American crocodile (Crocodylus acutus)American crocodiles (Crocodylus acutus) basking in the sun in Costa Rica. Usually solitary, the reptiles bask for most of the day and then enter the water during the evening to hunt.(more)American crocodile, (Crocodylus acutus), moderately large species of crocodile inhabiting forests and freshwater environments, as well as brackish and marine intertidal environments, in Florida, Central America, northern South America, and several Caribbean islands. This species has the largest geographic range of any crocodile in the New World. It can be found from Mexico’s Pacific coast south to the northernmost part of Peru and from southern Florida in the U.S. southward through Cuba, Jamaica, Haiti, and the Dominican Republic and through Central America to northern Colombia and Venezuela. Although American crocodiles prefer small vertebrates as prey, they have been known to attack people on rare occasions. Nevertheless, they are less aggressive than other New World crocodilians, such as the American alligator (Alligator mississippiensis).

　　Natural history

　　American crocodile (Crocodylus acutus)Head of an American crocodile (Crocodylus acutus). The species has 30–40 teeth in the upper jaw and 28–32 in the lower jaw. When the mouth is closed, several upper and lower teeth are visible outside the mouth, the most prominent commonly being the fourth tooth from the front in the lower jaw.(more)The American crocodile is a sexually dimorphic species: males grow significantly larger than females. The largest males may be 5–6 meters (16.4–19.7 feet) long, whereas females do not exceed 3.5 meters (11.5 feet) in length. There are reports of 7-meter- (22.6-foot-) long males and 4.4-meter- (14.4-foot-) long females, but these are unconfirmed. Adults are quite massive, weighing between 220 and 450 kg (485 and 992 pounds), though the largest males may weigh 900 kg (1,984 pounds) or more. Adults are grayish green on the top and sides, with lighter coloration underneath. In contrast, juveniles are brownish and have more-pronounced spotting or banding. The head is triangular, with a snout that tapers to a small bulb containing the nostrils. The scales of American crocodiles are thick, with long rows of small bony plates that extend down the length of the back and tail. However, according to some sources, the species is less armored than other crocodilians. The American crocodile has 30–40 teeth in its upper jaw and 28–32 in its lower jaw. When the mouth is closed, several upper and lower teeth are visible outside the mouth, the most prominent commonly being the fourth tooth from the front in the lower jaw.

　　American crocodiles are apex predators throughout their range. Usually solitary, the reptiles bask in the sun for most of the day and then enter the water during the evening to hunt. During the warmest months, many crocodiles dig burrows to hide from the day’s heat. Adults have a broad diet that ranges from insects and small invertebrates, such as crabs, to fishes, turtles, frogs, birds, and mammals (including dogs). Attacks on people are rare, and they are often provoked. Young crocodiles prey on smaller items, such as small fish and crustaceans. Adults have no natural enemies other than people who hunt them. However, the eggs are eaten by raccoons, skunks, and other small mammals, and juveniles sometimes fall prey to large fishes, feral cats, and even adult crocodiles (see cannibalism, animal).

　　The species is largely polygynous (that is, a single male mates with several females in one season). However, some females have been shown to use parthenogenesis to reproduce. (According to evidence first found in 2023, American crocodiles are the only known parthenogenetic crocodilians.) For sexually reproducing individuals, the mating process commences with two months of courtship at the beginning of the dry season, in January and February. During this period, males make roaring vocalizations to entice females and compete with one another for territories and breeding partners. After mating takes place, a female crocodile constructs a nest of decomposing vegetation and mud, and some three to four weeks after mating she deposits a clutch of 30 to 60 eggs. The eggs are guarded by the female and warmed for about 85 days by the heat generated by the decomposing vegetation. Hatching starts in late July. The sex of the young is determined by the incubation temperature: higher numbers of females are produced in environments below about 29.4 °C (85 °F), and higher numbers of males emerge if the temperature nears 32.2 °C (90 °F).

　　As they emerge, newly hatched young are helped from the nest and brought to the water by their mother. The mother may remain with her young for only a few days before leaving them to fend for themselves. Hatchling and juvenile mortality is quite high. Indeed, only about 25 percent of young crocodiles survive until age 4. Both sexes become sexually mature when they reach lengths of between 1.8 and 2.4 meters (5.9 and 7.9 feet) long, which occurs between ages 8 and 10. The typical life span for American crocodiles is between 50 and 70 years in the wild, though some may live as long as 100 years. The crocodile’s life span in captivity is about 45 years.

　　Conservation status The International Union for Conservation of Nature and Natural Resources (IUCN) has considered the American crocodile to be a vulnerable species since 1996. Between 1982 and 1994 the IUCN listed the animal as an endangered species. The American crocodile was hunted throughout its range for its hide, which is made into leather products, and one study showed that it experienced a precipitous decline between 1930 and the early 1970s, before it became one of the first species placed on the U.S. endangered species list (see Endangered Species Act). While progress has been made in recovering American crocodile populations in much of the animal’s range—including in Cuba, Costa Rica, Mexico, Venezuela, and the U.S.—population studies estimate that the species is made up of only 5,000 adults worldwide. (American crocodiles remain listed as an endangered species under the U.S. Endangered Species Act.) The species is still harvested, but much of the hide is taken from captive-bred populations on farms and ranches in Cuba, Honduras, and Colombia. Nevertheless, commercial harvesting has not offset losses from illegal hunting and other forms of mortality. Some American crocodiles are victims of habitat loss and degradation, as sea levels rise and mangrove swamps in their native range are converted to aquaculture areas; others drown in fishing nets. Furthermore, the species’ distinctiveness is threatened by hybridization: it can interbreed with the Cuban crocodile (Crocodylus rhombifer) on Cuba’s Zapata peninsula and with Morelet’s crocodile (C. moreletii) in eastern Mexico, Guatemala, and Belize.

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