Morelet's Crocodile
Crocodylus moreletii
Common name: Mexican crocodile, Soft belly, Belize crocodile, Central American crocodile, Crocodile de Morelet (French), Cocodrilo de Morelet, Cocodrilo de Pantano y Lagarto (Spanish)
Taxonomy:
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodylia
Family: Crocodylidae
Subfamily: Crocodylinae
Genus: Crocodylus
Species: Crocodylus moreletti
Identification:
The Morelet’s Crocodile is a small crocodile, seldom exceeding 10 feet in length. The rest of the dorsal scales are flat in contrast to American crocodile. One distinguishing characteristic of Morelet’s Crocodile is that the vertical rows of scales on the sides of the tail are separated in places by isolated scales or rows of smaller scales, which don’t contact the dorsal rows of large scales on the top of the tail. Also, its length and width of the head is usually shorter and broader than American crocodile. Its suture joining the maxilla and premaxilla bones of the upper jaw is straight and transverse in contrast to American Crocodile’s V- or W-shaped. Its common color is yellowish black; males are usually darker than females, which remain more yellowish, (Navarro, 2002).
Life History:
In 1850, the Morelet’s Crocodile was discovered in Mexico by the French naturalist named P.M.A. Morelet. It wasn’t realized that they were a separate species until the 1920s. In the 1940s and 1950s, they were rapidly endangered and threatened to extinction. With improving farm systems and the laws protecting endangered species, knowledge of this species are very new and recently discovered.
Diet:
Morelet’s crocodile are predatory carnivores and often eat small aquatic vertebrates and invertebrates; flying insects, small mammals, birds, reptiles, fish, crabs and domestic animals including dogs and goats. Hatchlings, or baby Morelet’s Crocodiles, usually eat slugs and snails.
Habitat:
Atlantic regions of Central America from Tamaulipas, Mexico south to northern and central coastal Belize and northern Guatemala; lakes, rivers, waterholes, wells, and coastal lagoons with floating plant life. Sometimes they are found on the savanna with freshwater canals and small elevated areas of rainforest. During the rainy season in areas of savanna, the Morelet’s Crocodiles spreads over the large flooded areas. When it stops raining, they will get together.
Reproduction:
The nesting season of Morelet’s Crocodile usually happen in from April to June before the beginning of the rainy season and vary from one region to another. The female can lay about 20-40 eggs in a nest made of gathered plants. Then, the eggs will hatch after 75-80 days. They usually breed eggs and hatchlings at sea level or very low coastal elevations, (Navarro, 2002). Female opens the nest with her feet and mouth, uncovers the egg chamber, and transports the hatchlings in her jaws to the waters’ edge. She’s very protective of the nest and the hatchlings.
Behavior:
Belize crocodiles always move slowly over land but they can cover ground quickly in short bursts. They may use vocal signals extensively in their behavior, in communicating with one another, but their sounds have been little-studied. Juveniles, or hatchlings, are known to give alarm calls when threatened. When it occurs, the parents respond by coming to their rescue quickly. They adore basking in the sunshine along the banks of rivers, streams, and ponds. They may resemble themselves as above floating logs, which allows them to move close to shore and capture animals that come to the water to drink. Even though they are possibly dangerous to people, their sizes are much smaller to make a successful attack.
Recent research:
In August 2003, Morelet’s Crocodile eggs were discovered for having organochlorine (OC) pesticides, which is considered to be endocrine-disrupting contaminants (EDCs), inside in 3 different localities in northern Belize. During that time, population were declining and reproductive abnormalities in the species were exposed to same chemicals. It triggered the research to determine OC concentrations in soil, sediment, and nesting material from contaminated and reference sites. Also they monitored the response of crocodile populations to OC exposure, and biomarker response of crocodiles to OC exposure individually. The results came out that both sites were having similar concentrations, but it’s believed that one uncontaminated reference site didn’t represent appropriately. Unfortunately, the research came out in a unsuccessful finding and the researchers focused again on the two sites: New River Watershed and the Gold Button Lagoon. They discovered that males and juveniles don’t have any exposure to OCs but then later found to have OC pesticides in their caudal scutes (scales on the tails), which proved that they already have been exposed to OCs way before.
Economic/ecological service:
*Before 1981, the Morelet’s Crocodile was hunted heavily in Belize for its hide. Its fine belly skin makes a high quality leather, this species has been severely exploited. (Dickson et al, 2000). Under the Wildlife Protection Act, the population has since rebounded. Today it is still considered as threatened with extinction, (Belize Zoo, 2012). However, it provide economic incentives to encourage local communities to participate in protecting the crocodiles and their habitats. Establishing a system of farming to collect 50-75% percent of eggs or hatchlings from the wild, raising them to commercial size, and return a proposed percentage to the wild will improve the survival rate, (National Research Council, 1983).
*Hatchling crocodiles are prey to birds, such as roadside hawk, laughing falcon, wood ibis, jabiru, and great blue heron.
Literature Cited:
Please note that the following references may have either been removed or relocated by the webpage owners since the time this student report was created.
National Research Council. Crocodiles as a Resource for the Tropics. Washington, DC: National Academy Press, 1983. Print.
Neill, Wilfred T. The Last of the Ruling Reptiles: Alligators, Crocodiles, and Their Kin. USA: Columbia University Press, 1971. Print.
Grenard, Steve. Handbook of Alligators and Crocodiles. Malabar, Florida: Krieger Publishing Company, 1991. Print.
Huchzermeyer, F.W. Crocodiles: Biology, Husbandry and Diseases. Cambridge, MA: CABI Publishing, 2003. Print.
Dickson, Barnabas and Hutton, Jon. Endangered Species, Threatened Convention. USA: Earthscan, 2000. Print.
External links:
Please note that the following links may have either been removed or relocated by the webpage owners since the time this student report was created.
Anonymous. Belize Zoo: Morelet’s Crocodile. http://www.belizezoo.org/reptiles/crocodile.html, May 29, 2012
Navarro, Carlos J. The Return of Morelet’s Crocodile. 2002. http://www.reptilia.net/articulos_ing/036.pdf May 30, 2012.
Anderson, Todd A. and McMurry, Scott T. Exposure and Response of Morelet’s Crocodile Populations to Endocrine Disrupting Compounds in Belize, Central America, 2003. http://epa.gov/ncer/science/endocrine/pdf/wildlife/r826310_mcmurry-030105-final.pdf May 31, 2012