Promise for the Survival of the Orinoco Crocodile: a strong commitment from the private sector in Venezuela

In 1800 the German scientist Alexander von Humboldt spent four months exploring the then wild and uninhabited Orinoco. He traveled 1,725 miles of the vast northern South American river's basin. Humboldt wrote vivid accounts of his encounters with huge numbers of crocodiles, many of which exceeded 6 meters (20 feet) in length. We now realize these were Orinoco crocodiles (Crocodylus intermedius), a large fresh water crocodilian endemic to the middle and lower reaches of the Orinoco River basin of Venezuela and eastern Columbia. The species is completely restricted to this river and former records of individuals from Trinidad and Grenada are of vagrants displaced into the sea during floods. The Orinoco crocodile was very common up to the mid-1930s, but its large size and a lack of osteoderms in the belly skin resulted in heavy exploration of their hides and its entire population is now greatly depleted. While in former times males were reported which exceeded 7 meters, today individuals over 5 meters are rare. The species is considered to be endangered throughout its range, and at this time fewer than 1,500 non-hatchlings survive in the wild. Some estimate that the wild population may be as low as 250 adults and declines and fragmentation of the population continues. Generally the biology of Orinoco crocodiles is poorly known in that the populations were decimated prior to any detailed studies.   Problems facing the survival of this species for the most part have not been addressed, and the species is on the verge of extinction in Columbia where the primordial population probably was in the hundreds of thousands. In Venezuela the prospects for survival are better, and an active conservation and management program is in place. Some of the key components of the species survival plan center around captive breeding, and head-starting/release programs financed locally by the private sector.   Here I give a brief overview of the species biology and its conservation status and then discuss what I believe to be an exciting home spun conservation addenda. Biology of the Orinoco crocodile Orinaco Crocodile (Crocodylus intermedius) Description: The Orinoco crocodile is one of the larger of the crocodilian species although today's large adults range from only 3.5 to 5 meters. The head and snout is relatively long and narrow and similar to the African slender-snouted crocodile (C. cataphractus). The specific epithet intermedius refers to this narrow snout which is between that of most Crocodylus and the narrow-snouted Gavialidae. This narrow snout is apparently an adaption to its fish eating habits. Unlike the closely related, and primary estuarine American crocodile (C. acutus), the only other species of Crocodylus in South America, the dorsal armor is symmetrical. Dorsal color variation ranges from individuals with grayish green bodies with dark blotches to one which are uniformly dark gray. The most common coloration is a light tan body with scattered dark areas. The dark areas often form interrupted diagonal crossbands which are most evident on the tail. The ventral surface is a uniform white. The dental formula is 5 pre-maxillary; 14 maxillary; 15 mandibular. No geographic variation is reported. Females are smaller than males and have a maximum size of about 3.45 meters. Habitat: This is a species of freshwater rivers of Llanos savannas. The Llanos covers a large area, extending across approximately 250,000 km2 in Columbia and 265,000 km2 in Venezuela. For Venezuela this represents about 1/3 of the country. The Llanos is effectively cut off from the Caribbean by a long line of mountains called the "Cordillera de la Costa" that parallels the coast of northern Venezuela. During the Pliocene, the area which is now occupied by the Llanos was a delta type environment isolated from the rest of South America by the Andies, the Coastal Cordillera and the older Guayana highlands. It was apparently this isolation which assisted the evolution of an endemic crocodile. Due to poor drainage water may cover up to 80 to 90% of the land, greatly increasing the availability of tributaries that can be used by the crocodiles, allowing the animals escape from strong river currents, and providing nearly unlimited dispersal opportunities. The flooding occurs quickly and remains for some months after the rains stop. The Orinoco carries massive flows from the extensive rainforest that occur in southern portion of the watershed and the entire eastern slope of the northern Andies. The increased flow of the Orinoco acts like a dike holding back the flow of tributaries and spilling water over the plains of the low Llanos. In the dry season (mid October through late April) water levels drop and much of the aquatic Llanos habitat disappears. At these times Orinoco crocodiles move to wide and deep portions of large rivers or retreat into self constructed burrows along stretches of rivers where pools of water remain. In some areas they aestivate during the dry season. As the waters recede individuals often move overland in search of permanent water. Crocodile hide trade at San Ferando; ca. 1940s   Formerly Orinoco crocodiles occurred in a wider variety of habitats and even lived in the tropical forest streams in the foothills of the Andes. For the most part the species is now restricted to the large meandering rivers crossing vast savannas of the Llanos. Large oxbow lakes and elbows, resulting from changing river courses are a common feature in some areas. The species also has been reported from reservoirs, but because of human contact reservoirs do not support viable populations. Juveniles seek shelter in quiet water with abundant aquatic vegetation. Food: These crocodiles are primary fish eaters, but they also eat mammals and birds coming to water. Fish and other prey become condensed and are easily captured during the dry season. Captive animals, including large adults, matained with various species of side-necked turtles show no interest in turtles as food items. There are a few unsubstantiated reports of humans being taken. Larger territorial males can be quite aggressive, but local people have no hesitation in swimming in waters inhabited by these crocodiles and one instance of a person swimming in a pond with a number of large captives was uneventful. Young animals under 1 meter feed mainly on small fish, insects, crabs, snails and other invertebrates. Reproductive Biology: Males are territorial. Females lay eggs in nests dug in sand banks and their reproductive cycle corresponds with the dry season when river bank nesting sites are exposed. Clutch size is large and ranges from 15 to 70 eggs, and most laying occurs in January/February and hatchlings emerge about 70 days after laying. Hatching usually coincides with the onset of rising waters. Hatchlings do not apparently at first enter the water voluntary and anecdotal reports suggest they are carried from the nest in the mouths of their mothers. In captivity at least both sexes also help to feed the young by bringing captured prey to the pods and dismembering it near them. Females guard the nest and protect the hatchlings for up to three years. Despite protection of the nest by the females predation rates by tegu lizards (Tupinambis) and vultures are often high. Orinaco Crocodile (Crocodylus intermedius) Decline and Existing Conservation Problems: Orinoco crocodiles were very severely depleted by a hide trade which began in the 1920s, peaked in 1933-34, and went into sharp decline by the late 1940s because of a lack of commercially exploitable populations. A minimum of over 250,000 hides were taken from the Columbia portion of the Orinoco basin between the 1930s and the mid-1940s. The populations taken in Venezuela were considerably greater, and while the records are incomplete the harvests were certainly more extensive than those in Columbia. A Venezuelan hide dealer reports that in the 1920s it was not unusual to buy 4,000 Orinoco crocodile skins in a single day. Hunting operations were expedient because of high concentrations of adults during the dry season.   Today the Orinoco crocodile is one of the most critically endangered New World crocodilians, and there has been little recovery since it received complete protection in 1968. In fact, there are no known areas where these crocodiles have recovered despite the near total collapse of the hide industry over 50 years ago. Remaining populations are relicts, and restricted to small isolated areas where human impact has been minimal. However, the recent availability of outboard motors throughout the Orinoco now makes all areas within the extensive basin accessible. Current threats to these increasingly less isolated populations are mostly illegal subsistence hunting. The teeth are prized for medical purposes and the meat used for food. The eggs are also eaten. While village subsistence hunting is obviously detrimental to the long term recovery of the species it is probably even a greater threat than realized. For example, the discovery of a unknown population of Orinoco crocodiles in southern Venezuela was reported in 1982, but within five years after its discovery it was extirpated. Juveniles are still seen for sale in local markets, although their sale is illegal.   Crocodiles are commonly killed when during their seasonal movements they enter areas adjacent to villages and ranches. People fear that they or their livestock are threatened. Commercial fishing is a problem for Orinoco crocodiles because they are attracted by struggling fish in gill nets and become entangled and drowned. Sometimes these nets span the entire width of rivers and fish and other aquatic organisms are herded into the nets from upstream. Other fishing techniques, including long lines with a hundred or more baited hooks, and the use of dynamite, also take their toll on crocodiles. Commercial use of hides of poached and incidentally taken crocs, however, is all but nonexistent. Venezuela's national guard has numerous check points throughout remote portions of the country and they are very in tuned to the enforcement of the countries' wildlife laws.   Habitat destruction in the form of deforestation, the resulting siltation, and erosion, and human land use adjacent to rivers causes problems both with seasonal water flow and the loss of nesting sites. Dam construction, irrigation and other water diversions have adversely effected some rivers in the Orinoco basin. Agriculture practices, particularly the wide scale, and uncontrolled use of DDT and herbicides have been reported to result in huge fish kills when the first rains of the season wash chemicals from fields where they concentrate during the dry season. New highway construction and road modernization throughout the Llanos has increased human access in areas which only a few decades ago were remote and seldom visited.   Additionally, predation of the young and competition by the sympartic local caiman (Caiman crocodilus) population, which apparently increased in the absence of C. intermedius is suspected of hindering recovery. Furthermore, wild adult females which have been exposed to human harassment typically do not closely guard their nests or pods of young and predation rates and survival have become low. Spectacled Caiman (Caiman crocodilus) To save a species...   In a straight forward attempt to postpone extinction in 1972 Thomas Blohm initiated a captive breeding program on his ranch in the Llanos of Venezuela. Blohm had successful reproduction in 1980 from the pair he maintained in semi-captive conditions. In the same year five Orinoco crocodiles hatch in the Crandon Park Zoo in Miami, Florida. The eggs, which were produced by captive parents, were artificially incubated, and the hatching represents the first breeding of this species in zoos. Since this time two other ranches in the Llanos have started captive breeding programs. Combined the three ranches maintain approximately 40 breeding adults in 13 individual pens. While husbandry techniques are still in development the aggregate breeding program shows signs of long term success. To date just over 360 captive bred-individuals have been head-started to lengths of about 2 meters and released into refuges and other protected sites in the Orinoco basin. Another several hundred are just months away from release. Unlike in the United States, in Venezuela private corporations contribute directly to local conservation issues. They totally develop and carry out wildlife management programs with the approval of PROFAUNA, the wildlife enforcement and policy governmental organization of Venezuela. This activity stems from well engrained land management ethics and the only compensation is local pride in successful endeavors.   In addition to the captive breeding program eggs and young have been collected from the wild. The hatchlings and young are head-started and released as part of a planned restocking program. The head-started animals are released in national parks and on private ranches where they receive some degree of protection.   I am most familiar with the captive breeding program at Agropecuaria Puerto Miranda a large ranch on the outskirts of San Fernando. The corporation which runs the ranch initiated the program and in its early years received some funding from a private donor through the Bronx Zoo. At this time the entire crocodile program on this particular ranch is being financed by the Tortoise Reserve, Inc, and because of my frequent visits to this ranch I can best report on the portion of the program developed here. The ranch has a long-term commitment to this project they have constructed and fenced in six large ponds where 20 (9 m; 11 f) adult crocs live throughout the year. A large walk in freezer holds vast stores of freshwater fish, purchased locally from fishermen during the dry season, and various dismembered parts of aged stock animals.

Most of the stock animals come from the ranch itself, but some from other ranches in the Llanos are purchased or donated. A large butchering area with tile tables and scales for weighing food are adjacent to the freezer. Pedro Azuaje, the farms manager, and the person responsible for overseeing the program, estimates his adult crocs consume 14,300 kg of food a year. A separate incubation building was constructed for the crocodile eggs. The eggs are incubated in damp sand warmed by suspended heat lamps, and the floor of the building is flooded throughout the incubation period (the dry season) to keep the humidity high and constant. The large size of the building and its high ceiling helps to reduce temperature fluctuations. The eggs are incubated at 31 C and 100% humidity. A long line of outdoor cement rearing pools are used to house the hatchlings and juveniles. The pools are constructed for easy maintenance and cleaning. Lights suspended over the pools attract insects at night and provide an important supplemental food source for the hatchlings. The farm also is involved in a head starting program for the endangered giant river side-necked turtle (Podocnemis expansa). The young turtles and crocodiles are kept in the same pools as it is believed that the combination of excrement of the turtles in the water somehow exhilarates the growth of young crocs. In that crocodiles are very messy eaters, minimally the turtles help keep the water clean by eating a1l the food scraps. The rearing pens are enclosed and screened in from the sides and above to prevent predation by local wildlife. Crocodile egg incubation (Agropecuaria Puerto Miranda - Venezuela)   A licensed veterinarian visits the facility every month. Many of the ranch hands participate in various aspects of the care of the crocodiles, but because of the versatile nature of their jobs it is difficult to state how many additional people are employed for this program. I suspect it would equal three full time jobs with any number of additional ranch hands working with them during peak periods. Because of the fact that the cost of the operation are inter-mixed with those of the river turtle head-starting program and our extensive red-footed tortoise (Geochelone carbonaria) breeding/research compound, the exact cost of the crocodile program is difficult to calculate, but is estimated to be over $30,000 a year.   The captive breeding program is not without problems. Additional pens need to be constructed, and the number of viable eggs produced each year is highly variable, suggesting that the farm's husbandry needs to be more finely tuned. Fortunately, crocodilians are long lived, and the mortality of the animals living on site in semi-captive conditions has been low. This species is not particularly aggressive, at least during the non-breeding season, and the animals sharing pools have experienced no major injuries. Still it will take a lot of random experimentation to figure out which matching of specific adults, and what mixture of sexes and size classes provides for maximum viable egg production.   Since 1992, 279 head-started individuals have been successfully released from this one farm alone, another 58 await release, and it is expected that 300 eggs will be produced during the coming nesting season. The average number of hatchlings produced each year and successfully raised to release size has increased annually, and upward trends in levels of production are expected to continue. (During this same period 10,323 head-started Podocnemis expansa from this one ranch were also released into the Orinoco). This farm has also supplied individual crocs to zoos and similar institutions, last year they shipped a pair of adults to the Dallas Aquarium in a cooperative venture to increase the overall captive breeding program. Because of the success of this farm Perran Ross, Executive Officer of the Crocodile Specialist Group, considers this farm to currently have the most effective captive breeding program in Venezuela.   Education is a key component of the program and each year well over a thousand school children visit the farm and learn about the crocodiles and other wildlife of the Llianos. Recently the ranch has also been visited by tourists interested in learning about the farms various conservation programs. University classes from as far away as Caracas also visit, spending several days on the property which has become one of the unofficial field stations of the region. A number of Venezuelan initiated research projects have focused on the behavior of these poorly understood crocodiles and have likewise centered around these captive animals. Now research on wild populations has been initiated, consisting mostly of field density surveys, but PROFAUNA biologists have now started tracking wild adults which have been fitted with transmitters.   The compounds which house the ponds for the breeding adults, the pens for head-starting the hatchlings and juveniles, and the sundry incubation and husbandry facilities take up about 2 hectars of the 3,500 hectar cattle ranch. The compound has twenty-four hour security. The ranch itself, in addition to supporting 2,500 head of cattle has became a de facto wild life sanctuary. All entrances are secured and ranch hands patrol the property and prevent hunting and poaching. Numerous land management techniques have greatly enhanced the properties value for wildlife. Inventories of the ranch show a diversity of mammals ranging from savanna dwelling capybaras and giant anteaters, and gallery forest inhabited by howler monkeys and prehenscle-tailed porcupines, to the adjacent river with freshwater dolphins and manatees. At least 200 species of birds, and a variety of reptiles and amphibians occur on Agropecaria Puerto Miranda. Among the herps we have tallied are 23 species of snakes, including boa constrictors, rainbow boas and anacondas, several species of sideneck turtles (including mata matas), and golden tagues and green iguanas are abundant. Spectacle caymans are found throughout the ranch and in some places their densities are so high that along dikes active nests can be seen every twenty to fifty feet. Two free ranging sub-adult crocodiles have lived on the ranch for the last four years after escaping from their pens during a major flood. It is hoped that they will eventually breed once they achieve adult size. Our species inventories are far from complete, but it is clear that diversity is high and the ranch's management techniques have benefited a number of key animals of the region. Arrau Research March 2000 (Podocnemis expansa) Orinaco River, Venezuela   The conservation programs run by Pedro and the ranch hands have a relatively low profile. A modest sign at the main gate says "Aqui Protegemos El Caman dl Orinoco" (Cayman is the regional name for the crocodiles; the caman are called "Baba") and sports a fading painting of an Orinoco crocodile and its riverine habitat. The location of the program could not be more appropriate-- the Apure River, one of the major Llanos tributaries of the Orinoco borders one side of the ranch. The town of San Fernando is also a fitting site. It is one of the former major hide industry towns and in the 1930s the industry represented the major source of local income. An elaborate fountain in one of the towns main traffic circles is supported by a number of large sculptured and colorfully painted crocodiles commemorating former times. Fountain (San Fernando, Venezuela)   The Venezuelan government has made important advances in increasing public environmental awareness, and among the developing nations is a leader in this effort. Major attention has been focused at the primary school level, insuring that as the current generation matures that sound conservation ethics will be in place throughout the country. However, the traditional characterization of crocodiles is hard to modify, and thus the role of on-site education at the private captive breeding sites is important. These animals and the facility have become centers of public education through the news media, and an opportunity for TV footage of otherwise elusive animals. Awareness of the Orinoco crocodile in Venezuelan folklore and heritage, and the species role in the Llanos ecosystem is just now starting to develop. In 1988 the government established a new national park with boundaries that include large sections of river ideal for crocodile restoration. Since the mid-1990s captive bred animals, many of them from Agropecuaria Puerto Miranda, have been released into the park.   Despite the grave conservation status of the Orinoco crocodile the prognosis for long-range survival in the wild is promising. Orinoco crocodiles are fully protected by the national laws of the two countries in which they occur. Colombia declared it the country's first endangered species and has initiated protection and recovery plans. Additionally, Orinoco crocodiles are currently listed by CITES as Appendix I; USA Endangered Species Act as Endangered; and by the IUNC Red Data Book as Endangered. The captive breeding programs are beginning to realize their full potential, and there are plans to upgrade and enlarge some of the pens housing the breeding stock. The local commitment of privately owned ranches within the core range of the species has a number of important conservation components which will benefit local management efforts. The financial commitment of key property owners and the staffs overseeing the care of the crocodiles is vital for local commitment to the recovery of this species. These ranches employ a significant percentage of the local population and contribute in major ways to the region's overall economy. It is clear that many residents of the Llanos, where the captive breeding programs are in place, no longer consider crocodiles as vermin. On-site informal education programs where everyone from school children to government politicians can see the crocodiles and learn about the program have more lasting influence on attitudes than "canned" programs generated elsewhere.   The Tortoise Reserve, Inc. is delighted to support this program. The overall program is doing what is intended and needed; it is cost effective and funds do not get side routed to overhead and bureaucracy. By having the conservation, management and education being done locally with shared responsibility in the private sector, it allows governmental agencies to better focus their responsibilities of legislation and enforcement. My optimism for the value of programs of this type is probably overstated, but the active conservation efforts of Agropeuaria Puerto Miranda and the other ranches in the Llanos would be good models for addressing other globally significant conservation issues which demand local attention. References: Anonymous. 1980. Orinoco crocodiles hatched at Crandon Park Zoo. A.A.Z.P.A. Newsletter 21(9):1-4. Blohm, T. 1982. Husbandry of Orinoco crocodiles (Crocodylus intermedius) in Venezuela. p 267-285. In Crocodiles. IUNC Publ. N.S. 1982. Gland. Switzerland. ISBN 2-8032-209-X, 409p. Franz, R., S. Reid and C. Puckett. 1985. The discovery of a population of Orinoco crocodile, Crocodylus intermedius, in Southern Venezuela. Biol. Conserv. 23 (1985): 137-147. Godshalk. R. E. 1982. Status and conservation of Crocodylus intermedius in Venezuela. p 34-53 In Crocodiles. IUNC Publ. N.S. Gland. Switzerland. ISBN 2-8032-209-X. 409p. Humboldt, A. von. 1814. in Humboldt, A. and A. Bonpland. Voyage aux regions equinoxiales du Nouveau Continent, fait en 1799-1804. Pt. 1. Relation historique. Schoell, Paris. Meden, F. 1971. Situation report on crocodilians from three South American countries. p. 54-71. In Crocodiles. IUCN Publ (New Series). Suppl. paper 32, 191p. Thorbjarnarson, J. B. and R. Franz. 1987. Crocodylus intermedius. Catalogue of American Amphibians and Reptiles: 406.1-406.2 David S. Lee