I surveyed the river from the town of Maripa where the Caura meets the Orinoco to the Para Falls. A distance of about 150 km. The survey was conducted at the end of the dry season when the Caura is at its lowest level. Observations were made using binoculars from a motorized boat. Turtles were approached slowly for better identification and, when possible, were captured. Sandy beaches along the river were visited to assess the presence of turtle nests. Every Indian village was visited and information associated with turtles was collected. When possible I met with the local Indian chiefs. Finally, two daytime surveys were conducted within the forest near Boca de Ninchare in search of tortoises.
Species Observed and Occurrence
I observed two species of freshwater turtles (Podocnemis unifilis and Chelus fimbriatus) and one species of tortoise (Geochelone denticulata). According to the Yekuana Indians, three more species of freshwater turtles (Podocnemis expansa, Platemys platycephala, and Rhinoclemmys punctularia) and one tortoise (Geochelone carbonaria) are also known to occur in and along the Caura. Podocnemis expansa is found downstream where habitat appears similar to that of the Orinoco P. expansa populations (Pritchard and Trebbau 1984). Platemys platycephala is found in the vicinity of Boca de Ninchare, but are believed to be inactive during the dry season explaining the absence of observations (Métrailler and Le Gratiet 1996, Yekuana Indians 2001). The Yekuana Indians say that Rhinoclemmys punctularia can be found upstream of Para Falls where the Caura river is smaller.
Along the Caura, the Yekuana Indians call C. fimbriatus “matamata”. Geochelone carbonaria and G. denticulata are called “wayamu”. Platemys platycephala is named “Kudamashua”. Finally, Podocnemis unifilis is called “tadequeya” in the Yekuana language.
Importance of Chelonian in the Indian Communities
Podocnemis unifilis represents an important part of the indigenous diet among fish and wild mammals. The Yekuana Indians fish P. unifilis adults year-round. Turtles can be captured by hand in the dry season in the Ninchare river due to the low water level (max. depth: 2 m). Adults are usually captured accidentally in fishing nets or intentionally using a fishhook. Fruits such as papaya, platanos and bananas are the usual baits. The turtle eggs are not eaten as often as the adults. Geochelone carbonaria and G. denticulata are usually accidentally captured in the forest a few kilometers from the village while hunting for other animals. The meat of P. unifilis is preferred to that of both Geochelone. During my visit in most of the Yekuana Indian settlements, I observed 1-2 G. denticulata kept alive for a few days. They are cruelly immobilized by passing sticks across the front and rear openings of the shell and tying the sticks to the sides. Some families will sell tortoises when going to Maripa, the nearest town, while others will just keep them for their own diet. No G. carbonaria were observed, but according to the Yekuana Indians this species lives in sympatry with G. denticulata. During the dry season, tortoises are usually found near water bodies.
The status of G. denticulata is classified as “insufficiently known” by the IUCN Red Data Book (IUCN, 1982) and indeterminate in Colombia by Castano Mora (1997). The status is unknown along the Caura, but the species appears common according the Yekuana Indians. The status of G. carbonaria is unknown in Latin America (IUCN, 1982) and endangered in Colombia (Castano-Mora 1997). Along the Cuara the status is unknown. The Yekuana Indians observe fewer G. carbonaria than G. denticulata.
For the past three years the Yekuana Indian from Boca de Ninchare have implemented a conservation program for Podocnemis unifilis nests along the de Ninchare river. This river is a major tributary to the Caura (30 m wide; max. 10 m deep in winter; max. 5 m deep in summer). A project station is located about 60 km upstream from Boca de Ninchare where three Indians work on-site during the nesting season. Twelve major nesting sites have been protected from predators and poachers with 6,000 hatchlings released in 2000. During the first year, 270 turtles were captured and marked, 370 the second year (3 recaptured), and 670 the last year (7 recaptured). Turtles are captured using fishing nests and SCUBA diving during the dry season. Very few matamata were captured during the P. unifilis mark-recapture program. Only one the second year and one the third year. The low capture of C. fimbriatus could be attributed to capture methods that are totally inefficient for that species. Additionally, the Ninchare river may not offer a good habitat for the matamata. Even though the matamata is a more cryptic turtle than P. unifilis, it appears to be found in lower density along the Caura and tributaries. However their populations are not threatened due to the absence of human consumption or even habitat alteration.
In Latin America, P. unifilis is highly exploited. It is classified as vulnerable in the IUCN Red Data Book (IUCN, 1982) and at least vulnerable in Colombia by Castano Mora (1997). The Orinoco populations of Colombia are considered threatened and those in Venezuela are unknown, but probably highly reduced. Based on fishing capture and personal observations, populations of P. unifilis in the Rio Caura are also becoming vulnerable (pers. com. Rodriguez 2001). Along Rio Caura, the number of poachers and fishermen has increased over the past few years reducing the number of P. unifilis. Through sustainable management of their natural resources, the Yekuana Indians intend to conserve the Rio Ninchare and its turtles. One part of Rio Ninchare has been declared a national monument by the Venezuelan government and the involvement of the Indians living in the vicinity must be encouraged by supporting their conservation-management plan. However, the turtle hatchling program should be implemented only if the techniques they employ are evaluated and information on the biology of the species collected.
If you want to have more information on the Podocnemis unifilis program or support the Yekuana Indian community with this project, please contact in Spanish: Alberto Rodriguez, Organizacion Indegena de la Cuenca de Caura Tiuyujani, Apartado Postal 590 C.P. 8001, Ciudad Bolivar, Estado Bolivar, Venezuela.
Castano-Mora, O V. 1997. Status of the tortoises and freshwater turtles of Colombia. Proceedings: Conservation, Restoration and Management of Tortoises and Turtles-An international conference, 302-306.
IUCN/SSC. 1982. The IUCN Amphibia-Reptilia Red Data Book. Part I. Testudines, Crocodylia, Rhynocephalia (B.Goombridge, comp.). IUCN, Gland, Suitzerland. 426 pp.
Métrailler S., G. Le Gratier. 1996. Tortues continentales de Guyane Francaise. Suitzerland. 127pp.
Rodriguez A. April 2001. Personal communication.
Pritchard, P.C.H. and P. Trebbau. 1984. The Turtles of Venezuela. Soc. Stud. Amph. Rept., Contrib. Herptol. 403pp.