Misplaced Pages

#724275

102-520: Crocodile Lake National Wildlife Refuge was once entirely platted for residential development; however, accumulated deposits of dredge-spoils on the bayside of North Key Largo became an important nesting area for some of the country's remaining American crocodiles which have recovered in recent years from a low, in 1975, of approximately 200 in population size. The American crocodile had nearly been extirpated by hunting for export of its hide as an exotic leather. The government took protective action and listed

204-462: A mourning dove and a bare-tailed woolly opossum in its stomach. In Florida, bass , tarpon and especially mullet , large crabs , snakes , mammals that habit the riparian and coastal regions of the Everglades , such as opossums and raccoons appeared to be the primary prey of American crocodiles. In Southern Florida, it was found that American Crocodiles rely on marine food sources 65% of

306-508: A 1.5 m (4 ft 11 in) crocodile of its own species, a turtle shell and peccary hooves. It was noted that historically in Mexico that, among several local farmers, the capturing of livestock by American crocodiles has been a source of some conflict between humans and American crocodiles and large adults occasionally can become habitual predators of goats, dogs, pigs and cattle. In Quintana Roo, Mexico , most prey that could be determined

408-521: A Burmese named "Baby" was the heaviest snake recorded in the world at the time at 182.8 kg (403 lb), much heavier than any wild snake ever measured. Her length was measured at 5.74 m (18 ft 10 in) circa 1999. The minimum size for adults is 2.35 m (7 ft 9 in). Dwarf forms occur in Java , Bali , and Sulawesi , with an average length of 2 m (6 ft 7 in) in Bali, and

510-499: A Burmese python was captured in Florida that weighed 98 kg (215 lb) and had a length of 5.5 m (18 ft); it contained a record 122 developing eggs. In July 2023, local hunters captured and killed a 5.8 m (19 ft) long Burmese python that weighed 57 kg (125 lb) in Florida's Big Cypress National Preserve. Burmese pythons are mainly nocturnal rainforest dwellers. When young, they are equally at home on

612-818: A Florida zoo escaped its cage and started a fight with a large male American alligator in a bordering pen, and was killed. Conversely, there is one confirmed case of an American crocodile preying on a sub-adult American alligator in the wild in Florida. American alligators and American crocodiles do not often come into conflict in the wild, due largely to habitat partitioning and largely separate distributions. There are several records of American crocodiles killing and eating spectacled caimans in South America. Areas with healthy American crocodile populations often hold only limited numbers of spectacled caimans, while conversely areas that formerly held American crocodiles but where they are now heavily depleted or are locally extinct show

714-568: A faster growth rate than alligators, and are much more tolerant of saltwater. Unlike other crocodiles, the American crocodile uses acoustic signals to communicate. Crocodile communication is centered on short-distance communications during courtship and hatching. Cleaning symbiosis involving fish and the American crocodile has been described. American crocodiles are apex predators , and any aquatic or terrestrial animal they encounter in freshwater , riparian and coastal saltwater habitats

816-464: A few times again since then and is now an annual event over the duration of ten days. Recently, in 2023, it resulted in 209 pythons removed by 1,050 participants. A study from 2017 introduced a new method for identifying the presence of Burmese pythons in southern Florida; this method involves the screening of mosquito blood. Since the introduction of the Burmese python in Florida, mosquito communities use

918-578: A growth of caiman numbers, due to less competition as well as predation. In areas of Cuba where the two species coexist, the smaller but more aggressive Cuban crocodile is behaviorally dominant over the larger American crocodile. In Mexico , some Morelet's crocodile individuals have escaped from captivity, establishing feral populations and creating a problem for the populations of American crocodile, which must compete with this invasive species. Burmese pythons Python molurus bivittatus Kuhl , 1820 The Burmese python ( Python bivittatus )

1020-995: A maximum of 2.5 m (8 ft 2 in) on Sulawesi. Wild individuals average 3.7 m (12 ft) long, but have been known to reach 5.79 m (19 ft 0 in). In both their native and invasive range they suffer from Raillietiella orientalis (a pentastome parasitic disease). The Burmese python occurs throughout Southern and Southeast Asia, including eastern India , southeastern Nepal , western Bhutan , southeastern Bangladesh , Myanmar , Thailand , Laos , Cambodia , Vietnam , northern continental Malaysia , and southern China in Fujian , Jiangxi , Guangdong , Hainan , Guangxi , and Yunnan . It also occurs in Hong Kong , and in Indonesia on Java , southern Sulawesi , Bali, and Sumbawa . It has also been reported in Kinmen . It

1122-411: A model species for digestive physiology. Its sit-and-wait hunting style is characterized by long fasting periods in between meals, with Burmese pythons typically feeding every month or two, but sometimes fasting for as long as 18 months. As digestive tissues are energetically costly to maintain, they are downregulated during fasting periods to conserve energy when they are not in use. A fasting python has

SECTION 10

#1732844887725

1224-590: A prey animal with its sharp teeth, then wraps its body around the animal to kill it through constriction . The python then swallows its prey whole. It is often found near human habitation due to the presence of rats, mice, and other vermin as a food source. However, its equal affinity for domesticated birds and mammals means it is often treated as a pest. In captivity, its diet consists primarily of commercially available appropriately sized rats, graduating to larger prey such as rabbits and poultry as it grows. As an invasive species in Florida, Burmese pythons primarily eat

1326-584: A rapid growth rate, and can exceed 2.1 m (6 ft 11 in) in length in a year if power fed. However this may cause health issues in the future. By age four, they will have reached their adult size, though they continue growing very slowly throughout their lives, which may exceed 20 years. Although the species has a reputation for docility, they are very powerful animals – capable of inflicting severe bites and even killing by constriction. They also consume large amounts of food, and due to their size, require large, often custom-built, secure enclosures. As

1428-496: A reduced stomach volume and acidity, reduced intestinal mass, and a 'normal' heart volume. After ingesting prey, the entire digestive system undergoes a massive re-modelling, with rapid hypertrophy of the intestines, production of stomach acid, and a 40% increase in mass of the ventricle of the heart to fuel the digestive process. During digestion, the snake's oxygen consumption rises drastically as well, increasing with meal size by 17 to 40 times its resting rate. This dramatic increase

1530-505: A result of these high-mortality freezes. They have carried Raillietiella orientalis , a pentastome parasitic disease, with them from Southeast Asia. Other reptiles in Florida have become infested, and the parasite appears to have become endemic. In April 2019, researchers captured and killed a large Burmese python in Florida's Big Cypress National Preserve . It was more than 5.2 m (17 ft) long, weighed 64 kg (140 lb), and contained 73 developing eggs. In December 2021,

1632-490: A result, some are released into the wild, and become invasive species that devastate the environment. For this reason, some jurisdictions (including Florida, due to the python invasion in the Everglades ) have placed restrictions on the keeping of Burmese pythons as pets. Violators could be imprisoned for more than seven years or fined $ 500,000 if convicted. Burmese pythons are opportunistic feeders; they eat almost any time food

1734-513: A second (uncollared) woodrat. The python also turned out to be the first vouchered (verified by a specimen or photograph) occurrence of its species found wild in the Florida Keys. However, over the following year, another half-dozen pythons were found after they were killed by traffic on roads in the same area. The appearance of numbers of Burmese pythons in North Key Largo was forewarning of

1836-730: A serious new threat to the survival, not just of the rare Key Largo Woodrat and Cotton Mouse, but also to another three federally endangered mammals found only in the Florida Keys: the Key Deer, Silver Rice Rat and Keys Marsh Rabbit are all found only in the Lower Florida Keys (on Big Pine Key and a few other islands further down the archipelago). Though pythons and other constrictors (especially boa constrictors) do take other prey, most have special adaptations for detecting and capturing warm-blooded prey (mammals and birds), even in total darkness. And

1938-516: A sinuous fashion, but they cannot sustain this speed. Adults have a uniform grayish-green coloration with white or yellow undersides, while juveniles have dark cross-banding on the tail and back. The American crocodile is sometimes confused with the Morelet's crocodile , a smaller species that is native to Mexico. New hatchlings are about 27 cm ( 10 + 1 ⁄ 2  in) in length and about 60 g (2 oz) in mass. The average adult in

2040-548: A specimen of 3 m (9.8 ft) weighed 7 kg (15 lb), and a specimen of 3.05 m (10.0 ft) weighed 18.5 kg (41 lb). In general, individuals over 5 m (16 ft) are rare. The record for maximum length of a Burmese python is 5.79 m (19 ft 0 in) and was caught 10 July 2023 in South Florida's Big Cypress National Preserve. Widely published data of specimens reported to have been several feet longer are not verified. At her death,

2142-474: A specimen weighed 29 kg (64 lb), a specimen of just over 4 m (13 ft) weighed 36 kg (79 lb), a specimen of 4.5 m (15 ft) weighed 40 kg (88 lb), and a specimen of 5 m (16 ft) weighed 75 kg (165 lb). In comparison, length-weight comparisons for males found: a specimen of 2.8 m (9 ft 2 in) weighed 12 kg (26 lb), 2.97 m (9 ft 9 in) weighed 14.5 kg (32 lb),

SECTION 20

#1732844887725

2244-414: A telemetry signal transmitted by one of several radio collars they had placed on a small number of woodrats. The signal led them to a python weighing 12 pounds (5.4 kg) and measuring approximately 7 ft (2 m) in length; the radio signal was coming from inside the python. A post-mortem examination revealed that the snake had very recently captured and eaten, not only the collared woodrat, but also

2346-531: A type of cover that is critical for protection against predators and heavy rainfall. According to local volunteer and photographer Clay DeGayner, the woodrats' population has declined significantly over the past twenty years and at one point had dropped to numbers as low as 25 to 50 woodrats. A captive breeding program was started to augment the endangered woodrat population and help it recover more quickly. The Key Largo Woodrat forages for food mostly at night and in tree tops. Though fallen fruit can easily found on

2448-449: A type of mouse due to its similar behavior and physical characteristics. One of the favored habitats of the woodrat comes under the protection of the hardwood hammocks . These trees provide a critical home for this endangered animal; however, the woodrats are finding it harder to live because of the decreasing size of their hammock habitat, and because of subsidized predation by free-roaming house cats. Local researchers have discovered that

2550-520: A variety of small mammals including foxes, rabbits, and raccoons. Due to their high predation levels, they have been implicated in the decline and even disappearance of many mammal species. In their invasive range, pythons also eat birds and occasionally other reptiles. Exceptionally large pythons may even require larger food items such as pigs or goats, and are known to have attacked and eaten alligators and adult deer in Florida. The digestive response of Burmese pythons to such large prey has made them

2652-455: Is a highly fecund species. Average clutch size is 38 eggs, and fecundity is over 20% after 15 years old. The species has a high adult survival rate and a long life span. Like all true crocodilians, the American crocodile is a quadruped , with short, stocky legs; a long, powerful tail; and a scaly hide with rows of ossified scutes running down its back and tail. Individuals can be identified by using multiple dorsal scute patterns. Its snout

2754-540: Is a result of the energetic cost of restarting many aspects of the digestive system, from rebuilding the stomach and small intestine to producing hydrochloric acid to be secreted in the stomach. Hydrochloric acid production is a significant component of the energetic cost of digestion, as digesting whole prey items requires the animal to be broken down without the use of teeth, either for chewing or tearing into smaller pieces. To compensate, once food has been ingested, Burmese pythons begin producing large amounts of acid to make

2856-520: Is able to reproduce asexually when in captivity. Offspring are clones of their mother and reproduction appears to be by a parthenogenetic mechanism that involves a modification of the meiotic process . Like all snakes, the Burmese python is carnivorous . Its diet consists primarily of birds and mammals, but also includes amphibians and reptiles. It is a sit-and-wait predator, meaning it spends most of its time staying relatively still, waiting for prey to approach, then striking rapidly. The snake grabs

2958-429: Is an excellent swimmer and needs a permanent source of water. It lives in grasslands , marshes, swamps, rocky foothills, woodlands, river valleys, and jungles with open clearings. It is a good climber and has a prehensile tail. It can stay in water for 30 minutes but mostly stays on land. Python invasion has been particularly extensive, notably across South Florida , where a large number of pythons can now be found in

3060-485: Is elongated and includes a strong pair of jaws . A 3.2-metre (10 ft 6 in), 164-kilogram (362 lb) specimen had a bite force of 4,355  N (979  lb f ). Its eyes have nictitating membranes for protection, along with lacrimal 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

3162-562: Is especially popular and is the most widely available morph. This morph is white with patterns in butterscotch yellow and burnt orange. Also, "labyrinth" specimens with maze-like patterns, khaki-colored "green", and "granite" with many small angular spots are available. Breeders have recently begun working with an island lineage of Burmese pythons. Early reports indicate that these dwarf Burmese pythons have slightly different coloring and pattern from their mainland relatives and do not grow much over 2.1 m (6 ft 11 in) in length. One of

Crocodile Lake National Wildlife Refuge - Misplaced Pages Continue

3264-541: Is listed on CITES Appendix II . It has been listed as vulnerable on the IUCN Red List since 2012, as the wild population is estimated to have declined by at least 30% in the first decade of the 21st century due to habitat loss and over-harvesting. To maintain Burmese python populations, the IUCN recommends increased conservation legislation and enforcement at the national and international levels to reduce harvesting across

3366-566: Is longer and narrower than that of the American alligator , but broader on average than that of the Orinoco crocodile . American crocodiles are also paler and more grayish than the relatively dark-hued American alligator. This crocodile species normally crawls on its belly, but it can also "high walk". Larger specimens can charge up to nearly 16 km/h (10 mph). They can swim as fast as 32 km/h (20 mph) by moving their bodies and tails in

3468-487: Is offered, and often act hungry even when they have recently eaten. As a result, they are often overfed, causing obesity -related problems to be common in captive Burmese pythons. Like the much smaller ball python , Burmese pythons are known to be easygoing or timid creatures, which means that if cared for properly, they can easily adjust to living near humans. Although pythons are typically afraid of people due to their great stature, and generally avoid them, special care

3570-489: Is one of the largest species of snakes . It is native to a large area of Southeast Asia and is listed as Vulnerable on the IUCN Red List . Until 2009, it was considered a subspecies of the Indian python , but is now recognized as a distinct species . It is an invasive species in Florida as a result of the pet trade . The Burmese python is a dark-colored non-venomous snake with many brown blotches bordered by black down

3672-457: Is one of the largest crocodile species. Males can reach lengths of more than 6.1 m (20 ft 0 in), weighing over 1,000 kilograms (2,200 lb). On average, mature males are more in the range of 2.9 to 4.1 m (9 ft 6 in to 13 ft 5 in) in length weighing up to about 400 kg (880 lb). As with other crocodile species, females are smaller, rarely exceeding 3.8 m (12 ft 6 in) in length even in

3774-402: Is one of the largest families of mammals, with 681 species in 130 genera and 6 subfamilies. The subfamilies of Cricetidae include: Arvicolinae (lemmings, voles, and muskrat), Cricetinae (hamsters), Lophiomyinae (crested rat), Neotominae (North American rats and mice), Sigmodontinae (New World rats and mice), and Tylomyinae (vesper rats and climbing rats) (Musser and Carleton, 2005). In other words,

3876-864: Is potential prey. The snout of the American crocodile is broader than some specialized fish-eating crocodilians (e.g., gharials and freshwater crocodiles ), allowing it to supplement its diet with a wider variety of prey. In addition the snout gets even broader and bulkier as the animal matures, a sign for a shift in prey items. Prey species have ranged in size from the insects taken by young American crocodiles to full-grown cattle taken by large adults, and can include various birds , mammals , turtles , snakes , lizards , smaller crocodilians , echinoderms , insects, arachnids , crabs , other crustaceans , snails , other molluscs , frogs , fish , and occasionally carrion and fruits . In Haiti , hatchling and juvenile American crocodiles lived primarily off of fiddler crabs ( Uca ssp.), making up 33.8% and 62.3% of

3978-454: Is still required when handling them. Given their adult strength, multiple handlers (up to one person per meter of snake) are usually recommended. Some jurisdictions require owners to hold special licenses, and as with any wild animal being kept in captivity, treating them with the respect an animal of this size commands is important. The Burmese python is frequently captive-bred for color, pattern, and more recently, size. Its amelanistic form

4080-526: Is the most widespread of the four extant species of crocodiles from the Americas. They are saltwater-tolerant, and have thus been capable of colonizing a multitude of islands within the Caribbean, and on some coastal Pacific islands as well. They inhabit waters such as mangrove swamps, river mouths, fresh waters, and salt lakes, and can even be found at sea, hence their wide distribution throughout southern Florida,

4182-590: The Florida Keys . A sizable population occurs near Homestead , at the Turkey Point Nuclear Generating Station . Some individuals have been sighted in Palm Beach , Brevard , Pinellas and Sarasota counties. Their range in Florida is the only place in the world where alligators and crocodiles coexist . The current US population, estimated at 2,000 and growing, is a sign of return to

Crocodile Lake National Wildlife Refuge - Misplaced Pages Continue

4284-963: The Florida Panhandle . The importation of Burmese pythons was banned in the United States in January 2012 by the U.S. Department of the Interior . A 2012 report stated, "in areas where the snakes are well established, foxes, and rabbits have disappeared. Sightings of raccoons are down by 99.3%, opossums by 98.9%, and white-tailed deer by 94.1%." Road surveys between 2003 and 2011 indicated an 87.3% decrease in bobcat populations, and in some areas rabbits have not been detected at all. Experimental efforts to reintroduce rabbit populations to areas where rabbits have been eliminated have mostly failed "due to high (77% of mortalities) rates of predation by pythons." Bird and coyote populations may be threatened, as well as

4386-547: The Oligocene / Miocene boundary. American crocodile populations in Florida, Jamaica and Hispaniola (in the Dominican Republic) differ in gene frequencies. Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological , molecular ( DNA sequencing ), and stratigraphic ( fossil age) data, as revised by the 2021 Hekkala et al. paleogenomics study using DNA extracted from

4488-527: The American crocodile was poorly understood. However, the discovery of the Miocene species Crocodylus checchiai indicates that it, the Orinoco crocodile ( Crocodylus intermedius ), Morelet's crocodile ( C. moreletii ), and the Cuban crocodile ( C. rhombifer ) all share an ancestor hailing from Africa. The newly discovered animal may also represent the base of the evolutionary radiation of these animals, representing

4590-406: The Burmese pythons in Florida have been found to prefer elevated habitats, since this provides the optimal conditions for nesting. In addition to elevated habitats, edge habitats are common places where Burmese pythons are found for thermoregulation, nesting, and hunting purposes. One of the Burmese python eradication movements with the biggest influence was the 2013 Florida Python Challenge . This

4692-491: The Caribbean islands of Cuba, Jamaica, Hispaniola, and the coasts of Mexico to as far south as Peru , Ecuador , Colombia , and Venezuela . The habitat of the American crocodile consists largely of coastal areas. It is also found in river systems , but tends to prefer salinity , resulting in the species congregating in brackish lakes , mangrove swamps, lagoons , cays , and small islands. Other crocodiles also have tolerance to saltwater due to salt glands underneath

4794-498: The Cold War, a missile facility was built on the grounds where the refuge now lies. The base, constructed in an area which habituated the hammock, built numerous buildings and launch-pads to aid in war efforts. By the year 2000, the refuge had started plans for a project to remove unnecessary buildings and asphalt pavement from areas that had once been hardwood hammock. The refuge hopes this task will restore more than 10 acres (4 ha) to

4896-577: The County Road 905 right-of-way for approximately 10 miles (16 km). On April 13, 2007, two researchers were studying North Key Largo's population of Key Largo woodrats, one of two federally endangered mammals found only in North Key Largo (the other being the Key Largo cotton mouse). Graduate student / biologist Joanne Potts and her assistant, Wildlife Refuge volunteer Clay DeGayner, were working in KLH and tracking

4998-409: The Everglades. More than 1,330 have been captured in the Everglades. A genetic study in 2017 revealed that the python population is composed of hybrids between the Burmese python and Indian python. The species also displays cytonuclear discordance which has made phylogenetic studies of its origin more complicated. By 2007, the Burmese python was found in northern Florida and in the coastal areas of

5100-591: The Florida Everglades . Between 1996 and 2006, the Burmese python gained popularity in the pet trade, with more than 90,000 snakes imported into the U.S. The current number of Burmese pythons in the Florida Everglades may have reached a minimum viable population and become an invasive species . Hurricane Andrew in 1992 was deemed responsible for the destruction of a python-breeding facility and zoo, and these escaped snakes spread and populated areas into

5202-669: The Greater Antilles (excluding Puerto Rico and Isla de la Juventud , where they are replaced by the introduced spectacled caiman ), Martinique , southern Mexico (including the Yucatán Peninsula ), Central America , and the South American countries of Colombia , Peru , Venezuela (including on Margarita Island ), and Ecuador . The American crocodile is especially plentiful in Costa Rica. American crocodiles coexist with

SECTION 50

#1732844887725

5304-412: The Key Largo woodrat and the Key Largo cotton mouse. Recent remote camera work has identified cats throughout the refuge and KLH, with some perched on top of nest structures. Cats have been returned that are 8 miles from their owner's homes. Cats are captured by staff and volunteers and turned over to the local animal shelter. The owners of cats that continually trespass may be subject to fines. During

5406-545: The Key Largo woodrat, and its smaller cousin the Key Largo cotton mouse ( Peromyscus gossypinus allapaticola ) are in subfamily Neotominae, along with most native North American rats and mice, and are only distantly related to the "true rats," including members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus , and the brown rat, Rattus norvegicus . Many members of other rodent genera and families are also referred to as rats, and share many characteristics with true rats.is considered more as

5508-511: The State Museum of Pennsylvania, stated that pythons are very good swimmers and, therefore, it seemed reasonable to assume it had swum from the Everglades into the Key Largo area refuge. From 2008 to 2013, a USGS study focused on detection and removal of pythons on the refuge yielded very few snakes. Feral and free-ranging cats have been identified as a major factor in the significant decline of

5610-474: The Stock Island Tree Snail and Eastern Indigo Snake are listed as threatened. All six species retain a precarious foothold in North Key Largo. Due to the once almost unrestricted commercial and residential development of the Florida Keys, the size and number of fragmented tropical hardwood hammock habitat have been reduced. Along with the decline of their habitat, the populations of animals who reside in

5712-582: The US population due to this hunting and, also, due to loss of habitat in the area. Due to its recovery trend, on March 20, 2007, the federal government downlisted the American crocodile from endangered to threatened , though the capturing and hunting of the crocodile is still forbidden. The crocodile is just one of several species of flora and fauna that occur in the refuge's habitats. The Key Largo Woodrat , Key Largo Cotton Mouse , Schaus Swallowtail butterfly , Florida semaphore cactus are listed as endangered, and

5814-462: The accidental translocation of the animal outside of its normal range. The species is thus not considered indigenous to Trinidad. The American crocodile's saline tolerance may have allowed it to inhabit limited portions of the United States, particularly 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

5916-606: The already-rare Florida panther . In addition to this correlational relationship, the pythons have also been experimentally shown to decrease marsh rabbit populations, further suggesting they are responsible for many of the recorded mammal declines. They may also outcompete native predators for food. For example, Burmese pythons also compete with the native American alligator , and numerous instances of alligators and pythons attacking—and in some cases, preying on—each other have been reported and recorded. By 2011, researchers identified up to 25 species of birds from nine avian orders in

6018-444: The area. One of the primary natural values of hammocks is that they "provide critical habitats for five federally endangered species." These species, mentioned in the first section of the article, have decreased in population due to the removal of hammock over the past few decades. The refuge, therefore, has attempted to restore hammock habitat wherever it can. Hardwood hammocks consist of mostly West Indian hardwood species that occur (in

6120-438: The back. In the wild, Burmese pythons typically grow to 5 m (16 ft), while specimens of more than 7 m (23 ft) are unconfirmed. This species is sexually dimorphic in size; females average only slightly longer, but are considerably heavier and bulkier than the males. For example, length-weight comparisons in captive Burmese pythons for individual females have shown: at 3.47 m (11 ft 5 in) length,

6222-517: The climate, as crocodiles are less tolerant of cold. Within the United States, the American crocodile's distribution is generally limited to the southern tip of Florida, though at least two have been found as far north as the Tampa Bay area . They are primarily found south of the latitude of Miami , in Everglades National Park , Florida Bay , Biscayne Bay , Dry Tortugas National Park and

SECTION 60

#1732844887725

6324-583: The commercial market. The widespread hunting did not cease until the 1970s: at one point in that decade, there were fewer than thirty total nests counted. As of 2020, further population seems to be expanding south to reclaim former habitat in the Florida Keys , where numbers are multiplying quickly, and old records indicate they once inhabited mangroves as far north as Tampa Bay. American crocodiles are more susceptible to cold weather than American alligators. American crocodiles do not have social groups, but occasionally they congregate for feeding and basking in

6426-449: The construction of the highway will most likely be used to help fill in the hole on the refuge. The main purpose of re-filling the hole is to populate the hardwood hammock by planting native vegetation in the area. The material referred to as 'muck' contains organic substances which will enhance the vegetation growth. Scientists in the area have claimed the substance to contain no damaging chemicals that would possibly harm animals or rather,

6528-422: The continental rivers can range from 2.9 to 4 m (9 ft 6 in to 13 ft 1 in) long and weigh up to 382 kg (842 lb) in males, while females can range from 2.5 to 3 m (8 ft 2 in to 9 ft 10 in) and weigh up to 173 kg (381 lb), the lower total length representing their average size at sexual maturity, the upper representing the expected upper size limit for

6630-421: The daytime. While basking, they will leave their mouths wide open that exposes blood vessels in the mouth to cooler and warmer air, which helps regulate body temperature. While an American alligator can survive in water temperatures of 7.2 °C (45.0 °F) and below for some time, an American crocodile in that environment would lose consciousness and drown due to hypothermia. American crocodiles, however, have

6732-418: The desired habitat for these creatures also has something to do with a type of roof coverage. They tend to prefer nesting in areas underneath rock formations, hurricane-downed trees, and even overturned boats. Experts say a devastating hurricane would down thousands of trees yet, would increase the woodrat population. The main shelter characteristic of the woodrats are areas containing roofs. The roof provides

6834-456: The diet by weight, respectively. Elsewhere, aquatic insects and their larvae and snails are near the top of the food list for American crocodiles at this very early age. Immature and subadult American crocodiles, per a study in Mexico , have a more diverse diet that can include insects, fish, frogs, small turtles, birds and small mammals. One specimen of 1.2 m (3 ft 11 in) had a catfish,

6936-480: The digestive tract remains of 85 Burmese pythons found in Everglades National Park. Native bird populations are suffering a negative impact from the introduction of the Burmese python in Florida; among these bird species, the wood stork is of specific concern, now listed as federally endangered. Numerous efforts have been made to eliminate the Burmese python population in the last decade. Understanding

7038-610: The early spring, with females laying clutches of 12–36 eggs in March or April. They remain with the eggs until they hatch, wrapping around them and twitching their muscles in such a way as to raise the ambient temperature around the eggs by several degrees. Once the hatchlings use their egg tooth to cut their way out of their eggs, no further maternal care is given. The newly hatched babies often remain inside their eggs until they are ready to complete their first shedding of skin, after which they hunt for their first meal. The Burmese python

7140-421: The ecosystem. Originally, US Highway 1 had evacuated the muck in order to improve road conditions near the refuge. "I feel very good about possibly being able to solve our problem and the [Department of Transportation] problem," Klett said in an interview. The Department of Transportation was required to move the muck in an effort to clean up the area; however, staff at the refuge decided to ask for permission to use

7242-475: The end of the 19th century, hunting them for their leather became a cottage industry in South Florida, and beginning in 1910, habitat destruction commenced on a massive scale, with the construction of a railroad designed to connect the mainland with the Keys. Crocodile hunters, who migrated to the upper Florida Keys before and after the railroad’s construction, slaughtered almost every crocodile in northeast Florida Bay for

7344-944: The extinct Voay . Voay † Crocodylus anthropophagus † Crocodylus thorbjarnarsoni † Crocodylus palaeindicus † Crocodylus Tirari Desert † Crocodylus johnstoni Freshwater crocodile [REDACTED] Crocodylus novaeguineae New Guinea crocodile Crocodylus mindorensis Philippine crocodile Crocodylus porosus Saltwater crocodile [REDACTED] Crocodylus siamensis Siamese crocodile [REDACTED] Crocodylus palustris Mugger crocodile [REDACTED] Crocodylus checchiai † Crocodylus falconensis † Crocodylus suchus West African crocodile Crocodylus niloticus Nile crocodile [REDACTED] Crocodylus moreletii Morelet's crocodile Crocodylus rhombifer Cuban crocodile [REDACTED] Crocodylus intermedius Orinoco crocodile Crocodylus acutus American crocodile [REDACTED] The American crocodile

7446-564: The forest floor, that is also where the rat is most vulnerable to its predators. During the day, Key Largo woodrats shelter in crevices and fissures in the island's limestone substrate, and under dense tangles of tree roots. The normal diet of the woodrats consists of green leaves, flowers, buds and fruit from the trees they reside in and under. Woodrats are seldom found near human habitation and, unlike introduced rat species that came to America from Europe and Asia, woodrats are not attracted to or known to consume garbage. Though it had ended by 2010,

7548-407: The ground and in trees, but as they gain girth, they tend to restrict most of their movements to the ground. They are also excellent swimmers, being able to stay submerged for up to half an hour. Burmese pythons spend the majority of their time hidden in the underbrush. In the northern parts of its range, the Burmese python may brumate for some months during the cold season in a hollow tree, a hole in

7650-532: The habitat have also declined. Though the refuge office distributes brochures and information, and has a 2,500 square-foot butterfly garden beside the office, the refuge's natural areas are closed to the public. This closure is necessary to protect the threatened and endangered listed species that occur on the Refuge. The woodrat is a member of the Order Rodentia, and Family Cricetidae, subfamily Neotominae. Critecidae

7752-405: The head of Biscayne Bay , Hornaday and his companions searched for it and reported: In a few hours, we got sight of him, out on the bank in a saw-grass wallow. He was a monster for size—a perfect whale of a saurian, gray in color—and by all the powers, he was a genuine crocodile! Crocodylus floridanus is now considered an invalid junior synonym of C. acutus . Until 2020, the evolution of

7854-725: The largest living crocodilians in the Neotropical realm . It is estimated that specimens of C.acutus measuring 3 m (9 ft 10 in) in TL would weigh around 100 kg (220 lb), specimens measuring 4 m (13 ft 1 in) in TL would weigh around 270 kg (600 lb), and specimens measuring 6.25 m (20 ft 6 in) in TL would weigh around 1,100 kg (2,400 lb). However, body mass can be fairly variable in mature adults. A large male specimen from Costa Rica measuring 4.83 m (15 ft 10 in) in total length weighed about 538 kg (1,186 lb). On

7956-480: The largest-bodied population. Like any other large crocodilian, the American crocodile is potentially dangerous to humans, but it tends not to be as aggressive as some other species. American crocodiles coexist with the American alligator in Florida, and with the smaller spectacled caiman within Central America and South America. The IUCN lists the American crocodile as vulnerable . The American crocodile

8058-502: The main purpose of the breeding program was to enhance the wild population in order to mitigate the population decline. Divided into a couple of different stages, the first step was to trap woodrats and then to breed them in a controlled, captive environment. Offspring were then released into the refuge, but unfortunately fell victim to predators, primarily feral cats. Crocodile Lake National Wildlife Refuge (CLWR) and Dagny Johnson Key Largo Hammock Botanical State Park (KLH) are separated by

8160-476: The mainland United States) only in southernmost Florida, though some also remain on Puerto Rico and the US Virgin Islands. Most of South Florida's hardwood hammock habitat was lost to urban and suburban development. There is a 2.16 acres (8,700 m) hole (officially known as the "Keystone Pit") in the refuge, which manager Steven Klett has wanted to fill in order to revitalize the hammock habitat. The pit

8262-443: The mammals and birds of south Florida and the Florida Keys have never been exposed to a predatory snake of this size, and may have a hard time adapting defensive strategies before their populations are wiped out. A study of python prey, in Everglades National Park shows an alarming declines among small mammal populations in the park. “There's a good chance we never would have found him,” said Scott Hardin, exotic-species coordinator for

8364-457: The missing link between crocodiles in Africa and the Americas. The genus Crocodylus likely originated in Africa and radiated outward toward Southeast Asia and the Americas, although an Australia/Asia origin has also been considered. Phylogenetic evidence supports Crocodylus diverging from its closest recent relative, the extinct Voay of Madagascar , around 25 million years ago, near

8466-483: The muck (layering 36 inches) for gaping the hole. [REDACTED] Media related to Crocodile Lake National Wildlife Refuge at Wikimedia Commons American crocodile The American crocodile ( Crocodylus acutus ) is a species of crocodilian found in the Neotropics . It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida ,

8568-421: The northernmost portion of their range. There were suspicions as early as 1829 by Rafinesque that there were more than just alligators in the state, but confirmation could not be acquired until 1869, when a specimen could be brought back for examination. Records show they were plentiful in areas like Key Largo , Miami Beach , and wherever there were the appropriate mangroves for nesting and foraging. However, at

8670-1103: The other hand, another specimen measuring 3.95 m (13 ft 0 in) in total length was found to have weighed 500 kg (1,100 lb) An individual named "Papillon" was considered to be one of the largest American crocodiles in captivity. It measured 4.3 m (14 ft 1 in) in length, weighed 500 kg (1,100 lb), and was estimated to be more than 80 years old when he died. The largest recorded female measured 4.4 m (14 ft 5 in) in length and weighed 450 kg (1,000 lb). Exceptionally large specimens may arguably exceed 5 m (16 ft 5 in), possibly reaching or exceeding 6.1 m (20 ft 0 in), but such specimens are unverified and possibly dubious although some are arguably supported by size projections from skull lengths. These exceptionally large crocodiles are estimated to range between 6 and 7 m (19 ft 8 in and 23 ft 0 in) in length and weigh between 900 and 1,300 kg (2,000 and 2,900 lb), though these are mere estimations and not verified. The American crocodile

8772-437: The preferred habitat of the species is needed to narrow down the python hunt. Burmese pythons have been found to select broad-leafed and low-flooded habitats. Broad-leafed habitats comprise cypress, overstory, and coniferous forest. Though aquatic marsh environments would be a great source for prey, the pythons seem to prioritize environments allowing for morphological and behavioral camouflage to be protected from predators. Also,

8874-535: The pythons as hosts even though they are recently introduced. Invasive Burmese pythons also face certain physiological changes. Unlike their native South Asian counterparts who spend long periods fasting due to seasonal variation in prey availability, pythons in Florida feed year-round due to the constant availability of food. They are also vulnerable to cold stress, with winter freezes resulting in mortality rates of up to 90%. Genomic data suggests natural selection on these populations favors increased thermal tolerance as

8976-848: The respective sex in most known populations. Common weights of adult American crocodiles in Florida may range from 50 to 250 kg (110 to 550 lb) with corresponding lengths of 2.5 to 3.85 m (8 ft 2 in to 12 ft 8 in). With extensive conservation efforts underway, there appears to be an increase in the number of large American crocodiles in Florida, some of the largest reportedly exceeding 4 m (13 ft 1 in) in length. Eight adult American crocodiles from Costa Rica ranged in total length from 2.82 to 4.83 m (9 ft 3 in to 15 ft 10 in). Large adults of this species are capable of reaching 500–600 kg (1,100–1,300 lb) in weight, with individuals approaching 6 m (19 ft 8 in) exceeding 1,000 kg (2,200 lb) in weight, ranking it among

9078-446: The riverbank, or under rocks. Brumation is biologically distinct from hibernation. While the behavior has similar benefits, allowing organisms to endure the winter without moving, it also involves the preparation of both male and female reproductive organs for the upcoming breeding season. The Florida population also goes through brumation. They tend to be solitary and are usually found in pairs only when mating. Burmese pythons breed in

9180-548: The smaller spectacled caiman within Central America. The only other crocodiles present within the American crocodile's range are the Morelet's crocodile , and the critically endangered Cuban and Orinoco crocodiles . In addition, an American/Cuban crocodile hybrid was recently discovered in the Cancún area of Mexico. The crocodile likely originated in the Zapata Swamp of Cuba (the only place where these wild hybrids exist, and where

9282-635: The snake's native range. The IUCN also recommends increased research into its population ecology and threats. In Hong Kong, it is a protected species under Wild Animals Protection Ordinance Cap 170. It is also protected in Thailand, Vietnam, China, and Indonesia. However, it is still common only in Hong Kong and Thailand, with rare to very rare statuses in the rest of its range. Burmese pythons are often sold as pets, and are made popular by their attractive coloration and apparently easy-going nature. However, they have

9384-434: The state Fish and Wildlife Conservation Commission. “This was always my concern, what would happen when an exotic species like the python intersects with an endangered species. Here it's happened, and it has the potential to be a serious problem.” Hardin later assumed the 7.5 feet (2.3 m) snake was either an escaped or released pet by someone who realized the python "[had] become a burden". Walter Meshaka, senior curator for

9486-467: The stomach acidic enough to turn the food into a semi-liquid that can be passed through to the small intestine and undergo the rest of the digestive process. The energy cost is highest in the first few days after eating when these regenerative processes are most active, meaning Burmese pythons rely on existing food energy storage to digest a new meal. Overall, the entire digestive process from food intake to defecation lasts 8–14 days. The Burmese python

9588-512: The swamps available, as well as brackish portions of rivers. 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 large American crocodile population) and slowly repopulating Grand Cayman. There have been reports of American crocodiles in Trinidad , however, those sightings are thought to have arisen due to

9690-457: The time and rely on water gleaned from marine food 80% of the time. In Haiti, adults appeared to live largely off of various birds , including herons , storks , flamingos , pelicans , grebes , coots and moorhens , followed by concentrations of fish including Tilapia and Cichlasoma , at times being seen to capture turtles , dogs and goats . One 3 m (9 ft 10 in) adult from Honduras had stomach contents consisting of

9792-555: The tongue, but the American crocodile is the only species other than the saltwater crocodile to commonly live and thrive in saltwater. They can be found on beaches and small island formations without any freshwater source, such as many cays and islets across the Caribbean . They are also found in hypersaline lakes; one of the largest known populations inhabits Lago Enriquillo in the Dominican Republic . The American crocodile

9894-539: The two species are sympatric ), and swam to the Yucatán Peninsula . One of its largest documented populations (the largest in the Caribbean ) is in Lago Enriquillo, a hypersaline lake in the Dominican Republic. In Haiti , the only population known is in the brackish lake Etang Saumâtre , where the population is nearing extirpation due to overhunting and poaching. In Jamaica, the species inhabits most of

9996-569: The typical way for most crocodilians, ambushing terrestrial prey when it comes to edge of the water or is sitting in shallows and dragging it down to be drowned or attempting to ambush aquatic prey from near the surface of the water. Adult American crocodiles are apex predators; they have no natural predators. They are known predators of lemon sharks , and sharks avoid areas with American crocodiles. Usually, American alligators are dominant over and more behaviorally aggressive than American crocodiles. However, on one occasion, an American crocodile in

10098-404: Was a month-long contest wherein a total of 68 pythons were removed. The contest offered incentives such as prizes for longest and greatest number of captured pythons. The purpose of the challenge was to raise awareness about the invasive species, increase participation from the public and agency cooperation, and to remove as many pythons as possible from the Florida Everglades. The challenge has run

10200-474: Was described by Georges Cuvier in 1807, and became known as the "sharp-snout alligator". In 1822, Constantine Samuel Rafinesque postulated that the species was in fact a crocodile. The species was redescribed as Crocodylus floridanus by William Temple Hornaday in 1875, when Hornaday and C. E. Jackson were sent to Florida to collect alligator hides. Upon hearing of a "big old gator" in Arch Creek at

10302-497: Was dug 30 to 40 years ago in order to obtain fossilized coral to build and decorate fireplaces and other types of architecture (much of the limestone rock was mined as well). According to an article published by McClatchy-Tribune Business News, "ever-growing piles of muck from widening U.S. 1 north of Key Largo could be used to fill in a gaping hole in the Crocodile Lake National Wildlife Refuge". The muck from

10404-482: Was fish for sub-adults and adults with sub-adults having a broader prey base than either younger or adult American crocodiles. In Costa Rica, American crocodiles have been recorded hunting and killing adult female olive ridley sea turtles ( Lepidochelys olivacea ) when they come to nest around beaches. Reportedly, these American crocodiles hunt primarily in the first few hours after nightfall, especially on moonless nights, although they will feed at any time. It hunts in

#724275