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Crocodiles
Crocodilians: The Top Five
Across our planet, there are 23 species of crocodiles and alligators (collectively termed “crocodilians”), the top predators of tropical and subtropical wetland ecosystems. Historical accounts suggest that many crocodilians were commonly seen along riverbanks or in lakes in many parts of South and Central America, the Caribbean, Africa and Asia. However, beginning in the later half of the 19th century, it became popular to have leather products made from the skin of alligators and crocodiles, and many species were hunted to make shoes and handbags. After World War II, this commercial hunting intensified, and by the 1960s and 1970s some crocodilians were brought to the brink of extinction.
Today, most of the lawless killing of crocodilians has been halted and replaced with managed harvests do not threaten extinction. However, some species have not recovered from the double-whammy of widespread commercial killing and habitat loss as a result of growing human populations and increased agricultural expansion. It is these species that remain critically endangered, and which are the focus of WCS conservation activities. In particular, we are focusing our work on the five most threatened species: the Chinese alligator, and the Philippine, Siamese, Orinoco and the Cuban crocodiles.
Chinese Alligator
 Known locally as the “muddy dragon,” the Chinese alligator is teetering on the edge of extinction in the wild. While the Chinese government has successfully developed a captive breeding program for the alligator, the wild population has continued a steady slide towards extinction, and now numbers less than 130 individuals. Unlike its abundant American cousin, Chinese alligators, found only in a tiny area in the lower Yangtze valley, are refugees in a landscape where extensive natural wetlands have been converted almost entirely to rice paddies. To save these animals, WCS biologists are working with Chinese wildlife authorities to protect and restore remaining wetlands. New alligator populations will be established by releasing animals currently being reared in captivity. A trial alligator reintroduction program began in April 2003 with the release of three animals, a project being carried out by WCS, the East China Normal University, and the Anhui Province Forestry Department. In the US, WCS is also coordinating the captive breeding of Chinese Alligators as part of the American Zoo and Aquarium Association's Species Survival Programs.
Philippine Crocodile
Possibly even more endangered than the Chinese alligator, the Philippine crocodile hovers at no more than a few hundred individuals in the wild. Following World War II, populations crashed due to increased hunting for its skin, coupled with habitat loss. WCS has been supporting efforts to find out where these endangered crocs still live, and a DNA study to determine if crocodiles from different islands in the Philippine archipelago are genetically distinct from one another. The highlight of this work has been the discovery of three previously unknown populations of the Philippine crocodile, two in the remote foothills of the Sierra Madre Mountains on Luzon and another on Mindanao Island. There is at least one breeding pair of crocodiles in each of these areas. Although additional surveys are needed in order to obtain reliable estimates of the population size, these results underscore the critical status of the animals in the wild.
Siamese Crocodiles
 Until recently, scientists believed that the Siamese crocodile may be extinct in the wild, since the last known population in Thailand had vanished in the 1980s. However, at that time very little was known about crocodiles in the war-torn region of Vietnam, Laos and Cambodia. In 1998, WCS began to survey these parts of Southeast Asia to see if isolated populations still existed. We found that the crocs are all but gone from Vietnam, but still survive in remote areas of Laos and Cambodia. Then in 2001, WCS received good news from Thailand when a remote camera trap set for tigers turned up a photograph of a single Siamese crocodile lumbering along a riverbank. Where’s there’s one, there must be more…., and since that time we are following up on reports of crocodiles in several other protected areas in Thailand. Working with a wide spectrum of governmental and private conservation groups, WCS is now taking the lead to develop a regional conservation program for the critically endangered species.
Orinoco Crocodile
 Reaching lengths of up to 20 feet, the Orinoco crocodile is the largest predator on the South American continent. To save these amazing creatures from extinction, WCS and a team of Venezuelans have breed and released more than 3,000 young crocodiles back into the wild. Some have now reached maturity and started laying eggs. Andres Eloy Seijas, during nearly a decade of research supported by WCS, is now a professor at the UNELLEZ University in the central Venezuelan plains, or “Llanos”. Today, Dr Seijas and WCS are working to save the largest remaining group of Orinoco crocodiles in the Cojedes River in Venezuela, a population under severe threat from pollution, agricultural expansion and damming.
Cuban Crocodile
 The Cuban crocodile is a relic from the Pleistocene era, when it spent much of its time feeding on the now-extinct giant ground sloths and other mammals that once roamed the landscape. Today, these aggressive crocs are found only in Cuba’s Zapata Swamp, and the Lanier Swamp on the Isle of Pines. The crocs are now threatened by human encroachment, and hybridization with the American crocodile, which shares its habitat. Beginning in 2002, WCS has supported the work of Cuban crocodile biologists who have been working with this species for over 25 years.
Crocodiles- Managing the consequences of Success
While some crocodilians remain critically endangered, others have responded well to the cessation of hunting and have rebounded. The key to the success of these species has not only been the reduction of the number of crocodiles killed by people, but also the presence of good quality habitat. In some areas, crocodiles are again becoming numerous, and in the case of larger species, representing an increasing threat to people and their livestock. Dealing with the consequences of recovering crocodilian populations will be an important part of future management efforts for these species, and WCS is carrying out projects on two species, the Black caiman and the American crocodile, that fall into this category.
 The Black caiman is the largest predator in the Amazon Basin. Favoring floodplain lake habitats, the black caiman was hunted mercilessly beginning the 1940s, and as a consequence was rarely seen. However, in some areas, particularly in expanses of sparsely populated flooded forest habitats, black caiman are now making a comeback. Since 1995 WCS has been working in the Mamirauá reserve of northwestern Brazil to learn more about this elusive animal, its interactions with people, and alternatives to insure a peaceful coexistence of the two species. To find out more about the Black Caiman's habitat visit www.floodedforest.com.
 The American crocodile has a definite preference for coastal areas, and is found in a variety of habitats from southern Florida to northern Peru. While populations in many areas remain low, in some regions the species is making a recovery. Over the last 20 years WCS biologist Dr. John Thorbjarnarson has worked with this species in 9 different countries, and is currently developing a collaborative program with Cuban scientists to study what is probably the largest American crocodile population, in the delta of the Cauto River in southern Cuba. The results of this work will assist with the development of management plans for crocodiles in Cuba as well as in other parts of the species range. In 2002 WCS, together with the University of Florida that brought together experts from around the species’ range to identify conservation priorities for American crocodiles in the new millennium.
Recently, WCS has begun to address the issue of crocodile bushmeat trade in Central Africa, and has undertaken surveys for Nile, slender-snouted and dwarf crocodile in Congo and Gabon. Ecological research, combined with studies of hunting and marketing of crocodiles will be used to develop management strategies to protect these species.
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