American crocodile
(Crocodaylus acutus)
The American crocodile is a species of crocodilian found in the Neotropics. It is the most widespread of the
four extant species of crocodiles from the Americas. Populations occur from the Atlantic and Pacific coasts
of southern Mexico to South America as far as Peru and Venezuela. It also lives on many of the Caribbean
islands such as Cuba, Jamaica, Hispaniola and Grand Cayman.
Conservation status
Vulnerable
Scientific classification
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Kingdom:
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Animalia
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Phylum:
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Chordata
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Class:
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Reptilia
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Order:
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Crocodilia
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Family:
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Crocodylidae
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Genus:
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Crocodylus
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Specie:
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Crocodylus acutus
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Description
Like all crocodilians, the American crocodile is a quadruped, with four short, stocky legs, a long, powerful
tail and a scaly hide with rows of ossified scutes running down its back and tail. Its snout is elongated and
includes a strong pair of jaws. Its eyes have nictitating membranes for protection along with lachrymal
glands, which produce tears.
The nostrils, eyes, and ears are situated on the top of its head, so the rest of the body can be concealed
underwater for surprise attacks. Camouflage also helps it prey on food. The snout is relatively longer and
narrower than that of the American alligator (Alligator mississippiensis), although broader on average than
that of the Orinoco crocodile (C. intermedius). American crocodiles are also paler and more grayish than the
relatively dark-hued alligator. This crocodile species normally crawls on its belly, but it can also "high
walk". Larger specimens can charge up to nearly 10 mph (16 km/h). They can swim at as much as 20 mph
(32 km/h) by moving their bodies and tails in a sinuous fashion, but they cannot sustain this speed.
The American crocodile is sometimes confused with the smaller, Central American Morelet's crocodile, a
smaller species that is native to Mexico.
Distribution and habitat
Crocodylus acutus is the most widespread of the four extant species of crocodiles from the Americas. It
inhabits waters such as mangrove swamps, river mouths, fresh waters, and salt lakes, and can even be found at
sea, hence its wide distribution throughout the Caribbean islands, southern Florida, the Greater Antilles,
southern Mexico, Central America, and the South American countries of Colombia and Ecuador. The American
crocodile is especially plentiful in Costa Rica. One of its largest documented populations is in Lago
Enriquillo, a hypersaline lake in the Dominican Republic. The species has also been recorded from Jamaica.
American crocodiles have recently been sighted in Grand Cayman, leading experts to believe the species may
be swimming from Cuba (which is home to a massive American crocodile population) and slowly repopulating
Grand Cayman. In addition, an American crocodile/Cuban crocodile hybrid was recently discovered in the
Cancun area. The crocodile likely originated in the Zapata Swamp of Cuba (the only place where these wild
hybrids exist) and swam to the Yucatán Peninsula. Their saline tolerance also allowed the American crocodile
to colonize limited portions of the United States (Puerto Rico and extreme southern Florida). Contrary to
popular misinformation, the presence of the American alligator is not the reason the American crocodile was
unable to populate brackish waters north of Florida, but rather the climate.
American crocodiles, unlike American alligators, are extremely susceptible to cold temperatures and live
exclusively within tropical waters. During 2009, unusually cold weather in southern Florida resulted in the
deaths of about 150 wild American crocodiles, including a well-known crocodile which inhabited Sanibel
Island far north of their natural range.
American crocodiles in the United States coexist with the American alligator, and are primarily found south
of the latitude of Miami, in Everglades National Park, Florida Bay, Biscayne Bay, and the Florida Keys.
A sizable population occurs near Homestead, Florida, at the Turkey Point Nuclear Generating Station.
Some individuals wander northward to warm summer waters and have been sighted in Sarasota County and Palm
Beach County. In the summer of 2008, a crocodile was captured in the surf on Isle of Palms, South Carolina.
In 2013, a 700-pound crocodile was captured in Tarpon Springs, Florida. Florida Fish and Wildlife
Conservation Commission program staff note that the crocodile was not weighed to be 700 lbs. The weight was
estimated by the Nuisance Alligator Trapper who inadvertently caught the animal using a baited hook.
American crocodiles of similar lengths have been accurately weighed at 450-500 lbs.
The American crocodile is saltwater-tolerant and have thus been capable of colonizing a multitude of islands
within the Caribbean islands and on some coastal Pacific islands as well. They coexist with the rather
smaller spectacled caiman within Central America. The only other crocodiles present within the American
crocodile's range are two species smaller than this species on average: the critically endangered Cuban
crocodile, along with the Morelet's crocodile in southern Mexico and Guatemala.
Behavior
American crocodiles are more susceptible to cold than American alligators. While an American alligator can
survive in water of 7.2 °C (45.0 °F) for some time, an American crocodile in that environment would become
helpless and drown. American crocodiles, however, have a faster growth rate than alligators, and are much
more tolerant of salt water.
Cleaning symbiosis involving the American crocodile as client has been described. Unlike the Old World
crocodiles, which are sometimes cleared of parasites by birds, the American crocodile relies more on fish for
parasite removal.
Reproduction
American crocodiles breed in late fall or early winter, engaging in drawn-out mating ceremonies in which
males emit very low frequency bellows to attract females. Body size is more important than age in
determining reproductive capabilities, and females reach sexual maturity at a length of about 2.8 m
(9.2 ft). In February or March, gravid females will begin to create nests of sand, mud, and dead vegetation
along the water's edge. Nest location is crucial, and with the correct amount of vegetation, the eggs will
develop within a small temperature range. Because sex determination is temperature-dependent in
crocodilians, slight aberrations in temperature may result in all-male or all-female clutches, which would
possibly harm the health of the population. About one month later, when it is time to lay, the female will
dig a wide hole diagonally into the side of the nest and lay 30 to 70 eggs in it, depending on her size.
After laying, the female may cover the eggs with debris or leave them uncovered. The white, elongated eggs
are 8 cm (3.1 in) long and 5 cm (2.0 in) wide and have a number of pores in the brittle shell. During the
75- to 80-day incubation period, the parents will guard the nest, often inhabiting a hole in the bank
nearby. Females especially have been known to guard their nests with ferocity. But in spite of these
precautions, crocodile eggs sometimes fall prey to raccoons (Procyon sp.) (arguably the most virulent
natural predator of crocodilian nests in the Americas), coatis, foxes, skunks or other scavenging mammals
(even coyotes (Canis latrans) in Mexico and American black bears (Ursus americanus)) in south Florida), as
well as large predatory ants, crabs and vultures. In Panama, green iguana (Iguana iguana) were seen to dig
up and prey on American crocodile eggs occasionally, although in several cases were caught by the mother
crocodile and subsequently consumed. Crocodilian eggs are somewhat brittle, but softer than bird eggs.
Young of this species hatch after 75-80 days.
This species exists mostly in tropical areas with distinct rainy seasons, and the young hatch near the time
of the first rains of the summer (July-August), after the preceding dry season and before the bodies of
water where they live flood. In this stage of development of their young, mother crocodiles exhibit a unique
mode of parental care. During the hatching process, when the young crocodiles are most vulnerable to
predation, they will instinctively call out in soft, grunt-like croaks. These sounds trigger the female to
attend to the nest, uncovering the eggs if they have been covered. Then she will aid the hatchlings in
escaping their eggs and scoop them up with her mouth, carrying them to the closest water source.
The hatchlings, which are 24 to 27 cm (9.4 to 10.6 in) in length, have been reported to actively hunt prey
within a few days of hatching. It is not uncommon for the mother to care for her young even weeks after they
have hatched, remaining attentive to their calls and continuing to provide transportation. About five �Ǜ�Ǜ0l����8ț�Ǜs�Ǜhem, of
course, will not survive, being preyed upon by several types of raptorial birds and larger fishes
(e.g. barred catfish (Pseudoplatystoma fasciatum), Atlantic tarpons (Megalops atlanticus), common snook
(Centropomis undecimalis) and lemon sharks (Negaprion brevirostris)), boa constrictors (Boa constrictor),
black spiny-tailed iguana (Ctenosaura similis), spectacled caimans, as well as raccoons. Those that do
survive the early stages of life will grow rapidly, feeding on insects, fish and frogs. Additionally, some
young crocodiles reportedly will feed on each other.
Zoológico de Vallarta A. C.
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