuba.
Although the available information is sketchy in many
areas, caiman populations appear to be doing relatively
well in most countries. Only in El Salvador are populations
suspected to be severely depleted, and very little recent
information is available for this country. In many areas
where recent surveys have been conducted (e.g. Honduras,
Costa Rica, Nicaragua, Venezuela), the species does not
appear to be significantly depleted although it does face an
array of problems such as illegal hunting or habitat
destruction. In areas heavily frequented by hunters the
larger size classes may be rare. Local extirpation adjacent
to urban areas and intensive agriculture is observed, but
wherever their habitat remains intact, this adaptable small
crocodilian appears to remain abundant. Where harvest
regulations and use programs are enforced on a sustainable
basis, populations are reported to be stable or increasing
(e.g. Velasco and Ayarzagüena 1992, Gorzula and Pilgrim
1992).
Despite the overall good status of this species, urgent conservation action is needed for Caiman crocodilus apaporiensis. This virtually unknown subspecies has a very restricted range in the Colombian Amazon, and surveys are needed to determine its population status.
A number of Latin American nations have developed sustainable management programs for the common caiman. Because the species produces a lower value hide, some of these management schemes are based on the cropping of wild populations. By far the largest such program is in Venezuela and is based on the harvest of adult males. Other cropping programs exist in Guyana, Nicaragua, and formerly in Honduras. However, in recent years a number of countries have begun to develop ranching and farming programs. A major program in Columbia that focuses on captive breeding produces between 300,000 and 450,000 skins per year (Jenkins et al. 1994). Brazil is also developing extensive captive breeding programs with over 100 facilities established. There is also increasing interest in developing ranching programs, particularly in the Pantanal region. Because of the low relative value of caiman hides, the economic viability of these activities has been questioned (Magnusson 1984). This species, along with the yacaré caiman, is currently supplying approximately three-quarters of the legal crocodilian skins in international trade.
Since 1983, Venezuela has operated the largest cropping
program for any species of crocodilian based on controlled
hunting by private landowners. The system allows
private landowners to harvest up to 20% of caiman above
180cm total length each year, effectively restricting the
harvest to adult males. Quotas were initially established
based on census data from each property, provided by
licensed surveyors engaged by the property owners. Annual
exports average 70,000–90,000 skins per year. The program
also includes a rigorous system of licensing of producers
and processors, centralized inspection and storage of
skins and careful monitoring of tanneries and exports.
However, annual evaluations of the program and
independent surveys in 1991–92 suggested overexploitation
in some areas (Velasco and Ayarzagüena 1992). In 1994,
a new method to assign the harvest quotas was established
and the annual export quota was reduced to 30,000 skins.
Currently, quotas are assigned on the basis of regional
surveys, ecological region and the size of the property,
and restricted to 15% of the class IV (180 cm length)
individuals (Velasco et al. 1995). The values generated are
compared with the regional average values derived
independently by the management authority – CITES
study, and adjustments to the estimated population, and
harvest quota, calculated (de Sola and Velasco 1994). The
program offers an unparalleled opportunity to establish
experimental harvesting regimes in conjunction with
population studies. In 1996, Venezuela instituted a
complete halt to caiman harvesting to allow detailed
analysis of the effects on populations (Quero and Velasco
1995). Harvest re-opened in 1997 based on the results
of extensive re-evaluation of the populations in the
field. The Orinoco Delta region has been recently
incorporated into a program of exploitation of caiman
based on a recent study (Velasco et al. 1994), which
showed that only 3% of the individuals in this region are
harvestable animals.
Illegal trade in caiman skins has been, and continues to
be, a problem. Legal production of caiman skins now
numbers in excess of half a million skins a year (Collins
1995). Improved enforcement and CITES implementation,
as well as reduced demand during 1990–1994, appears to
have reduced the flow of illegal skins. However, significant
illegal shipments continue to be interdicted. Meeting the
world demand from legal, sustainable production,
improved coordination for CITES implementation in the
region, and the requirement to tag all crocodilian skins
(CITES Resolution Conference 9.22) are expected to
further curtail illegal trade. However, illegal trade
undermines the economic viability and regulatory capacity
of sustainable use programs in the region. Continued
enforcement within Latin America, and coordinated action
with the major consuming countries are needed to eliminate
illegal trade in caiman skins.
Priority projects
High priority
Survey of Apaporis River caiman in Colombia: Caiman crocodilus apaporiensis is thought to be present only in the upper and middle Apaporis River and some adjacent areas in southern Colombia. No recent information on the status of these populations is available. Surveys are urgently needed to determine the present status of this unusual form of the common caiman.
Control of illegal trade in caiman skins: Substantial
quantities of illegal caiman skins continue to pass from
South America to consuming and manufacturing
countries. The general success of CITES measures to
control trade indicate that full enforcement of CITES will
be an effective way to control this illegal trade. This
requires coordinated action in both producing and
consuming countries. In some cases existing national
legislation is an impediment to CITES implementation.
For example the ban on wildlife exports from Brazil
impedes the development of sustainable ranching
programs in that country; and in Thailand inadequate
inspection, documentation and enforcement makes
assessment of the caiman trade impossible. Inconsistencies
between international CITES regulations and more
stringent national regulations in the USA remain a serious
impediment to the orderly development of international
trade controls. Allegations of extensive illegal trade from
Brazil and Colombia remain undocumented but persistent.
Considerable progress has been made in these areas. CITES
implementation would be facilitated by regular
consultation, exchange of intelligence, technical
assistance and cooperation between CITES management
authorities within Latin America and with consuming
countries. The CSG has a major role to play in promoting
these activities.
Moderate priority
Implementation of caiman sustainable management programs: Because caiman mature relatively fast and are extremely adaptable in terms of habitat requirements, they have a very high potential for inclusion in sustainable management programs. Support for developing such programs throughout Latin American is needed. Initial work should center on conducting population surveys and making recommendations tailored to the type of management being considered (cropping, ranching).
Taxonomic study of the caiman species complex: The relationships among the caiman species complex are still poorly understood. This has created conservation problems due to the inability to recognize subspecific taxa that may differ in trade restrictions. Investigation of the southern C. crocodilus - C. yacare relationships is underway but remains inconclusive. In the near future such research should include the use of genetic tools, such as DNA analysis, to determine phylogenetic relationships within the Caiman species complex. This work needs to be expanded to include northern South America and Central America.
Long-term ecological studies in the Venezuelan llanos: The Venezuelan llanos has been the site of a considerable amount of research on the ecology of the common caiman. It also is the site of a large harvest program, and offers unequaled opportunities for the investigation of a number of aspects of the population biology of this species. This work is done in conjunction with the monitoring of harvest effects in order to improve our ability to manage wild populations of this species. Although reductions in hunting quotas may affect the funding of the management program, the continuous monitoring of the population must be seen as a top priority.
Common caiman, Caiman crocodilus, in Venezuela. This widespread
and abundant species has several subspecies and successfully
supports international trade of over 500,000 skins annually from
sustainable programs. Photo by R. Godshalk.