Wednesday, May 16, 2012

Orinoco Crocodiles Are One Of The Most Highly Endangered Of All Crocodilians

orinoco crocodile
Orinoco Crocodiles have a body length between 3 and 4 m (9.8 - 13 ft). They are pale green/yellow in colour and they have short, powerful legs and a long, powerful tail. Orinoco Crocodiles breed during the dry season and 14 weeks after mating the female will dig a nest in a sand bank and lay her eggs. After approximately 3 months the young crocodiles hatch and call out to their mother.
She will dig out the youngsters, carry them to the water and she will defend them until they are a year old. "For handbags, belts, and shoes, Orinoco crocodiles in South America were hunted ruthlessly for decades. By the mid-1960s they had been nearly wiped out in the Orinoco River Basin of Venezuela and Colombia. In 1976 hunting was banned, but the damage was done: A census found fewer than 300 animals. Conservationists and scientists have worked hard to bring back this beleaguered reptile, which can exceed 20 feet [6 meters] in length. Four captive breeding centers in Venezuela have reared and released more than 1,300 crocodiles into the Orinoco and its tributaries since 1990."
  
The Orinoco crocodile is one of the larger crocodilians (a group that also includes alligators, caimans and the gharial), with a relatively narrow snout and a minor swelling in front of the eyes. It is South America's largest predator, by mass, and males have been reported up to 7 metres in length, although the maximum size recorded in recent studies has not exceeded 5 metres. Three different colour variations exist with the most common being 'Amarillo': a light tan body and scattered dark areas. In captivity, it has been noted that the skin can change colour over long periods of time; this phenomenon has been recorded in other species that can gradually change the amount of melanin in their skin (2)(4).
  
Range
  
Severely fragmented populations are found in the lower reaches of the Orinoco River in Venezuela and Colombia.
  
Habitat
  
Once associated with a wide variety of habitats (from tropical forests to the streams of the Andes foothills), this species has now been restricted to the Llanos savannah and associated seasonal freshwater rivers.
  
Biology
  
When the waters subside in the dry season, Orinoco crocodiles retreat into burrows excavated into riverbanks. Breeding females excavate hole-nests on exposed sand banks, typically laying around 40 eggs. The female remains close to the nest site to guard it from vultures and tegu lizards. Hatching occurs 2.5 to 3 months later, which coincides with the rains that bring a rise in water levels, and females have been reported to protect pods of juveniles for up to 3 years.
  
Adults are opportunistic, feeding on a wide variety of prey that are either in or near the water such as fish, large birds and small mammals. Data on lifespan are extremely sparse but, like other large crocodilians, Orinoco crocodiles may live as long as 70 to 80 years.
  
Threats
  
The Orinoco crocodile was hunted to the brink of extinction for its skin during the 1930s to 60s and the population has shown little signs of recovery since, although reintroduction programs are underway. Crocodiles could be found in large numbers around small water areas during the dry season, which made them easy targets for hunters. Today there are an estimated 250 to 1,500 individuals left in the wild. Illegal hunting for meat and for teeth (which are thought to have medicinal properties), along with the collection of eggs and juveniles remains the major threat to this species. Further threats are posed from continued habitat destruction, killing by local people, and from competition with the spectacle caiman (Caiman crocodilus), which is found in the same area.
  
Conservation
  
Orinoco crocodiles are one of the most highly endangered of all crocodilians due to the small size and highly fragmented nature of their population. International trade in this species is banned under Appendix I of the Convention of International Trade in Endangered Species (CTIES), and it is protected throughout much of its range. These protection measures however, are largely ineffective and unforced and illegal poaching remains the principal threat to this species. In Colombia very little is known about the current status of the species and this remains a high priority for any conservation action plan. In Venezuela a reintroduction/ restocking plan has been developed and captive breeding is carried out at a number of sites. Effective monitoring of released crocodiles is required and protection measures need to be properly enforced, in order to help this species recover from such crippling over-exploitation in the past.

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