Orinoco crocodile - Crocodylus intermedius

[Ceratodromeus]

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Saruropsida
Order: Crocodylia
Family: Crocodylidae
Subfamily: Crocodylinae
Genus: Crocodylus
Species: C.intermedius

Geographic distribution & habitat use
This species is restricted to the Orinoco River basin in Colombia and Venezuela. They have been occasionally reported on the island of Trinidad, but this has not been confirmed and witnesses may have mistaken an American crocodile for the rarer species. This crocodile was once thought to have inhabited a wide range of riparian habitats, from tropical forests to the streams of the Andes foothills. Today, this species is restricted to the Llanos savannah and associated seasonal freshwater rivers.


Biology
The Orinoco crocodile (Crocodylus intermedius) is a critically endangered crocodile. Its population is very small and it can only be found in freshwater environments in Colombia and Venezuela, in particular the Orinoco River and its tributaries. Extensively hunted for their skins in the 19th and 20th centuries, this species is one of the most critically endangered species of crocodiles. It is a very large species, in fact the largest species of crocodilian and predator in the Americas. Males have been reported up to 6.6 m (22 ft) in the past, but such sizes do not exist today, 5.2 m (17 ft) being a more widely accepted maximum size. Males average at 4.1 m (13 ft) in length weighing 380 kg (840 lb), while females are slightly smaller averaging 225 kg (496 lb). Sexual dimorphism is not as profound as in some other species. The coloration is light even in adults.



The Orinoco crocodile can be recognised by its relatively long snout, which is narrower than that of the somewhat similar-looking American crocodile. This species generally has a pale tan hide, though at least three coloration variations are known, with some almost completely yellowish and some a dark brownish-gray. 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. These crocodiles have dark-brown markings, which present as more pronounced bands in younger specimens and as scattered markings on mature ones.

It stalks both aquatic and terrestrial prey. As a large adult, terrestrial prey may include capybara, domestic animals, and even occasionally other large predators if the opportunity arises.Similar to many of the larger crocodile species, the Orinoco crocodile has also been observed catching and eating smaller species of crocodilians, such as caimans and sometimes cannibalizing smaller individuals of its own kind. Attacks on humans have been reported, but this is highly unlikely to be a common behavior, given the extremely small population of the species and its relative isolation from large human settlements. Its large size may pose a threat, but this species has a less aggressive temperament compared to other large crocodiles, which reduces the likelihood of it preying on humans.

When water recedes in the dry season, Orinoco crocodiles retreat to burrows they excavate into the riverbanks. The adult pair mates during the drier period of the year, and usually 14 weeks after mating, the female crocodile will dig a nest and lay about 40 eggs. It is a hole-nester and usually makes the nest on a sand bank. The eggs incubate for around three months. During the night, they hatch and call to their mother which digs them out of the nest and carries them to the water, which is considerably higher at this point. Young Orinoco crocodiles are often at risk from predation by American black vultures, tegu lizards, anacondas, caimans, coatis, jaguars, and other carnivores, though these species are sometimes caught and killed by the defending mother crocodile. Females have defended pods of juveniles for over three years, though closer to one year to independence is generally most common. A study of captive Orinoco crocodiles noted the aggressive behavior of adults while nesting and noted that the normally relatively docile crocodilians could not be approached while they were actively brooding.

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en.wikipedia.org/wiki/Orinoco_crocodile

[Ceratodromeus]

Interview with Venezuelan crocodile on the conservation status of Orinoco crocodiles:

"Andrés Eloy Seijas is the most prominent crocodile expert in Venezuela. He has spent many years studying the Orinoco crocodile (Crocodylus intermedius) and other species.

César L. Barrio-Amorós: How many years have you worked with the Orinoco crocodile?

Andrés Eloy Seijas: I have been involved in direct work with this species since I began working at the UNELLEZ (Universidad Experimental de los Llanos, Ezequiel Zamora) in 1989.

CBA: What is the current population status of the Orinoco croc?

AES: The Capanaparo river population, studied by Alfonso Llobet from 2000 to 2001, numbered about 500 individuals. This was basically the same number that was there when John Thorbjarnarson conducted his census 10 years earlier. In 1999, I estimated a population of 550 in the Río Cojedes, although there are now signals of decline. Currently, I would estimate about 350 adults. Another known population is that in the Río Manapire, (Guárico state), with scarce individuals over a huge extension. The population must be around 50 to 100 specimens older than 1 year of age. The last serious study made was by Rafael Antelo from 2000 to 2006 in Hato El Frío, with around 500 individuals. There are also individuals expanded throughout the vast Orinoco River, but not forming stable populations (for example at the Ventuari river, Amazonas state). All numbers considered, I would estimate a total current population that is close to 1,500 specimens.

CBA: In all your years studying the Orinoco crocodile, have you seen any signal of recovery?

AES: The only evidence of an increasing population is that of the Hato el Frío. The other localities exhibit either stable or declining numbers. Seven thousand young crocodiles [that were bred in captivity] have been released; supposing a pessimistic survival rate of 15 percent, there could be 950 "new" crocs.

CBA: Do you think that the Orinoco crocodile has a future in Venezuela?

AES: Things are not OK. All the time we know about crocs killed in the Capanaparo, Cojedes or Manapire. There are no safe places for the species. It is facing real danger, though it is too soon to speak about extinction.

CBA: Can you explain John Thorbjarnarson’s contribution to Orinoco crocodile conservation?

AES: When John came to Venezuela, Cecilia and Thomas Blohm were already working on a conservation program for the species. John provided major support, and he began to more effectively breed and raise Orinoco crocs. He also made a great scale assessment of the country, and studied the Capanaparo population in detail. His constant support and evaluation of the program at Hato Masaguaral provided important details of the breeding behavior of Crocodylus intermedius.

John (or Juan Caiman, as the locals called him) was an important influence for everyone in Venezuela who works with crocodiles, and not only with the Orinocroc. He won the confidence, respect and affection of the local people as well as the personnel of the Environment Ministry. He tutored many local biologists, and I personally have much for which to thank him, as once he started to work with the Wildlife Conservation Society, he supported all my investigations. Most of the equipment we got was thanks to his efforts. Most of the methodology we apply in field studies are inspired by him. John was a very special person. You never will find anybody with even a minimum of reproach for him.

CBA: Tell us about Brady Barr’s capture of the huge male croc.

AES: Brady Barr wanted to catch a huge Orinoco crocodile. I explained to him the difficulties involved in capturing one in the Río Cojedes, because the shores are so steep and muddy. Plus, the boat we had was too small. After hours of navigation, and to my relief, we did not find any crocs. However, when we were leaving, Brady located a big male out of the water near a pond. After a briefing, he went in alone and was able to secure its snout. Then the rest of the team went quickly to help, and with six people we at last were able to secure the monster, which measured more than 14 feet.

CBA: The conservation of those species considered dangerous to people is a difficult topic. Do you think that people agree with the need to conserve this species?

AES: Not all people see a need to preserve this formidable animal. The case of Francisco Conde does not help to create a favorable image (read about Conde in the article,"Orinoco Croc Encounters" in the February 2011 issue of REPTILES). The Orinoco crocodile is not the man-eating monster that some people have in mind. People must learn to live with it, reducing the opportunities for unfortunate occurrences." "
www.reptilesmagazine.com/Reptile-Magazines/Reptiles-Magazine/February-2012/Orinoco-Crocs-Sidebar/