Morelet’s crocodile

Morelet’s crocodile, (Crocodylus moreletii), medium-sized crocodile species inhabiting forests and wetlands and coastal freshwater and brackish waterways in Belize, northern Guatemala, and states in Mexico bordering the Gulf of Mexico. The species is distinguished from others by the shape of its snout. Unlike other crocodiles, which have triangular snouts, Morelet’s crocodile has a snout that is more alligator-like; that is, it is blunted and rounded. Morelet’s crocodile can be aggressive toward people. Although reports of attacks are rare compared with those of other, larger crocodilians, nearly three dozen attacks on people were documented between 2012 and 2022 in Tamaulipas state in Mexico.

Natural history

Most adult Morelet’s crocodiles grow to lengths of 1.5–3 meters (4.9–9.8 feet) and weigh roughly 50 kg (110.2 pounds). However, the largest adults can be as long as 4.5–4.7 meters (14.8–15.4 feet) and as large as 58.1 kg (128.1 pounds). Whereas there is little size difference between small and average-sized adults, the largest males have substantially longer heads and bodies than those of the largest females (see also sexual dimorphism). The body of Morelet’s crocodile is grayish brown, and many have dark bands and spots on the top and sides of the body and on the tail and a lighter-colored underside. The crocodile has silvery-brown eyes, its snout is broader and rounder than those of most crocodiles, and the scales on its back and tail have smoother keels than those of most other crocodilian species. The body coloration of juveniles is similar to that of adults, with more pronounced black banding that alternates with yellowish banding along the length of the tail.

Morelet’s crocodile is an apex predator that spends most of its day basking in the sun before becoming more active toward the evening. It lurks just under the water’s surface waiting for its prey, with adults seeking out larger fishes, birds, other reptiles, and even dogs that venture too close to the water’s edge. Juveniles consume smaller-sized prey, such as snails and other invertebrates and smaller fishes. Adult and juvenile Morelet’s crocodiles can also consume carrion or their smaller brethren (see also cannibalism, animal). Morelet’s crocodile eggs, hatchlings, and juveniles are consumed by snakes, birds, and larger mammals, and adults sometimes fall victim to constrictor snakes and jaguars and also sometimes are hunted by people.

Curiously, given that the geographic ranges of both species overlap in the southern part of the range of the Morelet’s crocodile, there are few conflicts between Morelet’s crocodiles and American crocodiles (Crocodylus acutus). They are largely separate from one another, and there is little evidence of competition. Where both species co-occur, Morelet’s crocodiles tend to inhabit inland freshwater environments, whereas American crocodiles prefer brackish, coastal ones. In addition, there is evidence of interbreeding between the two.

The species follows a polygynous mating system (wherein one male may breed with multiple females), and it reproduces during the dry season between April and July. Breeding females build large nests, as wide as 3 meters (9.8 feet) across, out of soil, decomposing vegetation, and cast-off plant debris before laying as many as 40–50 eggs in a clutch. The eggs hatch between August and September, and young are moved to the water by their mother in her jaws. Young are guarded for a time by their mother and their father before they disperse. Morelet’s crocodiles reach sexual maturity between ages 7 and 8, roughly the same time that they reach 1.5 meters (4.9 feet) in length. They may live as long as 50–65 years in the wild and as long as 80 years in captivity (see also life span).

Conservation status

Morelet’s crocodile has been listed as a species of least concern by the International Union for Conservation of Nature and Natural Resources (IUCN) since 2012. This was not always the case, however. Morelet’s crocodile was hunted extensively for its hide during the middle of the 20th century, which led to restrictions and hunting prohibitions on the species during the 1970s, although illegal hunting continued into the 1980s and ’90s. The IUCN first assessed Morelet’s crocodile in 1982, and it was listed as an endangered species until 1996. As of the 2020s, hunting is rare, and some 80,000–100,000 adults are thought to live in the wild.

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Ecologists note that the species is thriving, but they have identified a few threats that could affect Morelet’s crocodile populations in the long term. Chief among these is contamination from heavy metals, such as mercury and copper, which are associated with tailings (waste materials) from dam construction and runoff from agricultural areas and waste dumps. The sensitivity of Morelet’s crocodiles to these chemicals has led to their use as a bioindicator species (that is, a proxy that can be used to assess the environmental health of an ecosystem) in parts of the Yucatán Peninsula. The species is persecuted in some areas of Mexico, where conflicts between human beings and crocodiles and crocodile attacks have increased during the 2010s and ’20s.