American alligator

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American alligator
Temporal range: 8–0  Ma
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Miocene–Recent
American Alligator.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Family: Alligatoridae
Genus: Alligator
Species:
A. mississippiensis
Binomial name
Alligator mississippiensis
(Daudin, 1802)
Rangemapx.gif
Approximate range of American alligator
Synonyms [2]
  • Crocodilus mississipiensis [sic]
    Daudin, 1802
  • Crocodilus lucius
    Cuvier, 1807
  • Crocodilus cuvieri
    Leach, 1815
  • Alligator lucius
    A.M.C. Duméril & Bibron, 1836
  • Alligator mississippiensis [sic]
    Holbrook, 1842

The American alligator (Alligator mississippiensis), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile endemic to the Southeastern United States. It is one of two living species in the genus Alligator within the family Alligatoridae; it is larger than the other extant alligator species, the Chinese alligator.

Reptile class of animals

Reptiles are tetrapod animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of modern amphibians, is called herpetology.

Southeastern United States eastern portion of the Southern United States

The Southeastern United States is broadly, the eastern portion of the Southern United States, and the southern portion of the Eastern United States. It comprises at least a core of states on the lower Atlantic seaboard and eastern Gulf Coast. Expansively, it includes everything south of the Mason-Dixon line, the Ohio River and the 36°30' parallel, and as far west as Arkansas and Louisiana. There is no official U.S. government definition of the region, though various agencies and departments use different definitions.

A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

Contents

Adult male American alligators measure 11 to 15 ft (3.4 to 4.6 m) in length, and can weigh up to 999 lb (453 kg). Females are smaller, measuring 8.5 to 10 ft (2.6 to 3.0 m) in length. The American alligator inhabits freshwater wetlands, such as marshes and cypress swamps from Texas to southeastern and coastal Virginia. It is distinguished from the sympatric American crocodile by its broader snout, with overlapping jaws and darker coloration, and is less tolerant of saltwater but more tolerant of cooler climates than the American crocodile, which is found only in tropical climates.

Wetland A land area that is permanently or seasonally saturated with water

A wetland is a distinct ecosystem that is inundated by water, either permanently or seasonally, where oxygen-free processes prevail. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil. Wetlands play a number of functions, including water purification, water storage, processing of carbon and other nutrients, stabilization of shorelines, and support of plants and animals. Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. Whether any individual wetland performs these functions, and the degree to which it performs them, depends on characteristics of that wetland and the lands and waters near it. Methods for rapidly assessing these functions, wetland ecological health, and general wetland condition have been developed in many regions and have contributed to wetland conservation partly by raising public awareness of the functions and the ecosystem services some wetlands provide.

Marsh A wetland that is dominated by herbaceous rather than woody plant species

A marsh is a wetland that is dominated by herbaceous rather than woody plant species. Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs. This form of vegetation is what differentiates marshes from other types of wetland such as swamps, which are dominated by trees, and mires, which are wetlands that have accumulated deposits of acidic peat.

Swamp A forested wetland

A swamp is a wetland that is forested. Many swamps occur along large rivers where they are critically dependent upon natural water level fluctuations. Other swamps occur on the shores of large lakes. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundation or soil saturation. The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps. In the boreal regions of Canada, the word swamp is colloquially used for what is more correctly termed a bog, fen, or muskeg. The water of a swamp may be fresh water, brackish water or seawater. Some of the world's largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo.

American alligators are apex predators and consume fish, amphibians, reptiles, birds, and mammals. Hatchlings feed mostly on invertebrates. They play an important role as ecosystem engineers in wetland ecosystems through the creation of alligator holes, which provide both wet and dry habitats for other organisms. Throughout the year, in particular during the breeding season, American alligators bellow to declare territory and locate suitable mates. [3] Male American alligators use infrasound to attract females. Eggs are laid in a nest of vegetation, sticks, leaves, and mud in a sheltered spot in or near the water. Young are born with yellow bands around their bodies and are protected by their mother for up to one year. [4]

Apex predator Predator at the top of a food chain

An apex predator, also known as an alpha predator or top predator, is a predator at the top of a food chain, with no natural predators.

Fish vertebrate animal that lives in water and (typically) has gills

Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered paraphyletic by excluding the tetrapods. Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is used in the cladistic sense, including tetrapods. The traditional term pisces is considered a typological, but not a phylogenetic classification.

Amphibian A class of ectothermic tetrapods, which typically breed in water

Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia. Modern amphibians are all Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe.

The conservation status of the American alligator is listed as Least Concern by the International Union for Conservation of Nature. Historically, hunting had decimated their population, and the American alligator was listed as an endangered species by the Endangered Species Act of 1973. Subsequent conservation efforts have allowed their numbers to increase and the species was removed from endangered status in 1987. American alligators are now harvested for their skins and meat. The species is the official state reptile of three states: Florida, Louisiana, and Mississippi.

International Union for Conservation of Nature international organisation

The International Union for Conservation of Nature is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable".

Endangered species Species of organisms facing a very high risk of extinction

An endangered species is a species which has been categorized as very likely to become extinct in the near future. Endangered (EN), as categorized by the International Union for Conservation of Nature (IUCN) Red List, is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR).

Endangered Species Act of 1973 United States Law

The Endangered Species Act of 1973 serves as the enacting legislation to carry out the provisions outlined in The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Designed to protect critically imperiled species from extinction as a "consequence of economic growth and development untempered by adequate concern and conservation", the ESA was signed into law by President Richard Nixon on December 28, 1973. The law requires federal agencies to consult with the Fish and Wildlife Service &/or the NOAA Fisheries Service to ensure their actions are not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of designated critical habitat of such species. The U.S. Supreme Court found that "the plain intent of Congress in enacting" the ESA "was to halt and reverse the trend toward species extinction, whatever the cost." The Act is administered by two federal agencies, the United States Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS).

Taxonomy

The American alligator was first classified by French zoologist François Marie Daudin as Crocodilus mississipiensis in 1801. In 1807 Georges Cuvier created the genus Alligator; [5] the American alligator shares this genus with the Chinese alligator. They are grouped in the family Alligatoridae with the caimans. The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile or the gharial. [6]

François Marie Daudin was a French zoologist.

Georges Cuvier French naturalist, zoologist and paleontologist (1769–1832)

Jean Léopold Nicolas Frédéric, Baron Cuvier, known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils.

Chinese alligator species of reptile

The Chinese alligator, also known as the Yangtze alligator, China alligator, or historically the muddy dragon, is a critically endangered crocodilian endemic to China. It and the American alligator are the only living species in the genus Alligator of the family Alligatoridae. Dark gray or black in color with a fully armored body, the Chinese alligator grows to 1.5–2.1 metres (5–7 ft) in length and weighs 36–45 kilograms (80–100 lb) as an adult. It brumates in burrows in winter and is nocturnal in summer. Mating occurs in early summer, with females most commonly producing 20–30 eggs, which are smaller than those of any other crocodilian. The species is an opportunistic feeder, primarily eating fish and invertebrates. A vocal species, adults bellow during the mating season and young vocalize to communicate with their parents and other juveniles. Captive specimens have reached age 70, and wild specimens can live to over 50.

Phylogeny

Alligator prenasalis fossil Alligator prenasalis.JPG
Alligator prenasalis fossil

Members of this superfamily first arose in the late Cretaceous, about 100–66 million years ago. Leidyosuchus of Alberta is the earliest known fossil, from the Campanian era 83 to 72 million years ago. Fossil alligatoroids have been found throughout Eurasia, because bridges across both the North Atlantic and the Bering Strait connected North America to Eurasia about 66 to 23 million years ago.

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series. The Cretaceous is named after the white limestone known as chalk which occurs widely in northern France and is seen in the white cliffs of south-eastern England, and which dates from this time.

<i>Leidyosuchus</i> genus of reptiles

Leidyosuchus is an extinct genus of alligatoroid from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is L. canadensis. It is known from a number of specimens from the middle Campanian age Dinosaur Park Formation. It was a medium-sized alligatorid, with a maximum skull length greater than 40 centimeters (16 in).

Alberta Province of Canada

Alberta is a western province of Canada. With an estimated population of 4,067,175 as of 2016 census, it is Canada's fourth most populous province and the most populous of Canada's three prairie provinces. Its area is about 660,000 square kilometres (250,000 sq mi). Alberta and its neighbour Saskatchewan were districts of the Northwest Territories until they were established as provinces on September 1, 1905. The premier is Jason Kenney as of April 30, 2019.

Alligators and caimans split in North America during the late Cretaceous, and the caimans reached South America by the Paleogene, before the closure of the Isthmus of Panama during the Neogene period, from about 23 to 2.58 million years ago. The Chinese alligator likely descended from a lineage that crossed the Bering land bridge during the Neogene. Fossils identical to the existing American alligator are found throughout the Pleistocene, from 2.5 million to 11.7 thousand years ago. [7] In 2016, a Miocene (about 23 to 5.3 million years ago) fossil skull of an alligator was found at Marion County, Florida. Unlike the other extinct alligator species of in the same genus, the fossil skull was virtually indistinguishable from that of the modern American alligator. This alligator and the American alligator are now considered to be sister taxa, meaning that the Alligator mississippiensis lineage has existed in North America for over 8 million years. [8]

The alligator's full mitochondrial genome was sequenced in the 1990s and it suggests the animal evolved at a rate similar to mammals and greater than birds and most cold-blooded vertebrates. [9] However, the full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds. [10]

Characteristics

American alligator skull Alligator Crane et Mandibule.jpg
American alligator skull

Domestic American alligators range from long and slender to short and robust, possibly in response to variations in factors such as growth rate, diet, and climate.

Size

The American alligator is a relatively large species of crocodilian. On average it is the second largest species in the family Alligatoridae, behind only the black caiman. [11] Weight varies considerably depending on length, age, health, season and available food sources. Similar to many other reptiles that range expansively into temperate zones, American alligators from the northern end of their range, such as southern Arkansas, Alabama, and northern North Carolina, tend to reach smaller sizes. Large adult American alligators tend to be relatively robust and bulky compared to other similarly length crocodilians, for example captive males measuring 10 to 13 ft (3.0 to 4.0 m) were found to weigh 440 to 770 lb (200 to 350 kg) - although captive specimens may outweigh wild specimens due to lack of hunting behavior and other stressors. [12] [13]

Relation to age

As with all crocodilians, and as opposed to many mammals where size eventually diminishes with old age, healthy American alligators may continue to expand throughout their lives and the oldest specimens are the largest. Very old, large male American alligators reach an expected maximum size of up to 15 ft (4.6 m) in length, weighing up to 999 lb (453 kg), while females reach a maximum of 10 ft (3.0 m). [14] [15] On rare occasions, a large, old male may grow to an even greater length. [16] [17]

Largest

During the 19th and 20th centuries, larger males reaching 16.5 to 19.75 ft (5.03 to 6.02 m) have been reported. [18] The largest reported individual size was a male killed in 1890 on Marsh Island, Louisiana, and reportedly measured at 19 ft (5.8 m) in length, but no voucher specimen was available, since the American alligator was left on a muddy bank after having been measured due to having been too massive to relocate. [17] If the size of this animal was correct, it would have weighed approximately 2,200 lb (1,000 kg). [19] In Arkansas a man killed an American alligator that was 13 ft 3 in (4.04 m) and 1,380 lb (630 kg). [20] The largest American alligator ever killed in Florida was 17.5 ft (5.3 m), as reported by the Everglades National Park. [21] [22] The largest American alligator scientifically verified in Florida for the period from 1977 to 1993 was reportedly 14 ft (4.3 m) and weighed 1,042 lb (473 kg), although another specimen (size estimated from skull) may have measured 15 ft (4.6 m). [12]

Average

American alligators do not normally reach such extreme sizes. In mature males, most specimens grow up to about 11 ft (3.4 m) in length, and will weigh up to 795 lb (361 kg), [23] while in females, the mature size is normally around 8.5 ft (2.6 m), with a body weight of up to 200 lb (91 kg). [24] [25] In Newnans Lake, Florida, adult males averaged 161 lb (73 kg) in mass and measured 8.1 ft (2.5 m) in length while adult females averaged 121.5 lb (55.1 kg) and measured 7 ft 3 in (2.21 m). [26] In Lake Griffin State Park, Florida, adults weighed on average 128 lb (58 kg). [27] Weight at sexual maturity per one study was stated as averaging 66 lb (30 kg) while adult weight was claimed as 350 lb (160 kg). [28]

Sexual dimorphism

While noticeably sexual dimorphic in size in very mature specimens, the sexual dimorphism of this species is relatively modest amongst crocodilians. [29] In the saltwater crocodile, for example, the females are only slightly larger at average (7 ft 10.5 in (2.400 m) in the American alligator, 8.5 ft (2.6 m) in the saltwater crocodile) than female American alligators, but the mature males, at 14 to 17 ft (4.3 to 5.2 m) on average as opposed to 8 to 13 ft (2.4 to 4.0 m) expected in mature male American alligators, are considerably bigger than male American alligators and at median are nearly twice as long as and at least four times as heavy as the female saltwater crocodiles of the same species. [30] Given that female American alligators have relatively higher survival rates at an early age and a large percentage of given populations are comprised by immature or young breeding American alligators, relatively few large mature males of the expected mature length of 11 ft (3.4 m) or more are typically seen. [31]

Color

Dorsally, adult American alligators may be olive, brown, gray, or black in color, while their undersides are cream-colored. [32] Some American alligators are missing an inhibited gene for melanin, which makes them albino. These American alligators are extremely rare and almost impossible to find in the wild. They could only survive in captivity, as they are very vulnerable to the sun and predators. [33]

Jaws, teeth, and snout

American alligator showing teeth AmericanAlligator3.jpg
American alligator showing teeth
The snout of an American alligator American alligator (Alligator mississippiensis) skull nostrils at the Royal Veterinary College anatomy museum.JPG
The snout of an American alligator

The teeth number 74–80. [18] As American alligators grow and develop, the morphology of their teeth and jaws change significantly. [34] Juveniles have small, needle-like teeth that become much more robust as well as narrow snouts that become more broad as the individuals develop. [34] These morphological changes correspond to shifts in the alligators' diets, from smaller prey items such as fish and insects to larger prey items such as turtles, birds, and other large vertebrates. [34] American alligators have broad snouts, especially in captive individuals. When the jaws are closed, the edges of the upper jaws cover the lower teeth which fit into the jaws' hollows. Like the spectacled caiman, this species has a bony nasal ridge, though it is less prominent. [18]

Bite

Adult American alligators held the record as having the strongest laboratory-measured bite of any living animal, measured at up to 2,960  lbf (1,340  kgf ; 13,200  N ). This experiment had not been, at the time of the paper published, replicated in any other crocodilians, and the same laboratory was able to measure a greater bite force of 3,690 lbf (1,670 kgf; 16,400 N) in saltwater crocodiles; [35] [36] notwithstanding this very high biting force, the muscles opening the American alligator's jaw are quite weak, and the jaws can be held closed by hand or tape when an American alligator is captured. There is no significant difference between the bite forces of male and female American alligators of equal size. [34]

Movement

X-ray video of a female American alligator showing contraction of the lungs while breathing

When on land, an American alligator moves either by sprawling or walking, the latter involving the reptile lifting its belly off the ground. The sprawling of American alligators and other crocodylians is not similar to that of salamanders and lizards, being similar to walking. Therefore, the two forms of land locomotion can be termed the "low walk" and the "high walk". Unlike most other land vertebrates, American alligators increase their speed through the distal rather than proximal ends of their limbs. [37] In the water, American alligators swim like fish, moving their pelvic regions and tails from side to side. [38] During respiration, air flow is unidirectional, looping through the lungs during inhalation and exhalation; [39] the American alligator's abdominal muscles can alter the position of the lungs within the torso, thus shifting the center of buoyancy, which allows the American alligator to dive, rise, and roll within the water. [40]

Distribution

American alligator (right) and American crocodile (left) at Mrazek Pond, Florida Crocodile and Gator at Mrazek Pond (2), EVER, NPSPhoto, SCotrell, 4-2011 (9255694189).jpg
American alligator (right) and American crocodile (left) at Mrazek Pond, Florida

American alligators are found in the wild in the southeastern United States, from the Great Dismal Swamp in Virginia and North Carolina, south to Everglades National Park in Florida, and west to the southern tip of Texas as well as the northern border region of the Mexican state of Tamaulipas. [41] They are found in parts of Virginia, North Carolina, South Carolina, Georgia, Florida, Louisiana, Alabama, Mississippi, Arkansas, Oklahoma, and Texas. In 2018 there were several confirmed sightings of animals that had moved north into West Tennessee. [42] Some of these locations appear to be relatively recent introductions, with often small but reproductive populations. [43]

Habitat

They inhabit swamps, streams, rivers, ponds, and lakes. A lone American alligator was spotted for over ten years living in a river north of Atlanta, Georgia. [44] Females and juveniles are also found in Carolina Bays and other seasonal wetlands. While they prefer fresh water, American alligators may sometimes wander into brackish water, [45] but are less tolerant of salt water than crocodiles, as the salt glands on their tongues do not function. [46] One study of alligators in north-central Florida found the males preferred open lake water during the spring, while females used both swampy and open water areas. During summer, males still preferred open water, while females remained in the swamps to construct their nests and lay their eggs. Both sexes may den underneath banks or clumps of trees during the winter. [26]

Cold tolerance

American alligators are less vulnerable to cold than American crocodiles. Unlike an American crocodile, which would immediately succumb to the cold and drown in water at 45 °F (7 °C) or less, an American alligator can survive in such temperatures for some time without displaying any signs of discomfort. [47] This adaptiveness is thought to be the reason why American alligators are widespread further north than the American crocodile. [47] In fact, the American alligator is found farther from the equator and is more equipped to handle cooler conditions than any other crocodilian. [48] When the water begins to freeze, American alligators go into a period of brumation; they stick their snouts through the surface which allows them to breathe above the ice. [45]

Ecology and behavior

A young American alligator preying on a bullfrog Gator with bullfrog at Lake Woodruff - Flickr - Andrea Westmoreland.jpg
A young American alligator preying on a bullfrog

Basking

American alligators primarily bask on shore, but also can and will climb into and perch on tree limbs to bask if no shoreline is available. This is not often seen, since if disturbed they will quickly retreat back into the water by jumping from their perch. [49]

Holes

American alligators modify wetland habitats, most dramatically in flat areas such as the Everglades, by constructing small ponds known as alligator holes. This behavior has qualified the American alligator to be considered a keystone species. Alligator holes retain water during the dry season and provide a refuge for aquatic organisms. Aquatic organisms that survive the dry season by seeking refuge in alligator holes are a source of future populations. The construction of nests along the periphery of alligator holes, as well as a buildup of soils during the excavation process, provide drier areas for other reptiles to nest and a place for plants that are intolerant of inundation to colonize. Alligator holes are an oasis during the Everglades dry season, so are consequently important foraging sites for other organisms. [50] In the limestone depressions of cypress swamps, alligator holes tend to be large and deep, while those in marl prairies and rocky glades are usually small and shallow, and those in peat depressions of ridge and slough wetlands are more variable. [51]

American alligator in the Everglades

Prey

Bite and mastication

The teeth of the American alligator are designed to grip prey, but can not rip or chew flesh like teeth of some other predators (such as canids and felids), and depend on their gizzard instead to masticate their food. The American alligator is capable of biting though a turtle's shell or a moderately sized mammal bone. [52]

Tool use

American alligators have been documented using lures to hunt prey such as birds. [53] This means they are among the first reptiles recorded to use tools. By balancing sticks and branches on their heads, American alligators are able to lure birds looking for suitable nesting material to kill and consume. This strategy, which is shared by the mugger crocodile, is particularly effective during the nesting season, in which birds are more likely to gather appropriate nesting materials. [54]

Aquatic vs terrestrial

American alligator about to eat a crab. American Alligator eating Blue Crab 2.JPG
American alligator about to eat a crab.

Fish and other aquatic prey taken in the water or at the water's edge form the major part of American alligator's diet and may be eaten at any time of the day or night. Adult American alligators also spend considerable time hunting on land, up to 170 ft (50 m) from water, ambushing terrestrial animals on trailsides and road shoulders. Usually, terrestrial hunting occurs on nights with warm temperatures. [55] When hunting terrestrial prey, American alligators may also ambush them from the edge of the water by grabbing them and pulling the prey into the water, the preferred method of predation of larger crocodiles. [16]

Additionally, American alligators have recently been filmed and documented killing and eating sharks and rays; four incidents documented indicated that bonnetheads, lemon sharks, Atlantic stingrays and nurse sharks are components of the animal's diet. Sharks are also known to prey on American alligators in turn, indicating encounters between the two predators are more common than thought. [56] [57]

Common

The American alligator is considered an apex predator throughout its range. They are opportunists and their diet is determined largely by both the size and age of the American alligator and the size and availability of prey. Most American alligators will eat a wide variety of animals, including invertebrates, fish, birds, turtles, snakes, amphibians, and mammals. Hatchlings mostly feed on invertebrates such as insects, insect larvae, snails, spiders, and worms. As they grow, American alligators gradually expand to larger prey. Once an American alligator reaches full size and power in adulthood, any animal living in the water or coming to the water to drink is potential prey. Most animals captured by American alligators are considerably smaller than the American alligator itself. [18] Stomach contents show, among native mammals, muskrats and raccoons are some of the most commonly eaten species. [58] In Louisiana, where introduced coypu are common, they are perhaps the most regular prey for adult American alligators, although only larger adult American alligators commonly eat this species. [59] [58]

Large animals

Other animals may occasionally be eaten, even large deer or feral wild boars, but these are not normally part of the diet. American alligators will occasionally prey on large mammals, such as deer, but will usually do so when fish and smaller prey levels go down. [60] Rarely, American alligators have been observed killing and eating bobcats, but such events are not common and have little effect on bobcat populations. [61] [62] Although American alligators have been listed as predators of West Indian manatees, very little evidence exists of such predation. [63] In the 2000s, when invasive Burmese pythons occupied the Everglades, American alligators have been recorded preying on them, possibly controlling populations, thus preventing the invasive species from spreading northwards. [64] [65]

Domestic animals

Occasionally, domestic animals, including dogs, cats, and calves, are taken as available, but are secondary to wild and feral prey. [18] Other prey, including snakes, lizards, and various invertebrates, are eaten occasionally by adults. [16] Water birds, such as herons and egrets, storks, waterfowl and large dabbling rails such as gallinules or coots, are taken when possible. Occasionally, unwary adult birds are grabbed and eaten by American alligators, but most predation on bird species occur with unsteady fledgling birds in late summer as the prey of American alligators, as fledgling birds attempt to make their first flights near the water's edge. [16]

Fruit

In 2013, American alligators and other crocodilians were reported to also eat fruit. [66] Such behavior has been witnessed, as well as documented from stomach contents, with the American alligators eating such fruit as wild grapes, elderberries, and citrus fruits directly from the trees. The discovery of this unexpected part of the American alligator diet further reveals that American alligators may be responsible for spreading seeds from the fruit it digests across its habitat. [67] Additionally, American alligators engage in what seems to be cooperative hunting. [68] [69]

In Florida and East Texas

The diet of adult American alligators from central Florida lakes was dominated by fish, highly opportunistically based upon local availability. In Lake Griffin, fish made up 54% of the diet by weight, with catfish being most commonly consumed while in Lake Apopka, fish made up 90% of the food and mostly shad were taken and in Lake Woodruff the diet was 84% fish and largely consists of bass and sunfish. Unusually in these regions, reptiles and amphibians were the most important non-piscivore prey, mostly comprised by turtles and water snakes. [70] In southern Louisiana, crustaceans (largely crayfish and crabs) were found to be present in the southeastern American alligators but largely absent in the southwestern American alligator which consumed a relatively high proportion of reptiles, although fish were the most recorded prey for adult American alligators and adult males consumed a large portion of mammals. [71]

In East Texas, diets were diverse and adult American alligators took mammals, reptiles, amphibians and invertebrates (e.g. snails) in often equal measure as they did fish. [72]

Vocalizations

Mechanism

Alligators are able to abduct and adduct the vocal folds of their larynx, but not to elongate or shorten them - yet in spite of this, they can modulate fundamental frequency very well. [73]

Calls

Crocodilians are the most vocal of all reptiles and have a variety of different calls depending on the age, size, and gender of the animal. [74] The American alligator can perform specific vocalizations to declare territory, signal distress, threaten competitors, and locate suitable mates. Juvenile American alligators can perform a high-pitched hatchling call (a "yelping" trait common to many crocodilian species' hatchling young) [75] to alert their mothers when they are ready to emerge from the nest. Juveniles also make a distress call to alert their mothers if they are being threatened. Adult American alligators can growl, hiss, or cough to threaten others and declare territory.

Bellowing

Both males and females bellow loudly by sucking air into their lungs and blowing it out in intermittent, deep-toned roars in order to attract mates and declare territory. [76] Male alligators are known to use infrasound during mating bellows. Bellowing is performed in a "head oblique, tail arched" posture. Infrasonic waves from a bellowing male American alligator can cause the surface of the water directly over and to either side of its back to literally "sprinkle", [77] in what is commonly called the "water dance". [78] Large bellowing "choruses" of American alligators during the breeding season are commonly initiated by females and perpetuated by males. [79] Observers of large bellowing choruses have noted they are often felt more than they are heard due to the intense infrasound emitted by males. American alligators bellow in B flat (specifically "B♭1", defined as an audio frequency of 58.27 Hz), and bellowing choruses can be induced by tuba players, sonic booms, and large aircraft. [80]

Reproduction

Nest and young in Florida Crocnest.JPG
Nest and young in Florida
Young American alligator swimming, showing the distinctive yellow striping found on juveniles Alligator mississippiensis baby.jpg
Young American alligator swimming, showing the distinctive yellow striping found on juveniles

Breeding season

The breeding season begins in the spring. On spring nights, American alligators gather in large numbers for group courtship, in the aforementioned "alligator dances". [81] The female builds a nest of vegetation, sticks, leaves, and mud in a sheltered spot in or near the water.

Eggs

After the female lays her 20 to 50 white eggs, about the size of a goose egg, she covers them with more vegetation, which heats as it decays, helping to keep the eggs warm. This differs from Nile crocodiles, which lay their eggs in pits. [47] The temperature at which American alligator eggs develop determines their sex (see temperature-dependent sex determination). Those eggs which are hatched at a temperature of 93 °F (34 °C) or more become males, while those at a temperature of 86 °F (30 °C ) or lower become female. The nests built on levees are warmer and thus produce males, while the cooler nests of wet marsh produce females. [82] The female remains near the nest throughout the 65-day incubation period, protecting it from intruders. When the young begin to hatch — their "yelping" calls can sometimes even be heard just before hatching commences — the mother quickly digs them out and carries them to the water in her mouth, [18] as some other crocodilian species are known to do.

Young

The young are tiny replicas of adult American alligators with a series of yellow bands around their bodies that serve as camouflage. [18] Hatchlings gather into pods and are guarded by their mother and keep in contact with her through their "yelping" vocalizations. Young American alligators eat small fish, frogs, crayfish, and insects. [83] They are preyed on by large fish, birds, raccoons, and adult American alligators. [18] Mother American alligators eventually become more aggressive towards their young, which encourages them to disperse. [83] Young American alligators grow 3–8 in (7.6–20.3 cm) a year and reach adulthood at 6 ft (1.8 m). [45]

Interactions with exotic species

Nutria were introduced into coastal marshes from South America in the mid-20th century, and their population has since exploded into the millions. They cause serious damage to coastal marshes and may dig burrows in levees. Hence, Louisiana has had a bounty to try to reduce nutria numbers. Large American alligators feed heavily on nutria, so American alligators may not only control nutria populations in Louisiana, but also prevent them spreading east into the Everglades. Since hunting and trapping preferentially take the large American alligators that are the most important in eating nutria, some changes in harvesting may be needed to capitalize on their ability to control nutria. [59]

Recently, a population of Burmese pythons became established in Everglades National Park. Substantial American alligator populations in the Everglades may be a contributing factor in keeping the python populations low, preventing the spread of the species up north. While events of predation by Burmese pythons on young American alligators have been observed, no evidence of a net negative effect has been seen on overall American alligator populations. [84] [85] [86]

American alligator predation on Florida panthers is rare, but has been documented. Such incidents usually involve a panther trying to cross a waterway or coming down to a swamp or river to get a drink. The American alligator is the only known natural predator of the panther. [87] American alligator predation on American black bears has also been recorded. [88] [89] [90]

Indicators of environmental restoration

American alligators play an important role in the restoration of the Everglades as biological indicators of restoration success. [91] American alligators are highly sensitive to changes in the hydrology, salinity, and productivity of their ecosystems; all are factors that are expected to change with Everglades restoration. American alligators also may control the long-term vegetation dynamics in wetlands by reducing the population of small mammals, particularly coypu, which may otherwise overgraze marsh vegetation. [59] In this way, the vital ecological service they provide may be important in reducing rates of coastal wetland losses in Louisiana. [92] They may provide a protection service for water birds nesting on islands in freshwater wetlands. American alligators prevent predatory mammals from reaching island-based rookeries and in return eat spilled food and birds that fall from their nests. Wading birds appear to be attracted to areas with American alligators and have been known to nest at heavily trafficked tourist attractions with large numbers of American alligators, such as the St. Augustine Alligator Farm in St. Augustine, Florida. [93]

Conservation status

Historically, hunting and habitat loss have severely impacted American alligator populations throughout their range, and whether the species would survive was in doubt. In 1967, the American alligator was listed as an endangered species (under a law that was the precursor Endangered Species Act of 1973), since it was believed to be in danger of extinction throughout all or a significant portion of its range. [94]

Both the United States Fish and Wildlife Service (USFWS) and state wildlife agencies in the South contributed to the American alligator's recovery. Protection under the Endangered Species Act allowed the species to recuperate in many areas where it had been depleted. States began monitoring their American alligator populations to ensure that they would continue to grow. In 1987, the USFWS removed the animal from the endangered species list, as it was considered to be fully recovered. The USFWS still regulates the legal trade in American alligators and their products to protect still endangered crocodilians that may be passed off as American alligators during trafficking. [94]

Relationship with humans

Attacks on humans

Defensive American alligator with mouth open Alligator mississippiensis defensive.jpg
Defensive American alligator with mouth open

American alligators are capable of killing humans but fatal attacks are fairly rare. Mistaken identity leading to an attack is always possible, especially in or near cloudy waters. American alligators are often less aggressive towards humans than larger crocodile species, a few of which (mainly the Nile and Saltwater crocodiles) may prey on humans with some regularity. [17] [95] American alligator bites are serious injuries due to the reptile's sheer bite force and risk of infection. Even with medical treatment, an American alligator bite may still result in a fatal infection. [96]

As human populations increase, and as they build houses in low-lying areas or fish or hunt near water, incidents are inevitable where American alligators intrude, or at least appear to intrude, on human life. Since 1948, 257 documented attacks on humans in Florida (about five incidents per year) have been reported, of which an estimated 23 resulted in death. [97] Only nine fatal attacks occurred in the United States throughout the 1970s–1990s, but American alligators killed 12 people between 2001 and 2007. In May 2006, American alligators killed three Floridians in less than a week. [98] There have been at least 28 fatal attacks by American alligators in the United States since 1970.

Wrestling

Man wrestling American alligator GilletteAlligatorWrestling.jpg
Man wrestling American alligator

Since the late 1880s, alligator wrestling has been a source of entertainment for some. Created by the Miccosukee and Seminole tribes prior to the arrival of Europeans, this tourism tradition continues to persist despite criticism from animal rights activists. [99]

Farming

Today, alligator farming is a large, growing industry in Georgia, Florida, Texas, and Louisiana. These states produce a combined annual total of some 45,000 alligator hides. Alligator hides bring good prices and hides in the 6 to 7-ft range have sold for $300 each. [100] The market for alligator meat is growing, and about 300,000 pounds (140,000 kg) of meat is produced annually. [101] According to the Florida Department of Agriculture and Consumer Services, raw alligator meat contains roughly 200 Calories (840 kJ) per 3-oz (85-g) serving, of which 27 Calories (130 kJ) come from fat.

Culture

The American alligator is the official state reptile of Florida, [102] Louisiana, [103] and Mississippi. [104] Several organizations and products from Florida have been named after the animal.

"Gators" has been the nickname of the University of Florida's sports teams since 1911. In that year, a printer made a spur-of-the-moment decision to print an alligator emblem on a shipment of the school's football pennants. The mascot stuck, perhaps because the team captain's nickname was Gator. [105] Allegheny College and San Francisco State University both have Gators as their mascots as well. [106]

The Gator Bowl is a college football game held in Jacksonville annually since 1946, with Gator Bowl Stadium hosting the event until the 1993 edition. The Gatornationals is a NHRA drag race held at the Gainesville Raceway in Gainesville since 1970.

See also

Notes

  1. Crocodile Specialist Group (1996). "Alligator mississippiensis". The IUCN Red List of Threatened Species . 1996: e.T46583A11061981. doi:10.2305/IUCN.UK.1996.RLTS.T46583A11061981.en . Retrieved November 10, 2017.
  2. "Alligator mississippiensis". The Reptile Database. www.reptile-database.com.
  3. Vilet, Kent (1989). "Social Displays of the American Alligator (Alligator mississippiensis)". American Zoology. 2 (3): 1019–1031. doi:10.1093/icb/29.3.1019.
  4. Pajerski, Lauren; Schechter, Benjamin; Street, Robin (2000). "Alligator mississippiensis". University of Michigan Museum of Zoology.
  5. Alligator Cuvier, 1807. ITIS.gov
  6. Brochu, Christopher A. (2003). "Phylogenetic approaches toward crocodylian history" (PDF). Annual Review of Earth and Planetary Sciences. 31: 357–97. doi:10.1146/annurev.earth.31.100901.141308.[ permanent dead link ]
  7. Brochu, Christopher A. (1999). "Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea". Society of Vertebrate Paleontology Memoir. 6: 9–100. doi:10.2307/3889340. JSTOR   3889340.
  8. Whiting, Evan T.; Steadman, David W.; Vliet, Kent A. (June 1, 2016). "Cranial Polymorphism and Systematics of Miocene and Living Alligator in North America". Journal of Herpetology. 50 (2): 306–315. doi:10.1670/15-023. ISSN   0022-1511.
  9. Janke, A.; Arnason, U. (1997). "The complete mitochondrial genome of Alligator mississippiensis and the separation between recent archosauria (birds and crocodiles)". Molecular Biology and Evolution. 14 (12): 1266–72. doi:10.1093/oxfordjournals.molbev.a025736. PMID   9402737.
  10. Green RE, Braun EL, Armstrong J, Earl D, Nguyen N, Hickey G, Vandewege MW, St John JA, Capella-Gutiérrez S, Castoe TA, Kern C, Fujita MK, Opazo JC, Jurka J, Kojima KK, Caballero J, Hubley RM, Smit AF, Platt RN, Lavoie CA, Ramakodi MP, Finger JW, Suh A, Isberg SR, Miles L, Chong AY, Jaratlerdsiri W, Gongora J, Moran C, Iriarte A, McCormack J, Burgess SC, Edwards SV, Lyons E, Williams C, Breen M, Howard JT, Gresham CR, Peterson DG, Schmitz J, Pollock DD, Haussler D, Triplett EW, Zhang G, Irie N, Jarvis ED, Brochu CA, Schmidt CJ, McCarthy FM, Faircloth BC, Hoffmann FG, Glenn TC, Gabaldón T, Paten B, Ray DA (2014). "Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs". Science. 346 (6215): 1254449. doi:10.1126/science.1254449. PMC   4386873 . PMID   25504731.
  11. Thorbjarnarson, J. B. (2010). Black caiman Melanosuchus niger. Crocodiles. Status Survey and Conservation Action Plan, 29–39.
  12. 1 2 Woodward, A. R.; White, J. H. & Linda, S. B. (1995). "Maximum size of the alligator (Alligator mississippiensis)". Journal of Herpetology. 29 (4): 507–513. doi:10.2307/1564733. JSTOR   1564733.
  13. Clippinger, T. L.; Avery Bennett, R.; Johnson, C. M.; Vliet, K. A.; Deem, S. L.; Orós, J.; Brown, M. B. (2000). "Morbidity and mortality associated with a new mycoplasma species from captive American alligators (Alligator mississippiensis)". Journal of Zoo and Wildlife Medicine. 31 (3): 303–314. doi:10.1638/1042-7260(2000)031[0303:mamawa]2.0.co;2. PMID   11237136.
  14. American Alligators, American Alligator Pictures, American Alligator Facts – National Geographic. Animals.nationalgeographic.com.
  15. American alligator Archived April 11, 2013, at the Wayback Machine . Philadelphia Zoo.
  16. 1 2 3 4 Charles, S.; Ross, A. and Garnett, Stephen (1989) Crocodiles and Alligators. Checkmark Books. ISBN   978-0-8160-2174-1.
  17. 1 2 3 Wood, Gerald (1983). The Guinness Book of Animal Facts and Feats. ISBN   978-0-85112-235-9.
  18. 1 2 3 4 5 6 7 8 "Crocodilian Species—American Alligator (Alligator mississippiensis)". Flmnh.ufl.edu. Retrieved October 14, 2008.
  19. Smith, E. N.; Standora, E. A. & Robertson, S. L. (1984). "Physiological thermoregulation of mature alligators". Comparative Biochemistry and Physiology. A, Comparative Physiology. 77 (1): 189–93. doi:10.1016/0300-9629(84)90033-1. PMID   6141029.
  20. "Record gator caught in Southwest Arkansas". FoxNews.com. Retrieved March 15, 2014.
  21. Everglades National Park Flora & Fauna Page. Everglades National Park
  22. Florida alligator. Floridaadventuring.com (March 2, 2016). Retrieved on 2016-09-07.
  23. "American Alligator". www.animalspot.net. Retrieved April 24, 2017.
  24. "Gator factsheet" (PDF). Savannah River Ecology Laboratory. Retrieved August 14, 2012.
  25. "American Alligator Fact Sheet". The National Zoo. Retrieved December 30, 2013.
  26. 1 2 Goodwin, Thomas M. (1979). "Seasonal activity ranges and habitat preferences of adult alligators in a north-central Florida lake". Journal of Hepatology. 13 (2): 157–64. doi:10.2307/1563922. JSTOR   1563922.
  27. Honeyfield, D. C.; Ross, J. P.; Carbonneau, D. A.; Terrell, S. P.; Woodward, A. R.; Schoeb, T. R.; Hinterkopf, J. P. (2008). "Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis)". Journal of Wildlife Diseases. 44 (2): 280–294. doi:10.7589/0090-3558-44.2.280. PMID   18436661.
  28. Ruben, J. A.; Jones, T. D. (2000). "Selective factors associated with the origin of fur and feathers". American Zoologist. 40 (4): 585–596. doi:10.1668/0003-1569(2000)040[0585:sfawto]2.0.co;2.
  29. Saalfeld, D. T.; Webb, K. K.; Conway, W. C.; Calkins, G. E.; Duguay, J. P. (2008). "Growth and condition of American alligators (Alligator mississippiensis) in an inland wetland of east Texas". Southeastern Naturalist. 7 (3): 541–550. doi:10.1656/1528-7092-7.3.541.
  30. Webb, GJW.; Messel, H. (1978). "Morphometric analysis of Crocodylus porosus from the north coast of Arnhem Land, northern Australia". Australian Journal of Zoology. 26 (1): 1–27. doi:10.1071/zo9780001.
  31. Lance, V. A.; Elsey, R. M.; Lang, J. W. (2000). "Sex ratios of American alligators (Crocodylidae): male or female biased?". Journal of Zoology. 252 (1): 71–78. doi:10.1017/s0952836900009080.
  32. "American Alligator: Species Profile". US National Park Service. Retrieved August 14, 2012.
  33. "Zoo keeps albino alligator in the dark". NBC News.com. May 11, 2007. Retrieved August 15, 2012.
  34. 1 2 3 4 Erickson, Gregory M.; Lappin, A. Kristopher; Vliet, Kent A. (March 2003). "The ontogeny of bite-force performance in American alligator (Alligator mississippiensis)". Journal of Zoology. 260 (3): 317–327. doi:10.1017/s0952836903003819. ISSN   0952-8369.
  35. Erickson, Gregory M.; Lappin, A. Kristopher; Parker, Trevor; Vliet, Kent A. (2004). "Comparison of bite-force performance between long-term captive and wild American alligators (Alligator mississippiensis)" (PDF). Journal of Zoology . 262 (1): 21–28. doi:10.1017/S0952836903004400.
  36. Erickson, GM; Gignac PM; Steppan SJ; Lappin AK; Vliet KA; et al. (2012). "Insights into the Ecology and Evolutionary Success of Crocodilians Revealed through Bite-Force and Tooth-Pressure Experimentation". PLoS ONE. 7 (3): e31781. doi:10.1371/journal.pone.0031781. PMC   3303775 . PMID   22431965.
  37. Reilly, S. M.; Elias, J. A. (1998). "Locomotion in alligator mississippiensis: kinematic effects of speed and posture and their relevance to the sprawling-to-erect paradigm" (PDF). The Journal of Experimental Biology . 201 (18): 2559–74. PMID   9716509.
  38. Fish, F. E. (1984). "Kinematics of undulatory swimming in the American alligator" (PDF). Copeia. 1984 (4): 839–43. doi:10.2307/1445326. JSTOR   1445326. Archived from the original (PDF) on October 21, 2013.
  39. Farmer, C. G.; Sanders, K. (2010). "Unidirectional airflow in the lungs of American alligators". Science. 327 (5963): 338–340. doi:10.1126/science.1180219. PMID   20075253.
  40. Uriona, T. J.; Farmer, C. G. (2008). "Recruitment of the diaphragmaticus, ischiopubis and other respiratory muscles to control pitch and roll in the American alligator (Alligator mississippiensis)". Journal of Experimental Biology . 211 (7): 1141–11477. doi:10.1242/jeb.015339. PMID   18344489.
  41. "SEARCHING FOR THE NORTHERN AND SOUTHERN DISTRIBUTION LIMITS OF TWO CROCODILIAN SPECIES: Alligator mississippiensis AND Crocodylus moreletii IN SOUTH TEXAS, US, AND IN NORTHERN TAMAULIPAS, MEXICO" . Retrieved August 16, 2018.
  42. Tennessee Wildlife Resources Agency - Alligators. , accessed March 28, 2018
  43. "NAS - Nonindigenous Aquatic Species: Alligator mississippiensis". USGS.
  44. "Elusive Chattahoochee alligator caught in Cobb County". myajc. Retrieved December 17, 2016.
  45. 1 2 3 "American Alligator (Alligator mississippiensis)". Savannah River Ecology Lab. Retrieved August 16, 2012.
  46. "What's the difference between a crocodile and an alligator?". Flmnh.ufl.edu. Retrieved August 26, 2012.
  47. 1 2 3 Guggisberg, C.A.W. (1972). Crocodiles: Their Natural History, Folklore, and Conservation. Newton Abbot: David & Charles. p. 195. ISBN   978-0-7153-5272-4.
  48. Lance, Valentine A. (2003). "Alligator physiology and life history: the importance of temperature". Experimental Gerontology. 38 (7): 801–805. doi:10.1016/S0531-5565(03)00112-8. PMID   12855291.
  49. Dinets, Vladimir; Britton, Adam; Shirley, Matthew (2013). "Climbing behaviour in extant crocodilians" (PDF). Herpetology Notes. 7: 3–7. (published online January 25, 2014)
  50. Rice, Ken G.; Mazzotti, Frank (October 2005). "American Alligator Ecology and Monitoring for the Comprehensive Everglades Restoration Plan" (PDF). University of Florida IFAS Extension.
  51. Campell, Mark R.; Mazzotti, Frank J. (2004). "Characterization of Natural and Artificial Alligator Holes" (PDF). Southeastern Naturalist. 3 (4): 583–94. doi:10.1656/1528-7092(2004)003[0583:CONAAA]2.0.CO;2.[ permanent dead link ]
  52. WEC203/UW230: Living with Alligators: A Florida Reality. Edis.ifas.ufl.edu. Retrieved on August 21, 2012.
  53. Dinets, V; Brueggen, JC; Brueggen, J.D. (2013). "Crocodilians use tools for hunting". Ethology, Ecology and Evolution. 1: 74–78. doi:10.1080/03949370.2013.858276.
  54. "Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey". ScienceDaily. December 4, 2013. Retrieved December 8, 2013.
  55. Dinets, V. L. (2011). "On terrestrial hunting in crocodilians" (PDF). Herpetological Bulletin. 114: 15–18. Archived from the original (PDF) on October 15, 2011.
  56. Jason Bittel (September 20, 2017). "Alligators Attack and Eat Sharks, Study Confirms". National Geographic.
  57. Nifong, James C.; Lowers, Russell H. (2017). "Reciprocal Intraguild Predation between Alligator mississippiensis (American Alligator) and Elasmobranchii in the Southeastern United States". Outheastern Naturalist. 16 (3): 383–396. doi:10.1656/058.016.0306.
  58. 1 2 Valentine Jr, J. M.; Walther, J. R.; McCartney, K. M.; Ivy, L. M. (1972). "Alligator diets on the Sabine National Wildlife Refuge, Louisiana". The Journal of Wildlife Management. 36 (3): 809–815. doi:10.2307/3799434. JSTOR   3799434.
  59. 1 2 3 Keddy, P.A., L. Gough, J.A. Nyman, T. McFalls, J. Carter and J. Siegrist (2009). Alligator hunters, pelt traders, and runaway consumption of Gulf coast marshes: A trophic cascade perspective on coastal wetland losses. pp. 115–133 in B.R. Silliman, E.D. Grosholz, and M.D. Bertness (eds.) Human Impacts on Salt Marshes. A Global Perspective. University of California Press, Berkeley, CA ISBN   0-520-25892-4 Google Books
  60. "American Alligator". News Daily. Archived from the original on March 18, 2015. Retrieved February 28, 2018.
  61. "Gator eats bobcat". Flickr. November 7, 2012. Retrieved November 7, 2012.
  62. "Sneaky alligator nearly eats bobcat". Kens5. Archived from the original on January 11, 2014. Retrieved June 1, 2012.
  63. Whitaker, John O. (1996). The Audubon Society Field Guide to North American Mammals. New York, pg. 808. ISBN   978-0-679-44631-6.
  64. Dorcas, M. E.; Willson, J. D.; Reed, R. N.; Snow, R. W.; Rochford, M. R.; Miller, M. A.; Hart, K. M. (2012). "Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park". Proceedings of the National Academy of Sciences. 109 (7): 2418–2422. doi:10.1073/pnas.1115226109. PMC   3289325 . PMID   22308381.
  65. Nolen, R. S. (2012). "How big is Florida's python problem?". J Am Vet Med Assoc. 240 (7): 778–782. doi:10.2460/javma.240.7.778. PMID   22443430.
  66. Choi, Charles Q. (August 30, 2013). "Crocodiles and alligators like to chomp down on ... fruit !". NBC News: Science. Retrieved August 31, 2013.
  67. Platt, S.G; Elsey, R.M; Liu, H. (2013). "Frugivory and seed dispersal by crocodilians: an overlooked form of saurochory?". Journal of Zoology. 291 (2): 87. doi:10.1111/jzo.12052.
  68. F. Wayne King, John Thorbjarnarson and Carlos Yamashita. 1998. Cooperative Feeding, A Misinterpreted and Under-Reported Behavior of Crocodilians. 9 p. Available at: http://www.flmnh.ufl.edu/herpetology/links/cooperative-feeding (Online: 1 August 1998)
  69. Dinets, Vladmir (2014). "Apparent coordination and collaboration in cooperatively hunting crocodilians". Ethology Ecology & Evolution. 27 (2): 244–250. doi:10.1080/03949370.2014.915432.
  70. Rice, A. N. (2004). Diet and condition of American alligators (Alligator mississippiensis) in three central Florida lakes (Doctoral dissertation, University of Florida).
  71. Gabrey, S. W. (2010). "Demographic and geographic variation in food habits of American alligators (Alligator mississippiensis) in Louisiana" (PDF). Herpetological Conservation and Biology. 5 (2): 241–250.
  72. Saalfeld, D. T.; Conway, W. C.; Calkins, G. E. (2011). "Food Habits of American Alligators (Alligator mississippiensis) in East Texas". Southeastern Naturalist. 10 (4): 659–672. doi:10.1656/058.010.0406.
  73. Riede, T; Tokuda, I. T.; Farmer, C. G. (2011). "Subglottal pressure and fundamental frequency control in contact calls of juvenile Alligator mississippiensis". Journal of Experimental Biology. 214 (Pt 18): 3082–95. doi:10.1242/jeb.051110. PMC   3160820 . PMID   21865521.
  74. Britton, Adam. "Crocodile Talk". University of Bristol and Florida Museum of Natural History.
  75. "Yelping" of alligator hatchlings. YouTube.com (September 3, 2013). Retrieved on 2016-09-07.
  76. https://defenders.org/american-alligator/basic-fact
  77. Male alligator "sprinkling" while bellowing in near-infrasound during courtship. YouTube.com (April 28, 2010). Retrieved on 2016-09-07.
  78. Garrick, L. D.; Lang, J. W. (1977). "Social Displays of the American Alligator". American Zoologist. 17: 225–239. doi:10.1093/icb/17.1.225.
  79. Garrick, L.; Lang, J.; Herzog, H. (1978). "Social Signals of Adult American Alligators". 60 (3): 153–192.
  80. Kilnkenberg, Jeff (June 21, 2013). "Alligators in B Flat? Gatorland's denizens roar in ecstasy". Tampa Bay Times. "We want to hit the B flat two octaves below middle C, " Mickelsen reminded his young assistant. "At 57 hertz. That's what that old scientific report advised...BLAAAA!...Though only a few clouds scudded across the sky, we heard what sounded like thunder in the distance. It was a randy male American alligator, turned on by tuba, telling the world that he was a stud...He lifted his upper body out of the water while lowering the middle and raising his tail. Though he barely moved, a droplet spray exploded from the water covering his back. "The water dance!" Tim Williams cried. Toxic let loose a roar that shook the earth.
  81. Dinets, V. L. (2010). "Nocturnal behavior of the American Alligator (Alligator mississippiensis) in the wild during the mating season". Herpetological Bulletin. 111: 4–11.
  82. Joanen, T.; Ferguson, M. W. J. (1982). "Temperature of egg incubation determines sex in Alligator mississippiensis". Nature. 296 (5860): 850–53. doi:10.1038/296850a0. PMID   7070524.
  83. 1 2 Hunt, R. H.; Watanabe, M. E. (1982). "Observations on the maternal behavior of the American alligator, Alligator mississippiensis". Journal of Herpetology. 16 (3): 235–39. doi:10.2307/1563716. JSTOR   1563716.
  84. Gator-guzzling python comes to messy end. Associated Press (October 5, 2005). Retrieved 2008-03-11.
  85. Butler, Rhett A. (October 5, 2005) Python explodes after swallowing 6-foot alligator in Florida Everglades. Mongabay.com. Retrieved 2008-03-11.
  86. United States Department of the Interior, U.S. Geological Survey (February 20, 2008). USGS Maps Show Potential Non-Native Python Habitat Along Three U.S. Coasts. www.usgs.gov. Retrieved 2008-03-11.
  87. Sivlerstein, Alvin (1997). The Florida Panther. Brooksville, Connecticut: Millbrook Press. pp. 41+. ISBN   0-7613-0049-X.
  88. "American Alligator". Animal List.
  89. "Alligators". Aquatic Community.
  90. "Key West Florida Attractions | Alligator Exhibit". Key West Aquarium. Retrieved December 20, 2012.
  91. Harvey, Rebecca G.; Brandt, Laura A.; Mazzotti, Frank J. (October 2011). "The American Alligator: An Indicator Species for Everglades Restoration" (PDF). University of Florida IFAS Extension.
  92. Keddy, P.A. (2010). Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. ISBN   0-521-78367-4.
  93. White, C.; Frederick, P.; Main, M.; Rodgers, J. (May 2005). "Nesting Island Creation for Wading Birds" (PDF). University of Florida IFAS Extension.
  94. 1 2 "American Alligator Alligator mississippiensis" (PDF). U.S. Fish and Wildlife Service. February 2008. Retrieved September 3, 2012.
  95. Crocodile and Alligator Differences – Animal Facts for Kids. Sciencekids.co.nz (July 11, 2012). Retrieved on 2012-08-21.
  96. Harding, Brett E.; Wolf, Barbara C. (2006). "Alligator Attacks in Southwest Florida". Journal of Forensic Sciences. 51 (3): 674–677. doi:10.1111/j.1556-4029.2006.00135.x. PMID   16696720.
  97. McLaughlin, Eliott C.; Almasy, Steve and Shoichet, Catherine E. (2016-06-16) Disney alligator attack: Resort to add warning signs, source says. CNN
  98. "A String of Deaths by Gators in Florida". nytimes.com. May 15, 2006. Retrieved May 15, 2006.
  99. "Alligator wrestling – cruelty or tradition?". BBC News.com. March 17, 2009. Retrieved August 29, 2012.
  100. Lane, Thomas J.; Ruppert, Kathleen C. (June 2008). "Alternative Opportunities for Small Farms:Alligator Production Review" (PDF). University of Florida. Retrieved August 29, 2012.
  101. Reig Eimeric (2006). "Gator Maters: Florida farmers find lucrative business mating alligators". Orange and Blue Magazine. Archived from the original on May 30, 2013. Retrieved August 29, 2012.
  102. "Alligator". Florida State Symbols. Florida Division of Historical Resources. 2013. Retrieved April 6, 2013.
  103. "About Louisiana". Louisiana.gov. State of Louisiana. Retrieved April 6, 2013.
  104. Act No. 302 of July 1, 2005 (PDF). Retrieved April 6, 2013.
  105. "History: 1906–1927, early Gainesville". University of Florida. Archived from the original on December 31, 2010. Retrieved February 13, 2011.
  106. "Why Gators?". Allegheny College. Retrieved March 30, 2019.

Further reading

Related Research Articles

Alligatoridae family of large reptiles

The family Alligatoridae of crocodylians includes alligators and caimans.

Crocodile Subfamily of large reptilian carnivores

Crocodiles or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, all of whose members are considered true crocodiles, is classified as a biological subfamily. A broader sense of the term crocodile, Crocodylidae that includes Tomistoma, is not used in this article. The term crocodile here applies to only the species within the subfamily of Crocodylinae. The term is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans, the gharial and false gharial, and all other living and fossil Crocodylomorpha.

Crocodilia Order of large reptiles

Crocodilia is an order of mostly large, predatory, semiaquatic archosaurian reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the order's total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period, and diversified during the Mesozoic era. The order Crocodilia includes the true crocodiles, the alligators and caimans, and the gharial and false gharial. Although the term 'crocodiles' is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group.

Alligator Genus of large reptiles

An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. The two living species are the American alligator and the Chinese alligator. Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the Oligocene epoch about 37 million years ago.

<i>Caiman</i> (genus) genus of reptiles

Caiman is a genus of caimans within the alligatorid subfamily Caimaninae. They inhabit Central and South America. They are relatively small sized crocodilians, with all species reaching lengths of only a few meters and weighing 6 to 40 kg on average.

Saltwater crocodile species of crocodile

The saltwater crocodile is a crocodilian native to saltwater habitats and brackish wetlands from India's east coast across Southeast Asia and the Sundaic region to northern Australia and Micronesia. It is among the largest crocodiles and regarded as dangerous by people who share the same environment. It was hunted for its skin throughout its range up to the 1970s, and is threatened by illegal killing and habitat loss.

Black caiman species of reptile

The black caiman is a species of large crocodilian and, along with the American alligator, is one of the biggest extant members of the family Alligatoridae and order Crocodilia. It is a carnivorous reptile that lives along slow-moving rivers, lakes, seasonally flooded savannas of the Amazon basin, and in other freshwater habitats of South America. It is a quite large species, growing to at least 5 m (16 ft) and possibly up to 6 m (20 ft) in length, which makes it the second largest reptile in the Neotropical ecozone, next to the critically endangered Orinoco crocodile. As its common and scientific names imply, the black caiman has a dark coloration, as an adult. In some individuals, the dark coloration can appear almost black. It has grey to brown banding on the lower jaw. Juveniles have a more vibrant coloration compared to adults with prominent white to pale yellow banding on the flanks that remains present well into adulthood, at least more when compared to other species. The morphology is quite different from other caimans but the bony ridge that occurs in other caimans is present. The head is large and heavy, an advantage in catching larger prey.

Nile crocodile species of reptile

The Nile crocodile is an African crocodile, the largest freshwater predator in Africa, and may be considered the second-largest extant reptile and crocodilian in the world, after the saltwater crocodile. The Nile crocodile is quite widespread throughout sub-Saharan Africa, occurring mostly in the central, eastern, and southern regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, and marshlands. Although capable of living in saline environments, this species is rarely found in saltwater, but occasionally inhabits deltas and brackish lakes. The range of this species once stretched northward throughout the Nile, as far north as the Nile delta. On average, the adult male Nile crocodile is between 3.5 and 5 m in length and weighs 225 to 750 kg. However, specimens exceeding 6.1 m (20 ft) in length and weighing up to 1,090 kg (2,400 lb) have been recorded. Sexual dimorphism is prevalent, and females are usually about 30% smaller than males. They have thick, scaly, heavily armored skin.

American crocodile Species of reptile

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, with populations present from South Florida and the coasts of Mexico to as far south as Peru and Venezuela.

Freshwater crocodile species of reptile

The freshwater crocodile, also known as the Australian freshwater crocodile, Johnstone's crocodile or colloquially as freshie, is a species of crocodile endemic to the northern regions of Australia.

Nile monitor species of reptile

The Nile monitor is a large member of the monitor family (Varanidae) found throughout much of Africa, but is absent from the west, where it is replaced by Varanus stellatus. Other common names include the African small-grain lizard, water leguaan or river leguaan.

Orinoco crocodile species of reptile

The Orinoco crocodile is a critically endangered crocodile. Its population is very small and it can only be found in freshwater environments in Colombia and Venezuela, in particular the Orinoco river and its tributaries. Extensively hunted for their skins in the 19th and 20th centuries, this species is one of the most critically endangered species of crocodiles. It is a very large species of crocodilian and predator in the Americas. Males have been reported up to 6.8 m in the past, but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.1 m in length and can weigh 380 kg (840 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in some other species. The coloration is light even in adults.

Cuviers dwarf caiman species of reptile

Cuvier's dwarf caiman is a small crocodilian in the alligator family from northern and central South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela. It lives in riverine forests, flooded forests near lakes, and near fast-flowing rivers and streams. It can traverse dry land to reach temporary pools and tolerates colder water than other species of caimans. Other common names for this species include the musky caiman, the dwarf caiman, Cuvier's caiman, and the smooth-fronted caiman. It is sometimes kept in captivity as a pet and may be referred to as the wedge-head caiman by the pet trade.

New Guinea crocodile species of reptile

The New Guinea crocodile is a small species of crocodile found on the island of New Guinea where there are two geographically isolated populations to the north and south of the mountain ridge that runs along the centre of the island. In the past it included the Philippine crocodile, C. n. mindorensis, as a subspecies, but today they are regarded as separate species. The habitat of the New Guinea crocodile is mostly freshwater swamps and lakes. It is most active at night when it feeds on fish and a range of other small animals. A female crocodile lays a clutch of eggs in a nest composed of vegetation and she lies up nearby to guard the nest. There is some degree of parental care for newly hatched juveniles. This crocodile was over-hunted for its valuable skin in the mid 20th century, but conservation measures have since been put in place, it is reared in ranches and the International Union for Conservation of Nature (IUCN) lists it as being of "Least Concern".

Morelets crocodile species of reptile

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.

Spectacled caiman species of reptile

The spectacled caiman, also known as the white caiman, common caiman, and speckled caiman, is a crocodilian in the family Alligatoridae. It is brownish-, greenish-, or yellowish-gray colored and has a spectacle-like ridge between its eyes, which is where its common name come from. It grows to a length of 1.4–2.5 metres (4.6–8.2 ft) and a weight of 7–40 kilograms (15–88 lb), with males being both longer and heavier than females. Its diet varies seasonally, commonly consisting of crabs, fish, mammals, and snails. Breeding occurs from May to August and 14–40 eggs are laid in July and August. This crocodilian has a large range and population, native to much of Latin American and introduced to the United States.

Caiman Subfamily of reptiles

A caiman is a crocodilian alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within Alligatoridae, the other being alligators.

Crocodile farm establishment for breeding and raising of crocodilians

A crocodile farm or alligator farm is an establishment for breeding and raising of crocodilians in order to produce crocodile and alligator meat, leather, and other goods. Many species of both alligators and crocodiles are farmed internationally. In Louisiana alone, alligator farming is a $60 to $70 million industry.

Cuban crocodile species of reptile

The Cuban crocodile is a small species of crocodile found only in Cuba. Typical length is 2.1–2.3 m (6.9–7.5 ft) and typical weight 70–80 kg (150–180 lb). Large males can reach as much as 3.5 m (11 ft) in length and weigh more than 215 kg (474 lb). Despite its modest size, it is a highly aggressive animal, and potentially dangerous to humans.

Vladimir Dinets zoologist

Vladimir Dinets is a zoologist and author, known for his studies of Crocodilian behavior and of numerous rare animals in remote parts of the world, as well as for popular writings in Russian and English.