Morelet's crocodiles are found on the eastern coastal plain of Mexico, across most of the Yucatan peninsula, and throughout Belize and northern Guatemala. Their range also overlaps that of the American crocodile, but the relationships between the two are unknown. Some Morelet's crocodiles have escaped from captive breeding areas in Mexico outside their normal range.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
- Britton, A. 2002. "Crocodilian Species-Morelet's Crocodile (Crocodylis Moreletii)" (On-line ). Crocodilian Species List. Accessed 03/18/03 at http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csl.html.
Distribution: Belize, Guatamala, Mexico (Chiapas)
Type locality: "Lac Flores (Yucatan)," Guatemala; restricted by Smith and Taylor (1950: 211), and Smith and Taylor (1950: 318) to "Guatemala, El Peten, Laguna de Peten".
The primary distinguishing feature of Crocodylus moreletii is the snout, which is uncharacteristically blunt for a crocodile. The snout has nostrils centered at its end. The eyes are situated behind the snout and ears behind the eyes. The location of all the sensory receptors are on the same plane (the top of the head) which allows them to be completely submerged in water and still have the ability to hear, see, and smell. Their eyes, which are silvery-brown, have special eyelids with nictitating membranes covering them, allowing for vision underwater. Morelet's crocodiles generally have 66 to 68 teeth, with the distinguishing purely Crocodylus characteristic of having them in perfect alignment. Their appearance and color is similar to the American crocodile, but Morelet's crocodiles tend to be a darker grayish-brown. Adults have dark bands and spots before the tail, while juveniles are a brighter yellow with black banding. Morelet's crocodiles lack bony plates (ventral osteoderums) beneath the skin. They have powerful legs with clawed webbed feet, and large tails that allow them to swim with powerful thrusts. They are medium-sized crocodiles, averaging 3 m and attaining a maximum of 4.7 m.
Range mass: 38.5 to 58.1 kg.
Average mass: 51 kg.
Range length: 2.2 to 4.7 m.
Average length: 3.0 m.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger
- Belize Zoo. 2003. "Morelet's Crocodile Video" (On-line video). Accessed March 18, 2003 at http://www.belizezoo.org/zoo/zoo/herps/cro/cro1.html.
Marismas Nacionales-San Blas Mangroves Habitat
This taxon is found in the Marismas Nacionales-San Blas mangroves ecoregion contains the most extensive block of mangrove ecosystem along the Pacific coastal zone of Mexico, comprising around 2000 square kilometres. Mangroves in Nayarit are among the most productive systems of northwest Mexico. These mangroves and their associated wetlands also serve as one of the most important winter habitat for birds in the Pacific coastal zone, by serving about eighty percent of the Pacific migratory shore bird populations.
Although the mangroves grow on flat terrain, the seven rivers that feed the mangroves descend from mountains, which belong to the physiographic province of the Sierra Madre Occidental. The climate varies from temperate-dry to sub-humid in the summer, when the region receives most of its rainfall (more than 1000 millimetres /year).
Red Mangrove (Rhizophora mangle), Black Mangrove (Avicennia germinans), Buttonwood (Conocarpus erectus) and White Mangrove trees (Laguncularia racemosa) occur in this ecoregion. In the northern part of the ecoregion near Teacapán the Black Mangrove tree is dominant; however, in the southern part nearer Agua Brava, White Mangrove dominates. Herbaceous vegetation is rare, but other species that can be found in association with mangrove trees are: Ciruelillo (Phyllanthus elsiae), Guiana-chestnut (Pachira aquatica), and Pond Apple (Annona glabra).
There are are a number of reptiles present, which including a important population of Morelet's Crocodile (Crocodylus moreletii) and American Crocodile (Crocodylus acutus) in the freshwater marshes associated with tropical Cohune Palm (Attalea cohune) forest. Also present in this ecoregion are reptiles such as the Green Iguana (Iguana iguana), Mexican Beaded Lizard (Heloderma horridum) and Yellow Bellied Slider (Trachemys scripta). Four species of endangered sea turtle use the coast of Nayarit for nesting sites including Leatherback Turtle (Dermochelys coriacea), Olive Ridley Turtle (Lepidochelys olivacea), Hawksbill Turtle (Eretmochelys imbricata) and Green Turtle (Chelonia mydas).
A number of mammals are found in the ecoregion, including the Puma (Puma concolor), Ocelot (Leopardus pardalis), Jaguar (Panthera onca), Southern Pygmy Mouse (Baiomys musculus), Saussure's Shrew (Sorex saussurei). In addition many bat taxa are found in the ecoregion, including fruit eating species such as the Pygmy Fruit-eating Bat (Artibeus phaeotis); Aztec Fruit-eating Bat (Artibeus aztecus) and Toltec Fruit-eating Bat (Artibeus toltecus); there are also bat representatives from the genus myotis, such as the Long-legged Myotis (Myotis volans) and the Cinnamon Myotis (M. fortidens).
There are more than 252 species of birds, 40 percent of which are migratory, including 12 migratory ducks and approximately 36 endemic birds, including the Bumblebee Hummingbird, (Atthis heloisa) and the Mexican Woodnymph (Thalurania ridgwayi). Bojórquez considers the mangroves of Nayarit and Sinaloa among the areas of highest concentration of migratory birds. This ecoregion also serves as wintering habitat and as refuge from surrounding habitats during harsh climatic conditions for many species, especially birds; this sheltering effect further elevates the conservation value of this habitat.
Some of the many representative avifauna are Black-bellied Whistling Duck (Dendrocygna autumnalis), Great Blue Heron (Ardea herodias), Roseate Spoonbill (Ajaia ajaja), Snowy Egret (Egretta thula), sanderling (Calidris alba), American Kestrel (Falco sparverius), Blue-winged Teal (Anas discors), Mexican Jacana (Jacana spinosa), Elegant Trogan (Trogan elegans), Summer Tanager (Piranga rubra), White-tailed Hawk (Buteo albicaudatus), Merlin (Falco columbarius), Plain-capped Starthroat (Heliomaster constantii), Painted Bunting (Passerina ciris) and Wood Stork (Mycteria americana).
- L.A. Bojórquez-Tapia, S. Díaz-Mondragón, and R Saunier, R. 1997. Ordenamiento Ecológico de la Costa Norte de Nayarit. OEA-IEUNAM, México.
- World Wildlife Fund & C. Michael Hogan. 2013."Marismas Nacionales-San Blas mangroves". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed. Mark McGinley
Belizean Pine Forests Habitat
This species is found in the Belizean pine forests along the Central America's northwestern Caribbean Sea coast; the ecoregion exhibits relatively well preserved fragments of vegetation as well as a considerable abundance of fauna. This ecoregion comprises a geographically small portion of the total land area of the ecoregions of Belize. There is relatively low endemism in the Belizean pine forests, and only a moderate species richness here; for example, only 447 vertebrate taxa have been recorded in the ecoregion. The ecoregion represents one of the few examples of lowland and premontane pine forests in the Neotropics, where the dominant tree species is Honduran Pine (Pinus caribaea var. hondurensis), which requires periodic low intensity burns for its regeneration. The vegetation is adapted to the xeric, acidic and nutrient-poor conditions that occur primarily in the dry season.
In the forest of the Maya Mountains, vegetation reaches higher altitudes, the topography is more rugged and crossed by various rivers, and nighttime temperatures are lower. The pine trees are larger and numerous, and the pine forest intersects other formations of interest such as rainforest, Cohune Palm (corozal), cactus associations, and others. About eleven percent of Belize is covered by natural pine vegetation. Only two percent represents totally closed forests; three percent semi-closed forests; and the remaining six percent pine savannas, that occupy coastal areas and contain isolated pine trees or stands of pine trees separated by extensive pastures. In addition to human activity, edaphic factors are a determining matter in this distribution, since the forests on the northern plain and southern coastal zone are on sandy soils or sandy-clay soils and usually have less drainage than the more fertile soils in the center of the country.
At elevations of 650 to 700 metres, the forests transition to premontane in terms of vegetation. At these higher levels, representative tree species are Egg-cone Pine (Pinus oocarpa), which crosses with Honduras Pine (P. hondurensis), where distributions overlap, although belonging to subsections of different genera; British Honduras Yellowwood (Podocarpus guatemalensis) and Quercus spp.; moreover, and in even more moist areas there is a predominance of Jelecote Pine (Pinus patula), together with the palm Euterpe precatoria var. longivaginata and the arboreal ferns Cyathea myosuroides and Hemitelia multiflora.
A number of reptilian species are found in the Belizean pine forests, including: Guatemala Neckband Snake (Scaphiodontophis annulatus); Indigo Snake (Drymarchon corais); On the coasts, interior lakes and rivers of Belize and by extension in this ecoregion there are two species of threatened crocodiles: American Crocodile (Crocodylus acutus) and Morelet's Crocodile (C. moreletii), while observation of the Central American River Turtle (Dermatemys mawii CR) is not uncommon in this ecoregion.
Also to be noted is the use of this habitat by the Mexican Black Howler (Alouatta pigra), which can be considered the most endangered howler monkey of the genus, and the Central American spider monkey (Atteles geoffroyi). Both species experienced a decline due to the epidemic yellow fever that swept the country in the 1950s. The five feline species that exist in Belize: Jaguar (Panthera onca), Puma (F. concolor), Ocelot (Leopardus pardalis), Margay (Leopardus wiedii) and Jaguarundí (Herpailurus yagouaroundi) are in appendix I of CITES, as well as the Central American tapir (Tapirus bairdii) can been seen with relative frequency. Belize has the highest density of felines in Central America. The tapir is abundant around rivers. The White-lipped Peccary (Tayassu pecari) is also present in the ecoregion.
Although most of the amphibians and reptiles are found in humid premontane and lowland forests, the only endemic frog in this ecoregion, Maya Mountains Frog (Lithobates juliani), is restricted to the Mountain Pine Ridge in the Maya Mountains. Salamanders in the ecoregion are represented by the Alta Verapaz Salamander (Bolitoglossa dofleini NT), whose males are arboreal, while females live under logs. Anuran taxa found in the ecoregion include: Rio Grande Frog (Lithobates berlandieri); Sabinal Frog (Leptodactylus melanonotus); Northern Sheep Frog (Hypopachus variolosus); Stauffer's Long-nosed Treefrog (Scinax staufferi); and Tungara Treefrog (Engystomops pustulosus).
Present in the ecoregion are a number of avian species, including the endangered Yellow-headed Amazon Parrot (Amazona oratrix EN), although this bird is adversely affected by ongoing habitat destruction. Of particular interest is the presence in this ecoregion of Central America's highest procreative colony of Jabiru (Jabiru mycteria), a large migratory bird, particularly in the Crooked Tree sanctuary, on the country's northern plains.
- C. Michael Hogan & World Wildlife Fund. 2013."Belizean pine forests". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
- E. Dinerstein, D.M. Olson, et al. 1995. A Conservation Assessment of the Terrestrial Ecoregions of Latin America and the Caribbean. The World Bank in association with WWF, Washington, D.C. ISBN: 0821332961
Mesoamerican Gulf-Caribbean Mangroves Habitat
This taxon is found in the Mesoamerican Gulf-Caribbean mangroves ecoregion, but not necessarily exclusive to this region.The Mesoamerican Gulf-Caribbean mangroves occupy a long expanse of disjunctive coastal zone along the Caribbean Sea and Gulf of Mexico for portions of Central America and Mexico. The ecoregion has a very high biodiversity and species richness of mammals, amphibians and reptiles. As with most mangrove systmems, the Mesoamerican Gulf-Caribbean ecoregion plays an important role in shoreline erosion prevention from Atlantic hurricanes and storms; in addition these mangroves are significant in their function as a nursery for coastal fishes, turtles and other marine organisms.
This disjunctive Neotropical ecoregion is comprised of elements lying along the Gulf of Mexico coastline of Mexico south of the Tampico area, and along the Caribbean Sea exposures of Belize, Honduras, Guatemala, Nicaragua, Costa Rica and Panama.There are 507 distinct vertebrate species that have been recorded in the Mesoamerican Gulf-Caribbean mangroves ecoregion.
Chief mangrove tree species found in the central portion of the ecoregion (e.g. Belize) are White Mangrove (Laguncularia racemosa), Red Mangrove (Rhizophora mangle), and Black Mangrove (Avicennia germinans); Buttonwood (Conocarpus erectus) is a related tree associate. Red mangrove tends to occupy the more seaward niches, while Black mangrove tends to dominate the more upland niches. Other plant associates occurring in this central part of the ecoregion are Swamp Caway (Pterocarpus officinalis), Provision Tree (Pachira auatica) and Marsh Fern (Acrostichum aureum).
The Mesoamerican Gulf-Caribbean mangroves ecoregion has a number of mammalian species, including: Mexican Agouti (Dasyprocta mexicana, CR); Mexican Black Howler Monkey (Alouatta pigra, EN); Baird's Tapir (Tapirus bairdii, EN); Central American Spider Monkey (Ateles geoffroyi, EN); Giant Anteater (Myrmecophaga tridactyla); Deppe's Squirrel (Sciurus deppei), who ranges from Tamaulipas, Mexico to the Atlantic versant of Costa Rica; Jaguar (Panthera onca, NT), which requires a large home range and hence would typically move between the mangroves and more upland moist forests; Margay (Leopardus wiedii, NT); Mantled Howler Monkey (Alouatta palliata); Mexican Big-eared Bat (Plecotus mexicanus, NT), a species found in the mangroves, but who mostly roosts in higher elevation caves; Central American Cacomistle (Bassariscus sumichrasti).
A number of reptiles have been recorded within the ecoregion including the Green Turtle (Chelonia mydas, EN); Hawksbill Sea Turtle (Eretmochelys imbricata, CR); Central American River Turtle (Dermatemys mawii, CR), distributed along the Atlantic drainages of southern Mexico to Guatemala; Morelets Crocodile (Crocodylus moreletii, LR/CD), a crocodile found along the mangroves of Yucatan, Belize and the Atlantic versant of Guatemala.
Some of the other reptiles found in this ecoregion are the Adorned Graceful Brown Snake (Rhadinaea decorata); Allen's Coral Snake (Micrurus alleni); Eyelash Palm Pitviper (Bothriechis schlegelii); False Fer-de-lance (Xenodon rabdocephalus); Blood Snake (Stenorrhina freminvillei); Bridled Anole (Anolis frenatus); Chocolate Anole (Anolis chocorum), found in Panamanian and Colombian lowland and mangrove subcoastal forests; Furrowed Wood Turtle (Rhinoclemmys areolata. NT); Brown Wood Turtle (LR/NT); Belize Leaf-toed Gecko (Phyllodactylus insularis), which occurs only in this ecoregion along with the Peten-Veracruz moist forests.
Salamanders found in this ecoregion are: Cukra Climbing Salamander (Bolitoglossa striatula); Rufescent Salamander (Bolitoglossa rufescens); Alta Verapaz Salamander (Bolitoglossa dofleini, NT), the largest tropical lungless salamander, whose coastal range spans Honduras, Guatemala and the Cayo District of Belize; Colombian Worm Salamander (Oedipina parvipes), which occurs from central Panama to Colombia; La Loma Salamander (Bolitoglossa colonnea), a limited range taxon occurring only in portions of Costa Rica and Panama;.Central American Worm Salamander (Oedipina elongata), who inhabits very moist habitats; Cienega Colorado Worm Salamander (Oedipina uniformis, NT), a limited range taxon found only in parts of Costa Rica and Panama, including higher elevation forests than the mangroves; Limon Worm Salamander (Oedipina alfaroi, VU), a restricted range caecilian found only on the Atlantic versant of Costa Rica and extreme northwest Panama. Caecilians found in the ecoregion are represented by: La Loma Caecilian (Dermophis parviceps), an organism found in the Atlantic versant of Panama and Costa Rica up to elevation 1200 metres
- William G. D'Arcy, D. Mireya and A. Correa. 1985. The Botany and Natural History of Panama, Universidad de Panamá. , 455 pages
- C.Michael Hogan & World Wildlife Fund. 2013. "Mesoamerican Gulf-Caribbean mangroves".. Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Peter Saundry
Morelet's crocodiles live primarily in freshwater areas such as swamps and marshes and can also be found in forested riparian habitats. Recently, C. moreletii has even been found residing in coastal brackish water. Juveniles prefer denser cover for protection, and adults tend to aestivate in burrows during the dry season.
Habitat Regions: temperate ; tropical ; terrestrial ; freshwater
Terrestrial Biomes: forest
Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water
Wetlands: marsh ; swamp
Other Habitat Features: riparian
Habitat and Ecology
Morelet's crocodiles vary in diet according to their age and size. Juveniles eat small invertebrates and fish. Sub adults feed on aquatic snails, fish, small birds, and mammals. Adults feed on larger prey, including birds, fish, lizards, turtles, and domestic animals such as dogs. They can also become cannibalistic in times of low food, eating newborns. Crocodylus moreletii is generally shy around humans, but larger ones may attack if provoked.
Animal Foods: birds; mammals; amphibians; reptiles; fish; carrion ; insects; mollusks; aquatic crustaceans
Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore )
- Rainwater, T., B. Adair, S. Platt, T. Anderson, G. Cobb. 2002. Mercury in Morelet's Crocodile Eggs from Northern Belize. Archives of Environmental Contamination and Toxicology, 10.1007/s00244-001-0020-7: 319-324.
While not much information is known about the specific impact of the Morelet's crocodiles on their ecosystem, they do share many similar traits with the American crocodile, such as the role of primary carnivore in the ecosystem, thus affecting nutrient dispersal and ecosystem dynamics.
- Richardson, D. C. J. 2003. "The American Crocodile" (On-line ). Accessed 04/09/03 at http://www.env.duke.edu/wetland/american.htm.
While Morelet's crocodiles tend to be dominant predators in their communities, their eggs and young often fall prey to older juveniles, larger mammals, snakes, wading birds, and gulls. A key protection from predators is their tough hide and their loud vocal cries. Larger individuals are potentially preyed upon by humans and jaguars.
- rats (Rattus)
- wading birds (Ardeidae)
- large snakes (Serpentes)
- gulls (Larus)
- jaguars (Panthera onca)
Life History and Behavior
Juveniles communicate through vocalization (known as barking) when born, though not much information is known about specific social communication. They tend to follow the basic patterns of all Crocodylus, which are the most vocal of all reptiles; their calls tend to differ depending on age, sex and situation. They may share the similar habit of the American crocodile, whose young are not as vocal as other species, which may be a response to high hunting pressures, resulting in a rapid adaptation for survival.
Scales covering most of the head and parts of the body are equipped with integumentary sense organs (ISO's) that perform a number of tasks, such as detecting pressure, salinity, and vibrations.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
When born, juveniles generally weigh about 31.9 grams. Morelet's crocodiles have three main life stages, classified through their length: juveniles < 100 cm, sub adults 100-150 cm, and adults >150 cm. Not much information is known about the specific life cycle of this crocodile. As in all crocodilians, however, sex is determined by the incubation temperature of the eggs.
Development - Life Cycle: temperature sex determination
- Liesegang, D. A., D. K. Baumgartner. 2002. "Rickets in juvenile Morelet's Crocodile" (On-line ). Accessed 03/18/03 at http://www.research-projects.unizh.ch/vet/unit51100/area217/p2373.htm.
Because they are both rare and difficult to study, not much is known about specific life cycles. Morelet's crocodiles that are bred in captivity appear to have a slightly longer lifespan (up to 80 years) than those that live in the wild (50 to 65 years). Females appear to live slightly longer than males.
Status: captivity: 80 (high) years.
Status: wild: 50 to 65 years.
Status: wild: 60 years.
Status: captivity: 55 to 70 years.
Status: captivity: 65 years.
- Stafford, P. J., J. R. Meyer. 2000. A Guide to the Reptiles of Belize. London: Natural History Museum of London.
Lifespan, longevity, and ageing
Not much information is known about particular mating habits between males and females, although they appear to follow some of the same mating habits (such as being polygynous) of the American crocodile (Crocodylus acutus). Probably large males dominate the other males in their area, and females prefer to mate with the dominant males.
Mating System: polygynous
Oviposition for crocodiles living on the Yucatan primarily takes place in Chiapas between April and June. Crocodylus moreletii is unique because it is the only crocodile known to be exclusively mound nesting, laying between 20 and 40 eggs in nests that are approximately 3 m wide by 1 m high. Some nests have been found containing more than one female's eggs.
At hatching time, two to three months after laying the eggs, female Morelet's crocodiles have been known to carry eggs to water areas and crack them open. Reproductive rates are generally high among C. moreletii because of the relatively early maturation of the females. Not much information is available about the specific behavior of juveniles or the fertilization process. Research is currently being conducted in these areas.
Breeding interval: Morelet's crocodiles breed once a year directly before the rainy season.
Breeding season: Oviposition takes place between April and June. The incubation period lasts 2 to 3 months.
Range number of offspring: 20 to 40.
Range age at sexual or reproductive maturity (female): 7 to 8 years.
Average age at sexual or reproductive maturity (female): 7 years.
Range age at sexual or reproductive maturity (male): 7 to 8 years.
Average age at sexual or reproductive maturity (male): 7 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Female Morelet's crocodiles guard their nests until the eggs are ready to hatch. Studies among captive Crocodylus moreletii show females will respond to newborn vocalizations and open the nests. Males and females will also fiercely defend hatchlings against larger juveniles or other predators. Not much information is known about further interaction between juveniles and parents.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female); pre-independence (Protecting: Male, Female)
- Britton, A. 2002. "Crocodilian Species-Morelet's Crocodile (Crocodylis Moreletii)" (On-line ). Crocodilian Species List. Accessed 03/18/03 at http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csl.html.
- Platt, S. G., J. B. Thorbjarnason. November 2000. Population Status and Conservation of Morelet's Crocodile. Biological Conservation, 96/1: 21-29.
Molecular Biology and Genetics
Barcode data: Crocodylus moreletii
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Crocodylus moreletii
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
Due to their valuable hide, Morelet's crocodiles were hunted almost to extinction through the years 1940 to 1950. Under the Mexican Wildlife Protection Act, hunting them became illegal and their numbers have steadily risen, although illegal poaching and habitat loss continue to threaten the animal. To counteract this, Mexico has begun breeding Morelet's crocodiles in captivity. However, some individuals have escaped to form feral populations outside of their regular breeding zones, creating a problem for the populations of American crocodile, which must compete with this newly-invasive species.
Now primary focus remains in the development of sustainable use programs, such as commercial farming. More general knowledge about the species is required first, however. Status in the south of Belize is unknown; reports suggest the species is widely distributed in the Mexican states of Tabasco, Chiapas, Yucatan and Quintana Roo, and their situation in the interior of Guatemala is unknown. There remains little information on both specific numbers and general behavior patterns needed to judge their actual status throughout most of its range.
Morelet's crocodiles are listed as Endangered under the U.S. Endangered Species Act, and are included in Appendix I of the CITES Treaty. The IUCN rates the species as "Lower Risk", but this rating would revert to Threatened or Endangered if ongoing conservation efforts were ended.
US Federal List: threatened
CITES: appendix i
IUCN Red List of Threatened Species: lower risk - conservation dependent
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Data Deficient
- 1990Endangered(IUCN 1990)
- 1988Endangered(IUCN Conservation Monitoring Centre 1988)
- 1986Endangered(IUCN Conservation Monitoring Centre 1986)
Status: Delisted due to Recovery
Date Listed: 06/02/1970
Lead Region: Foreign (Region 10)
For most current information and documents related to the conservation status and management of Crocodylus moreletii , see its USFWS Species Profile
Tests on wild eggs of this species show that exposure to chemical pollutants including pesticides may be a significant threat to the long-term survival of some populations (Wu et al. 2000).
Relevance to Humans and Ecosystems
Although generally shy, as with any crocodile, C. moreletii has been known to bite humans if provoked.
Negative Impacts: injures humans (bites or stings)
- Matthews, D. 1995. "Four Faces of Mexico; in the Yucatan, a wild and seldom visited wetland". Washtington Post, 01908286: E01.
Unlike most other species of crocodilian, Morelet's crocodiles have no bony plates (called osteoderms) in their skin. This makes the skin more valuable as leather, and has motivated over-hunting.
Also, studies of the levels of mercury within the eggs of Morelet's crocodiles in Belize has also led to clues about biological contamination there.
Positive Impacts: body parts are source of valuable material; research and education
Morelet's crocodile (Crocodylus moreletii), also known as the Mexican crocodile, is a modest sized crocodilian found only in fresh waters of the Atlantic regions of Mexico, Belize and Guatemala. It usually grows to about 3 metres (9.8 ft) in length. It is a Least Concern species.
Taxonomy and etymology
Morelet's crocodile was discovered in Mexico in 1850 and named after the French naturalist who made the discovery, P.M.A. Morelet (1809–1892). It was long confused with the American and Cuban crocodiles because of similar characteristics. It was not realized that they were a separate species until the 1920s.
Morelet's crocodile has a very broad snout with 66 to 68 teeth when they are fully mature. They are dark grayish-brown in color with dark bands and spots on the body and the tail. This is similar to other crocodiles, like the American crocodile, but the Morelet is somewhat darker. Juvenile crocodiles are bright yellow with some dark bands. The crocodile’s iris is silvery brown. They have four short legs, giving them a rather sprawling gait, and a long tail, which is used for swimming. The hind feet of the crocodiles are webbed. They have very explosive capabilities because of their strong muscles and are fast runners.
Morelet’s crocodile is small compared to several other crocodiles. The males can become larger than the females. The adult crocodile averages 2.2–3 m (7.2–9.8 ft) in length with a maximum reported length of 4.3 m (14 ft) Body mass in this species is often around 38–58 kg (84–128 lb), though is likely much more in large individuals. Overall, this species is similar to the Cuban and the larger American crocodiles in appearance.
Distribution and habitat
Morelet's crocodile can be found in freshwater habitats in Central America and along the Gulf of Mexico stretching through Belize, Guatemala, and to Mexico. The Belizean pine forests are an example of the type of ecoregion in which they occur. In their freshwater habitats, they prefer isolated areas that are secluded. This species of crocodile can mainly be found in freshwater swamps and marshes, which are located inland, and in large rivers and lakes. Both of these habitats are forested to help add cover.
The Morelet can also be found along the coast in brackish waters and the grassy savannas on the Yucatán Peninsula. These crocodiles become much more distributed during the rainy seasons when flooding occurs and it is easier for them to move elsewhere.
Juvenile crocodiles live in very dense cover to protect them from other predators that might be in the area and will remain there until they become older and able to fend for themselves. Adult crocodiles are known to dig out burrows during dry seasons in their area. The range of this crocodile can overlap with the American crocodile, which can sometimes lead to them being confused with one another.
Recently, the Morelet's crocodile has been introduced into the Rio Grande (Rio Bravo in Mexico). Several newspaper outlets on the Mexican side of the border report of reptiles inhabiting the river appearing not to be the American alligator which is native to Texas, but the Morelet's crocodile which is native to Tamaulipas from San Fernando southward. Making a new danger for people who swim or illegally cross into the United States. Crocodiles have been seen in the cities of Matamoros, Reynosa and as far north as Nuevo Laredo. The sightings have prompted several municipal police departments to put up signs warning people about entering the river.
Biology and behavior
Hunting and diet
Morelet's crocodiles prey on small mammals, birds, and other reptiles. These small mammals can include domesticated animals like cats and dogs. Juvenile crocodiles feed largely on fish and insects until they become bigger and more capable of bringing down larger prey. Crocodiles have been known to be cannibalistic, this includes eating their young.
Breeding usually takes place between April and June and the eggs or laid before the start of the rainy season. Morelet's crocodiles are unique among North American crocodiles in that they build mound nests only, and not mound and hole nests. These mound nests are about 3 metres (9.8 ft) wide and 1 metre (3.3 ft) high and can be found near the water or on floating vegetation. A female crocodile can lay between 20 and 45 eggs and nests have been found containing eggs from more than one female. The eggs are buried and the nests are guarded by females that protect their unborn young from predators. The eggs usually hatch after 80 days of incubation and hatchlings are normally about 17 centimetres (6.7 in) long. After the eggs have hatched the female crocodile will carry her young to the water where they are protected by both parents and will later leave them to fend for themselves.
Morelet's crocodile has long been threatened by habitat destruction and illegal hunting. Both of these factors have significantly lowered their populations. It was hunted for its hide during the 1940s and 1950s because high quality leather can be made from their skins. Crocodile leather can be used to make wallets, coats and shoes.
One of the key protectors of crocodiles today is the CSG, or Crocodile Specialist Group, started in 1971. This is a worldwide organization of biologist and other professions coming together to conserve the 23 species of alligators and crocodiles. The CSG monitors all trading of crocodile skins and helps determine if the skins are legal or were illegally taken. When this organization started, all of the crocodilian species were either threatened or endangered. Today, those numbers have greatly changed.
“By 1996 one third of the crocodilian species were abundant enough to support regulated annual harvests, another third were no longer in danger of extinction, but the final one third of the species still remain endangered.”
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