:American alligator

The American alligator was first classified in 1801 by French zoologist François Marie Daudin as Crocodilus mississipiensis. In 1807, Georges Cuvier created the genus Alligator for it,[https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=174366 Alligator Cuvier, 1807]. ITIS.gov based on the English common name alligator (derived from Spanish word {{lang|es|el lagarto}}, "the lizard").

The American alligator and its closest living relative, the Chinese alligator, belong the subfamily Alligatorinae. Alligatorinae is the sister group to the caimans of Caimaninae, which together comprise the family Alligatoridae, which can be shown in the cladogram below:{{Cite journal | last1 = Hastings | first1 = A. K. | last2 = Bloch | first2 = J. I. | last3 = Jaramillo | first3 = C. A. | last4 = Rincon | first4 = A. F. | last5 = MacFadden | first5 = B. J. | title = Systematics and biogeography of crocodylians from the Miocene of Panama | doi = 10.1080/02724634.2012.713814 | journal = Journal of Vertebrate Paleontology | volume = 33 | issue = 2 | pages = 239 | year = 2013 | bibcode = 2013JVPal..33..239H | s2cid = 83972694 | doi-access = free }}{{Cite journal | last1 = Brochu | first1 = C. A. | doi = 10.1111/j.1096-3642.2011.00716.x | title = Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines | journal = Zoological Journal of the Linnean Society | volume = 163 | pages = S228–S256 | year = 2011 | doi-access = free }}

{{clade| style=font-size:85%;line-height:85%

|label1=Alligatoridae

|1={{clade

|1=Caimaninae

|label2=Alligatorinae

|2={{clade

|1=Ceratosuchus burdoshi{{extinct}}

|2=Hassiacosuchus haupti{{extinct}}

|3=Navajosuchus mooki{{extinct}}

|4={{clade

|1=Wannaganosuchus brachymanus{{extinct}}

|2=Arambourgia gaudryi{{extinct}}

|3={{clade

|1=Allognathosuchus polyodon{{extinct}}

|2=Allognathosuchus wartheni{{extinct}}

|3=Procaimanoidea kayi{{extinct}} }}

|label4=Alligator

|4={{clade

|1=Alligator prenasalis{{extinct}}

|2={{clade

|1=Alligator mcgrewi{{extinct}}

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|1=Alligator olseni{{extinct}}

|2={{clade

|1=Alligator sinensis Chinese alligator

|2={{clade

|1=Alligator thomsoni{{extinct}}

|2=Alligator mefferdi{{extinct}}

|3=Alligator mississippiensis American alligator }} }} }} }} }} }} }} }} }}

File:AlligatorFL2007.JPG]]

Fossils identical to the existing American alligator are found throughout the Pleistocene, from 2.5 million to 11.7 thousand years ago.{{cite journal|doi=10.2307/3889340|title=Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea|last=Brochu|first=Christopher A.|journal=Society of Vertebrate Paleontology Memoir|volume=6|year=1999|pages=9–100|jstor=3889340}} In 2016, a Late Miocene fossil skull of an alligator, dating to approximately seven or eight million years ago, was discovered in Marion County, Florida. Unlike the other extinct alligator species of 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, suggesting that the A. mississippiensis lineage has existed in North America for seven to eight million years.{{Cite journal |last1=Whiting |first1=Evan T. |last2=Steadman |first2=David W. |last3=Vliet |first3=Kent A. |date=June 1, 2016 |title=Cranial Polymorphism and Systematics of Miocene and Living Alligator in North America|journal=Journal of Herpetology |volume=50 |issue=2 |pages=306–315 |doi=10.1670/15-023 |s2cid=88200803 |issn=0022-1511}} However in 2020, a study reconsiders that American alligators Late Miocene record. With the older fossils being reassigned to Alligator mefferdi and Alligator hailensis. With American alligators evolving sometime during the Middle Pleistocene.{{cite journal |last1=Stout |first1=J.B. |date=2020 |title=New early Pleistocene Alligator (Eusuchia: Crocodylia) from Florida bridges a Gap in Alligator evolution |url=https://www.researchgate.net/publication/344844631 |journal=Zootaxa |volume=4868 |issue=1 |pages=41–60 |doi=10.11646/zootaxa.4868.1.3 |pmid=33311408 |s2cid=226337860}}

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.{{cite journal |author1=Janke, A. |author2=Arnason, U. |year=1997 |title=The complete mitochondrial genome of Alligator mississippiensis and the separation between recent archosauria (birds and crocodiles) |journal=Molecular Biology and Evolution |volume=14 |issue=12 |pages=1266–72 |pmid=9402737 |doi=10.1093/oxfordjournals.molbev.a025736 |doi-access=free}} However, the full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds.{{cite journal |vauthors=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 |title=Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs |journal=Science |volume=346 |issue=6215 |page=1254449 |year=2014 |pmid=25504731 |pmc=4386873 |doi=10.1126/science.1254449 }}

File:Alligator Crâne et Mandibule.jpg

File:Alligator mississippiensis 3d scan Natural History Museum University of Pisa B 66.stl

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.

The American alligator is a relatively large species of crocodilian. On average, it is the largest species in the family Alligatoridae, with only the black caiman being possibly larger.Thorbjarnarson, J. B. (2010). Black caiman Melanosuchus niger. Crocodiles. Status Survey and Conservation Action Plan, 29–39. 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 similar-length crocodilians; for example, captive males measuring {{convert|3|to|4|m|ftin|abbr=on}} were found to weigh {{convert|200|to|350|kg|lb|abbr=on}}, although captive specimens may outweigh wild specimens due to lack of hunting behavior and other stressors.{{cite journal|author=Woodward, A. R.|author2=White, J. H.|author3=Linda, S. B.|name-list-style=amp |year=1995|title=Maximum size of the alligator (Alligator mississippiensis)|journal= Journal of Herpetology|pages= 507–513|jstor=1564733|volume=29|issue=4|doi=10.2307/1564733}}{{cite journal | last1 = Clippinger | first1 = T. L. | last2 = Avery Bennett | first2 = R. | last3 = Johnson | first3 = C. M. | last4 = Vliet | first4 = K. A. | last5 = Deem | first5 = S. L. | last6 = Orós | first6 = J. | last7 = Brown | first7 = M. B. | year = 2000 | title = Morbidity and mortality associated with a new mycoplasma species from captive American alligators (Alligator mississippiensis) | journal = Journal of Zoo and Wildlife Medicine | volume = 31 | issue = 3| pages = 303–314 | doi=10.1638/1042-7260(2000)031[0303:mamawa]2.0.co;2| pmid = 11237136 | s2cid = 42676388 }}

Large male American alligators reach an expected maximum size up to {{convert|4.6|m|ftin|abbr=on}} in length and weigh up to {{cvt|500|kg|lb|-2}}, while females reach an expected maximum of {{convert|3|m|ftin|abbr=on}}.[https://web.archive.org/web/20100117092307/http://animals.nationalgeographic.com/animals/reptiles/american-alligator American Alligators, American Alligator Pictures, American Alligator Facts – National Geographic]. Animals.nationalgeographic.com.[http://www.philadelphiazoo.org/Animals/Reptiles/Crocodiles-Alligators/American-Alligator.htm American alligator] {{webarchive |url=https://web.archive.org/web/20130411194955/http://www.philadelphiazoo.org/Animals/Reptiles/Crocodiles-Alligators/American-Alligator.htm |date=April 11, 2013}}. Philadelphia Zoo.{{cite book |title=Reptile biodiversity: standard methods for inventory and monitoring |date=2012 |publisher=University of California press |location=Berkeley (Calif.) |isbn=978-0-520-26671-1 |pages=11 |url=https://books.google.com/books?id=H6m4YEF9MXwC}} However, the largest free-ranging female had a total length of {{Cvt|3.22|m|ftin}} and weighed {{Cvt|170|kg|lb}}.{{cite journal |last1=Deem |first1=Vincent R. |last2=Letter |first2=Andrew W. |last3=Woodward |first3=Allan R. |last4=Ford |first4=Ryan M. |last5=Moore |first5=Brandon C. |title=Maximum Size of Female American Alligators and a New Record Total Length and Weight |journal=Southeastern Naturalist |date=5 February 2021 |volume=20 |issue=1 |doi=10.1656/058.020.0109 |s2cid=232326848 |url=https://bioone.org/journals/southeastern-naturalist/volume-20/issue-1/058.020.0109/Maximum-Size-of-Female-American-Alligators-and-a-New-Record/10.1656/058.020.0109.short}} On rare occasions, a large, old male may grow to an even greater length.Charles, S.; Ross, A. and Garnett, Stephen (1989) Crocodiles and Alligators. Checkmark Books. {{ISBN|978-0-8160-2174-1}}.{{cite book | author = Wood, Gerald | url = https://archive.org/details/guinnessbookofan00wood | title = The Guinness Book of Animal Facts and Feats | year = 1983 | publisher = Guinness Superlatives | isbn = 978-0-85112-235-9 }}

During the 19th and 20th centuries, larger males reaching {{convert|5|to|6|m|ftin|abbr=on}} were reported.{{cite web|url=http://www.flmnh.ufl.edu/cnhc/csp_amis.htm |title=Crocodilian Species—American Alligator (Alligator mississippiensis) |publisher=Flmnh.ufl.edu |access-date=October 14, 2008}} The largest reported individual size was a male killed in 1890 by Edward McIlhennyWoodward, A. R., White, J. H., & Linda, S. B. (1995). Maximum size of the alligator (Alligator mississippiensis). Journal of Herpetology, 507-513. on Marsh Island, Louisiana, and reportedly measured at {{convert|5.84|m|ftin|abbr=on}} 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. If the size of this animal was correct, it would have weighed about {{convert|1000|kg|lb|abbr=on}}.{{cite journal|author=Smith, E. N.|author2=Standora, E. A.|author3=Robertson, S. L.|name-list-style=amp |title=Physiological thermoregulation of mature alligators|journal=Comparative Biochemistry and Physiology. A, Comparative Physiology|volume=77|issue=1|pages=189–93|pmid=6141029|year=1984|doi=10.1016/0300-9629(84)90033-1}} In Arkansas, a man killed an American alligator that was {{convert|4.04|m|ftin|abbr=on}} and {{convert|626|kg|lb|abbr=on}}.{{cite web|url=https://www.foxnews.com/us/record-gator-caught-in-southwest-arkansas/|title=Record gator caught in Southwest Arkansas|publisher=FoxNews.com|access-date=March 15, 2014}} The largest American alligator ever killed in Florida was {{convert|5.31|m|ftin|abbr=on}}, as reported by the Everglades National Park, although this record is unverified.[https://web.archive.org/web/20120205061623/http://www.everglades.national-park.com/bird.htm Everglades National Park Flora & Fauna Page]. Everglades National Park[http://www.floridaadventuring.com/florida-alligator.html Florida alligator] {{Webarchive|url=https://web.archive.org/web/20131230232726/http://www.floridaadventuring.com/florida-alligator.html |date=December 30, 2013 }}. Floridaadventuring.com (March 2, 2016). Retrieved on 2016-09-07. The largest American alligator scientifically verified in Florida for the period from 1977 to 1993 was reportedly {{convert|4.23|m|ftin|abbr=on}} and weighed {{convert|473|kg|lb|abbr=on}}, although another specimen (size estimated from skull) may have measured {{convert|4.54|m|ftin|abbr=on}}. A specimen that was {{convert|4.5|m|ftin|abbr=on}} long and weighed {{convert|458.8|kg|lb|1|abbr=on}} is the largest American alligator killed in Alabama and has been declared the SCI world record in 2014.{{cite journal |last1=Brunell |first1=Arnold M. |last2=Rainwater |first2=Thomas R. |last3=Sievering |first3=Michael |last4=Platt |first4=Steven G. |title=A New Record for the Maximum Length of the American Alligator |journal=Southeastern Naturalist |date=September 2015 |volume=14 |issue=3 |pages=N38–N43 |doi=10.1656/058.014.0302 |s2cid=86247523 |url=https://bioone.org/journals/southeastern-naturalist/volume-14/issue-3/058.014.0302/A-New-Record-for-the-Maximum-Length-of-the-American/10.1656/058.014.0302.short}}{{cite journal |last1=Platt |first1=Steven G. |last2=Elsey |first2=Ruth M. |last3=Rainwater |first3=Thomas R. |last4=Fredenberg |first4=Mike |title=A Critical Analysis of a Historic Size Record for the American Alligator |journal=Southeastern Naturalist |date=1 November 2018 |volume=17 |issue=4 |doi=10.1656/058.017.0403 |s2cid=92148606 |url=https://bioone.org/journals/southeastern-naturalist/volume-17/issue-4/058.017.0403/A-Critical-Analysis-of-a-Historic-Size-Record-for-the/10.1656/058.017.0403.short}}

American alligators do not normally reach such extreme sizes. In mature males, most specimens grow up to about {{convert|3.4|m|ftin|abbr=on}} in length, and weigh up to {{convert|360|kg|lb|abbr=on}},{{cite web|url=http://www.animalspot.net/american-alligator.html|title=American Alligator|website=www.animalspot.net|date=June 16, 2012|language=en-US|access-date=April 24, 2017}} while in females, the mature size is normally around {{convert|2.6|m|ftin|abbr=on}}, with a body weight up to {{convert|91|kg|lb|abbr=on}}.{{cite web |title=Gator factsheet |publisher=Savannah River Ecology Laboratory |url=http://srelherp.uga.edu/SPARC/PDFs/gator-fact-sheetA.pdf |access-date=August 14, 2012 |archive-date=May 12, 2013 |archive-url=https://web.archive.org/web/20130512090737/http://srelherp.uga.edu/SPARC/PDFs/gator-fact-sheetA.pdf |url-status=dead }}{{cite web |url=http://nationalzoo.si.edu/animals/reptilesamphibians/facts/factsheets/americanalligator.cfm |title=American Alligator Fact Sheet |publisher=The National Zoo |access-date=December 30, 2013}} In Newnans Lake, Florida, adult males averaged {{convert|73.2|kg|lb|abbr=on}} in weight and {{convert|2.47|m|ftin|abbr=on}} in length, while adult females averaged {{convert|55.1|kg|lb|abbr=on}} and measured {{convert|2.22|m|ftin|abbr=on}}.{{cite journal|last=Goodwin |first=Thomas M. |year=1979 |title=Seasonal activity ranges and habitat preferences of adult alligators in a north-central Florida lake |journal=Journal of Hepatology |volume=13 |issue=2 |pages=157–64 |jstor=1563922|doi=10.2307/1563922 }} In Lake Griffin State Park, Florida, adults weighed on average {{convert|57.9|kg|lb|abbr=on}}.{{cite journal | last1 = Honeyfield | first1 = D. C. | last2 = Ross | first2 = J. P. | last3 = Carbonneau | first3 = D. A. | last4 = Terrell | first4 = S. P. | last5 = Woodward | first5 = A. R. | last6 = Schoeb | first6 = T. R. | last7 = Hinterkopf | first7 = J. P. | year = 2008 | title = Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis) | journal = Journal of Wildlife Diseases | volume = 44 | issue = 2| pages = 280–294 | doi=10.7589/0090-3558-44.2.280| pmid = 18436661 | doi-access = free }} Weight at sexual maturity per one study was stated as averaging {{convert|30|kg|lb|abbr=on}} while adult weight was claimed as {{convert|160|kg|lb|abbr=on}}.{{cite journal | last1 = Ruben | first1 = J. A. | last2 = Jones | first2 = T. D. | year = 2000 | title = Selective factors associated with the origin of fur and feathers | journal = American Zoologist | volume = 40 | issue = 4| pages = 585–596 | doi=10.1668/0003-1569(2000)040[0585:sfawto]2.0.co;2| s2cid = 55795562 }}

There is a common presumption stated throughout reptilian literature that crocodilians, including the American alligator, exhibit indeterminate growth, meaning the animal continues to grow for the duration of its life. However, these claims are largely based on assumptions and observations of juvenile and young adult crocodilians, and recent studies are beginning to contradict this claim. For example, one long-term mark-recapture study (1979–2015) done at the Tom Yawkey Wildlife Center in South Carolina found evidence to support patterns of determinate growth, with growth ceasing upon reaching a certain age (43 years for males and 31 years for females).{{Cite journal |last1=Wilkinson |first1=Philip M. |last2=Rainwater |first2=Thomas R. |last3=Woodward |first3=Allan R. |last4=Leone |first4=Erin H. |last5=Carter |first5=Cameron |date=November 2016 |title=Determinate Growth and Reproductive Lifespan in the American Alligator (Alligator mississippiensis): Evidence from Long-term Recaptures |url=https://bioone.org/journals/copeia/volume-104/issue-4/CH-16-430/Determinate-Growth-and-Reproductive-Lifespan-in-the-American-Alligator-Alligator/10.1643/CH-16-430.full |journal=Copeia |volume=104 |issue=4 |pages=843–852 |doi=10.1643/CH-16-430 |s2cid=89048080 |issn=0045-8511}}

While noticeable in very mature specimens, the sexual dimorphism in size of the American alligator is relatively modest among crocodilians.{{cite journal | last1 = Saalfeld | first1 = D. T. | last2 = Webb | first2 = K. K. | last3 = Conway | first3 = W. C. | last4 = Calkins | first4 = G. E. | last5 = Duguay | first5 = J. P. | year = 2008 | title = Growth and condition of American alligators (Alligator mississippiensis) in an inland wetland of east Texas | journal = Southeastern Naturalist | volume = 7 | issue = 3| pages = 541–550 | doi=10.1656/1528-7092-7.3.541| s2cid = 84645749 }} For contrast, the sexual dimorphism of saltwater crocodiles is much more extreme, with mature males nearly twice as long as and at least four times as heavy as female saltwater crocodiles.{{cite journal | last1 = Webb | first1 = GJW. | last2 = Messel | first2 = H. | s2cid = 56360888 | year = 1978 | title = Morphometric analysis of Crocodylus porosus from the north coast of Arnhem Land, northern Australia | doi = 10.1071/zo9780001 | journal = Australian Journal of Zoology | volume = 26 | issue = 1| pages = 1–27 }} Given that female American alligators have relatively higher survival rates at an early age and a large percentage of given populations consists of immature or young breeding American alligators, relatively few large mature males of the expected mature length of {{convert|3.4|m|ftin|abbr=on}} or more are typically seen.{{cite journal | last1 = Lance | first1 = V. A. | last2 = Elsey | first2 = R. M. | last3 = Lang | first3 = J. W. | year = 2000 | title = Sex ratios of American alligators (Crocodylidae): male or female biased? | journal = Journal of Zoology | volume = 252 | issue = 1| pages = 71–78 | doi=10.1017/s0952836900009080}}

Dorsally, adult American alligators may be olive, brown, gray, or black. However, they are on average one of the most darkly colored modern crocodilians (although other alligatorid family members are also fairly dark), and can reliably be distinguished by color via their more blackish dorsal scales against crocodiles. Meanwhile, their undersides are cream-colored.{{cite web|title=American Alligator: Species Profile|publisher=US National Park Service|access-date=August 14, 2012|url=http://www.nps.gov/ever/naturescience/alligator.htm}} Some American alligators are missing or have 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.{{cite web|url=https://www.nbcnews.com/id/wbna18620211|title=Zoo keeps albino alligator in the dark |publisher=NBC News.com |date=May 11, 2007 |access-date=August 15, 2012}}

File:AmericanAlligator3.jpg

File:American alligator (Alligator mississippiensis) skull nostrils at the Royal Veterinary College anatomy museum.JPG

American alligators have 74–80 teeth. As they grow and develop, the morphology of their teeth and jaws change significantly.{{Cite journal|last1=Erickson|first1=Gregory M.|last2=Lappin|first2=A. Kristopher|last3=Vliet|first3=Kent A.|s2cid=241524|date=March 2003|title=The ontogeny of bite-force performance in American alligator (Alligator mississippiensis)|journal=Journal of Zoology|volume=260|issue=3|pages=317–327|doi=10.1017/s0952836903003819|issn=0952-8369}} Ventral pterygoideus muscles are enlarged and extremely powerful.{{Cite journal |last=Gignac |first=P. M. |last2=Erickson |first2=G. M. |date=2016 |title=Ontogenetic bite-force modeling of Alligator mississippiensis: implications for dietary transitions in a large-bodied vertebrate and the evolution of crocodylian feeding |url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/jzo.12349 |journal=Journal of Zoology |language=en |volume=299 |issue=4 |pages=229–238 |doi=10.1111/jzo.12349 |issn=1469-7998}} Juveniles have small, needle-like teeth that become much more robust and narrow snouts that become broader as the individuals develop. These morphological changes correspond to shifts in the American alligators' diets, from smaller prey items such as fish and insects to larger prey items such as turtles, birds, and other large vertebrates. 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. American alligators are often mistaken for a similar animal: the American crocodile. An easy characteristic to distinguish the two is the fourth tooth. Whenever an American alligator's mouth is closed, the fourth tooth is no longer visible. It is enclosed in a pocket in the upper jaw. Alligators also frequently lose and replace their teeth, about once every year. {{cite journal |last1=Wu |first1=Ping |last2=Wu |first2=Xiaoshan |last3=Jiang |first3=Ting-Xin |last4=M. Elsey |first4=Ruth |last5=L. Temple |first5=Bradley |last6=J. Divers |first6=Stephen |last7=C. Glenn |first7=Travis |last8=Yuan |first8=Kuo |last9=Chen |first9=Min-Huey |last10=B. Widelitz |first10=Randall |last11=Chuong |first11=Cheng-Ming |title=Specialized stem cell niche enables repetitive renewal of alligator teeth |journal=PNAS |date=13 May 2013 |pages=10 |url=https://www.pnas.org/doi/abs/10.1073/pnas.1213202110 |access-date=19 February 2025}} As alligators live a lengthy life, they can go through over 2,000 teeth in their lifetimes.{{cite web |title=AnimalHub: Discover fascinating facts about American Alligator |url=https://animalhub.earth/animals/american-alligator/fascinating-facts |website=AnimalHub |access-date=19 February 2025}}

Adult American alligators held the record as having the strongest laboratory-measured bite of any living animal, measured at up to {{convert|13172|N|kgf lbf|abbr=on|lk=on}}. 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 {{convert|16414|N|kgf lbf|abbr=on}} in saltwater crocodiles;{{cite journal |title=Comparison of bite-force performance between long-term captive and wild American alligators (Alligator mississippiensis) |journal=Journal of Zoology |volume=262 |issue=1 |pages=21–28 |url=http://www.alligatorfarm.us/images/Research/Erickson%20et%20al.%202004.pdf|doi=10.1017/S0952836903004400 |year=2004 |last1=Erickson |first1=Gregory M. |last2=Lappin |first2=A. Kristopher |last3=Parker |first3= Trevor |last4=Vliet |first4=Kent A.}}{{cite journal|last=Erickson|first=GM|author2=Gignac PM |author3=Steppan SJ |author4=Lappin AK |author5=Vliet KA |year=2012|title=Insights into the Ecology and Evolutionary Success of Crocodilians Revealed through Bite-Force and Tooth-Pressure Experimentation|journal=PLOS ONE|volume=7|issue=3|pages=e31781|doi=10.1371/journal.pone.0031781|pmid=22431965|pmc=3303775|display-authors=etal|bibcode=2012PLoSO...731781E|doi-access=free}} 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. No significant difference is noted between the bite forces of male and female American alligators of equal size. Another study noted that as the American alligator increases in size, the force of its bite also increases.Erickson, G. M., Lappin, A. K., & Vliet, K. A. (2003). The ontogeny of bite-force performance in American alligator (Alligator mississippiensis). Journal of Zoology, 260(3), 317–327

File:AmericanAlligator77.JPG

File:X-ray video of a female American alligator (Alligator mississippiensis) while breathing - pone.0004497.s009.ogv 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.{{cite journal|last1=Reilly |first1=S. M. |last2=Elias |first2=J. A. |year=1998 |title=Locomotion in alligator mississippiensis: kinematic effects of speed and posture and their relevance to the sprawling-to-erect paradigm |journal=The Journal of Experimental Biology |volume=201 |issue=18 |pages=2559–74 |doi=10.1242/jeb.201.18.2559 |pmid=9716509 |url=http://jeb.biologists.org/content/201/18/2559.full.pdf |doi-access=free |bibcode=1998JExpB.201.2559R }}

In the water, American alligators swim like fish, moving their pelvic regions and tails from side to side.{{cite journal |last=Fish |first=F. E. |year=1984 |title=Kinematics of undulatory swimming in the American alligator |journal=Copeia |pages=839–43 |url=http://darwin.wcupa.edu/~biology/fish/pubs/pdf/1984CopeiaKinematics.pdf |doi=10.2307/1445326 |volume=1984 |issue=4 |jstor=1445326 |url-status=dead |archive-url=https://web.archive.org/web/20131021220152/http://darwin.wcupa.edu/~biology/fish/pubs/pdf/1984CopeiaKinematics.pdf |archive-date=October 21, 2013 |df=mdy-all}} Swimming is assisted by webbed rear feet as well, which bear four toes in contrast to the five toes of the front feet.{{cite web|url=https://www.fws.gov/species/american-alligator-alligator-mississippiensis|title=American Alligator|website=U.S. Fish & Wildlife Service|access-date=1 September 2024}}{{cite web|url=https://www.nwf.org/Educational-Resources/Wildlife-Guide/Reptiles/American-Alligator|title=American Alligator|website=National Wildlife Federation|access-date=1 September 2024}} During respiration, air flow is unidirectional, looping through the lungs during inhalation and exhalation;{{Cite journal |last1=Farmer |first1=C. G. |last2=Sanders |first2=K. |s2cid=206522844 |year=2010 |title=Unidirectional airflow in the lungs of American alligators |journal=Science |volume=327 |issue=5963 |pages=338–340 |doi=10.1126/science.1180219 |pmid=20075253|bibcode=2010Sci...327..338F }} 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.{{cite journal |title=Recruitment of the diaphragmaticus, ischiopubis and other respiratory muscles to control pitch and roll in the American alligator (Alligator mississippiensis) |journal=Journal of Experimental Biology |volume=211 |issue=7 |pages=1141–11477 |doi=10.1242/jeb.015339 |year=2008 |last1=Uriona |first1=T. J. |last2=Farmer |first2= C. G. |pmid=18344489|doi-access=free |bibcode=2008JExpB.211.1141U }}

File:Crocodile and Gator at Mrazek Pond (2), EVER, NPSPhoto, SCotrell, 4-2011 (9255694189).jpg (left) at Mrazek Pond, Florida]]

American alligators, being native both to the Nearctic and Neotropical realms, are found in the wild in the Southeastern United States, from the Lowcountry in South Carolina, south to Everglades National Park in Florida, and west to the southeastern region of Texas.{{cite web|last=Sigler|first=Luis|date=September 2007|title=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.|url=https://www.researchgate.net/publication/305721061|access-date=May 12, 2018}} They are found in parts of North Carolina, South Carolina, Georgia, Florida, Louisiana, Alabama, Mississippi, Arkansas, Oklahoma, and Texas. Some of these locations appear to be relatively recent introductions, with often small but reproductive populations.{{cite web|url=https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=221 |title=NAS - Nonindigenous Aquatic Species: Alligator mississippiensis|website=USGS}} Louisiana has the largest American alligator population of any U.S. state. In the future, possible American alligator populations may be found in areas of Mexico adjacent to the Texas border.{{cite web|url=https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=221 |title=American alligator (Alligator mississippiensis) - Species Profile |publisher=Nas.er.usgs.gov |date= |accessdate=2022-03-16}} The range of the American alligator is slowly expanding northwards, including into areas they once found such as Virginia.{{Cite web |date=2023-12-19 |title=Why We Almost Said "See You Later" to the American Alligator {{!}} Defenders of Wildlife |url=https://defenders.org/blog/2023/12/why-we-almost-said-see-you-later-american-alligator |access-date=2024-08-03 |website=defenders.org |language=en}} American alligators have been naturally expanding their range into Tennessee,{{Cite web |title=Alligators have been sighted in Tennessee |url=https://www.tn.gov/twra/wildlife/reptiles/alligators.html |access-date=2022-08-02 |website=www.tn.gov |language=en}} and have established a small population in the southwestern part of that state via inland waterways, according to the state's wildlife agency.{{Cite web |last=Outdoors |first=Grand View |date=2019-07-02 |title=Alligators Expanding Range, Confirmed in… |url=https://www.grandviewoutdoors.com/news/alligators-expanding-range-confirmed-in-tennessee |access-date=2022-08-02 |website=Grand View Outdoors |language=en}} They have been extirpated from Virginia, and occasional vagrants from North Carolina wander into the Great Dismal Swamp.{{cite web |author=VLM Staff |date=April 30, 2016 |title=Herp Highlight #1: American Alligator |url=https://thevlm.org/herp-highlight-1-american-alligator/ |access-date=April 8, 2021 |work=TheVLM.org |publisher=Virginia Living Museum (VLM)}}

In 2021, an individual was found in Calvert County, Maryland, near Chesapeake Bay, where it was shot and killed by a hunter using a crossbow. Additional reports of American alligators from this region exist, though they are believed to be escaped or released exotic pets.{{Cite web |last=Bulletin |first=Bay |date=2021-06-22 |title=Calvert Man Recounts How He Caught 7.5-Foot Alligator from Chesapeake Bay |url=https://www.chesapeakebaymagazine.com/calvert-co-man-claims-7-5-foot-alligator-caught-from-chesapeake-bay/ |access-date=2024-08-03 |website=Chesapeake Bay Magazine |language=en-US}}

File:LeucisticAlligator.jpg American alligator at Gatorland]]

American alligators are currently listed as least concern by the IUCN Red List, even though from the 1800s to the mid-1900s, they were being hunted and poached by humans unsustainably.

Historically, hunting and habitat loss have severely affected 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 to the Endangered Species Act of 1973), since it was believed to be in danger of extinction throughout all or a significant portion of its range.{{cite web|date=February 2008|title=American Alligator Alligator mississippiensis|url=http://www.fws.gov/endangered/esa-library/pdf/alligator.pdf|url-status=dead|archive-url=https://web.archive.org/web/20200702034410/https://www.fws.gov/endangered/esa-library/pdf/alligator.pdf|archive-date=2 July 2020|publisher=U.S. Fish and Wildlife Service}}

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.[https://www.captainjacksairboattours.com/7-are-alligators-endangered/ captain jacks air boat tours] Retrieved June 26, 2020. 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.

American alligators are listed under Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning that international trade in the species (including parts and derivatives) is regulated.

File:Alligatoridae - Alligator mississippiensis from Everglades.webmThey inhabit swamps, streams, rivers, ponds, and lakes as well as wetland prairies interspersed with shallow open water and canals with associated levees.{{Cite journal |last1=WEBB |first1=KEVIN K. |last2=CONWAY |first2=WARREN C. |last3=CALKINS |first3=GARY E. |last4=DUGUAY |first4=JEFFREY P. |date=May 2009 |title=Habitat Use of American Alligators in East Texas |url=http://dx.doi.org/10.2193/2006-294 |journal=The Journal of Wildlife Management |volume=73 |issue=4 |pages=566–572 |doi=10.2193/2006-294 |issn=0022-541X}} A lone American alligator was spotted for over 10 years living in a river north of Atlanta, Georgia.{{Cite news|url=http://www.myajc.com/news/hooch-gator-trapped/Dty4FQvuIqEEc2IhC9yqTI/|title=Elusive Chattahoochee alligator caught in Cobb County|newspaper=myajc|access-date=December 17, 2016}} 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,{{cite web|title=American Alligator (Alligator mississippiensis)|publisher=Savannah River Ecology Lab|access-date=August 16, 2012|url=http://srelherp.uga.edu/alligators/allmis.htm|archive-date=March 28, 2023|archive-url=https://web.archive.org/web/20230328011456/http://srelherp.uga.edu/alligators/allmis.htm|url-status=dead}} but are less tolerant of salt water than American crocodiles, as the salt glands on their tongues do not function.{{cite web|title=What's the difference between a crocodile and an alligator?|publisher=Flmnh.ufl.edu.|access-date=August 26, 2012|url=http://crocodilian.com/cnhc/cbd-faq-q1.htm|archive-date=October 11, 2012|archive-url=https://web.archive.org/web/20121011223513/http://crocodilian.com/cnhc/cbd-faq-q1.htm|url-status=dead}} One study of American 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.

In some areas of their range, American alligators are an unusual example of urban wildlife; golf courses are often favored by the species due to an abundance of water and a frequent supply of prey animals such as fish and birds.{{cite web|date=2015-03-12|title=Alligator hazard is par for the course at Florida golf club|url=http://www.theguardian.com/us-news/2015/mar/12/alligator-florida-golf-club-par-for-the-course|access-date=2022-01-20|website=The Guardian|language=en}}{{cite news|date=2020-11-12|title=Enormous alligator spotted on Florida golf course|url=https://www.independent.co.uk/news/world/americas/alligator-florida-naples-golf-course-b1721855.html |archive-url=https://web.archive.org/web/20201113070828/https://www.independent.co.uk/news/world/americas/alligator-florida-naples-golf-course-b1721855.html |archive-date=2020-11-13 |url-access=limited |url-status=live|access-date=2022-01-20|website=The Independent|language=en}}

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 {{convert|45|F|C}} or less, an American alligator can survive in such temperatures for some time without displaying any signs of discomfort.{{cite book | author = Guggisberg, C.A.W. | title = Crocodiles: Their Natural History, Folklore, and Conservation| year = 1972 | page = 195 | isbn = 978-0-7153-5272-4 | publisher = David & Charles | location = Newton Abbot}} This adaptiveness is thought to be why American alligators are widespread further north than the American crocodile. In fact, the American alligator is found farther from the equator and is more equipped to handle cooler conditions than any other crocodilian.{{cite journal |title=Alligator physiology and life history: the importance of temperature |first=Valentine A. |last=Lance |journal=Experimental Gerontology |volume=38 |issue=7 |year=2003 |pages=801–805 |doi=10.1016/S0531-5565(03)00112-8 |pmid=12855291 |s2cid=31045078 }} 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, and they can remain in this state for several days.{{cite web|last=Bryner |first=Jeanna |title=How Alligators Survive in a Frozen Pond: They 'Snorkel'|url=https://www.livescience.com/64592-alligators-weird-snout-behavior-winter.html|access-date=2020-08-15|website=livescience.com|date=January 25, 2019 |language=en}}

File:Alligator mississippiensis (American alligator) 6.jpg.]]

American alligators primarily bask on shore, but also climb into and perch on tree limbs to bask if no shoreline is available. This is not often seen, since if disturbed, they quickly retreat back into the water by jumping from their perch.{{Cite journal|url=http://www.herpetologynotes.seh-herpetology.org/Volume7_PDFs/Dinets_HerpetologyNotes_volume7_pages3-7.pdf|title=Climbing behaviour in extant crocodilians |last1=Dinets |first1=Vladimir |last2=Britton |first2=Adam |last3=Shirley |first3=Matthew |year=2013 |journal=Herpetology Notes |volume=7 |pages=3–7}} (published online January 25, 2014)

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, which survive the dry season by seeking refuge in alligator holes, so 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, provides 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.{{cite web |last1=Rice |first1=Ken G. |last2=Mazzotti |first2=Frank |title=American Alligator Ecology and Monitoring for the Comprehensive Everglades Restoration Plan |date=October 2005 |url=http://edis.ifas.ufl.edu/pdffiles/UW/UW23200.pdf |publisher=University of Florida IFAS Extension}} 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.{{cite journal|last1=Campell |first1=Mark R. |last2=Mazzotti |first2=Frank J. |year=2004 |title=Characterization of Natural and Artificial Alligator Holes |journal=Southeastern Naturalist |volume=3 |issue=4 |pages=583–94 |doi=10.1656/1528-7092(2004)003[0583:CONAAA]2.0.CO;2 |jstor=3878020 |s2cid=85653669 }}

File:American Alligator, Laguna Atascosa NWR, TX imported from iNaturalist photo 3908367.jpg|Baby eating a southern leopard frog

File:Gator with bullfrog at Lake Woodruff - Flickr - Andrea Westmoreland.jpg|Young alligator eating a bullfrog

File:Alligator feeding on worm.jpg|Young alligator eating worms

File:American Alligator, Chambers County, TX, USA imported from iNaturalist photo 303450133.jpg|Eating a Florida gar

File:See You Later, Alligator . ..jpg|Eating a pleco

File:American Alligator eating Blue Crab 2.JPG|Eating a swimmer crab

File:American Alligator, Gulf State Park, Gulf Shores, AL, US imported from iNaturalist photo 58085636.jpg|Eating a redhead duck

File:American Alligator, Big Cypress National Preserve, Ochopee, FL, US imported from iNaturalist photo 345267533.jpg|Eating a great blue heron

File:Ker'CHOMP - Flickr - Andrea Westmoreland.jpg|Eating a Florida softshell turtle

File:Alligator consuming turtle2.jpg|Eating a cooter

File:American Alligator, Vacherie, LA 70090, USA imported from iNaturalist photo 4747597.jpg|Eating a nutria

File:American Alligator, Brazoria County, TX, USA imported from iNaturalist photo 283873098.jpg|Eating a feral pig

File:Gator and Python.jpg|Killing an invasive Burmese python, which is attempting to coil around it

File:Gator-with-deer2.jpg|With deer

The teeth of the American alligator are designed to grip prey, but cannot 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 attainment of adulthood enables the consumption of large mammals and the crushing of large turtles.{{Cite journal |last1=Erickson |first1=Gregory M. |last2=Lappin |first2=A. Kristopher |last3=Vliet |first3=Kent A. |date=July 2003 |title=The ontogeny of bite-force performance in American alligator (Alligator mississippiensis) |url=http://dx.doi.org/10.1017/s0952836903003819 |journal=Journal of Zoology |volume=260 |issue=3 |pages=317–327 |doi=10.1017/s0952836903003819 |issn=0952-8369}} The American alligator is capable of biting through a turtle's shell or a moderately sized mammal bone.[http://edis.ifas.ufl.edu/uw230 WEC203/UW230: Living with Alligators: A Florida Reality]. Edis.ifas.ufl.edu. Retrieved on August 21, 2012. Additionally, the palate of American alligators enables them to capture prey underwater without flooding their respiratory system with water{{Cite journal |last=Ferguson |first=M. W. J. |date=1981-01-01 |title=The structure and development of the palate in Alligator mississippiensis |url=https://linkinghub.elsevier.com/retrieve/pii/0003996981900418 |journal=Archives of Oral Biology |volume=26 |issue=5 |pages=427–443 |doi=10.1016/0003-9969(81)90041-8 |issn=0003-9969}}

American alligators have been documented using lures to hunt prey such as birds.{{cite journal|first1=V|last1=Dinets|first2=JC|last2=Brueggen|first3=J.D.|last3=Brueggen |title=Crocodilians use tools for hunting|journal=Ethology, Ecology and Evolution |year=2014 |volume=27 |doi=10.1080/03949370.2013.858276 |pages=74–78 |s2cid=84655220}} 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.{{cite web|url=https://www.sciencedaily.com/releases/2013/12/131204182433.htm|title=Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey|website=ScienceDaily|date=December 4, 2013|access-date=December 8, 2013}} This strategy has been documented in two Florida zoos occurring multiple times a day in peak nesting season and in some parks in Louisiana. The use of tools was documented primarily during the peak rookery season when birds were primarily looking for sticks.

However, a three-day experiment to reproduce the use of sticks as lures, published in 2019, failed to document the behavior. Researchers placed sticks at densities of 30 to 35 sticks per meter squared near four captive populations, two near rookeries and two at no-rookery sites. While stick-displaying behavior was observed several times, it was not more frequent near rookeries. In fact, in some comparisons, it was associated with no-rookery sites. This implies American alligators do not tailor this behavior to specific contexts, leaving the purpose, if any, of stick-displaying ambiguous.{{Cite journal |last1=Rosenblatt |first1=Adam E. |last2=Johnson |first2=Alyssa |date=2019-11-26 |title=An experimental test of crocodilian stick-displaying behavior |url=https://www.tandfonline.com/doi/full/10.1080/03949370.2019.1691057 |journal=Ethology Ecology & Evolution |language=en |volume=32 |issue=3 |pages=218–226 |doi=10.1080/03949370.2019.1691057 |issn=0394-9370}}

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 {{convert|50|m|ft|order=flip}} from water, ambushing terrestrial animals on trailsides and road shoulders. Usually, terrestrial hunting occurs on nights with warm temperatures.{{cite journal |last=Dinets |first=V. L. |year=2011 |title=On terrestrial hunting in crocodilians |volume=114 |journal=Herpetological Bulletin |pages=15–18 |url=http://dinets.travel.ru/Pages%20from%20Bulletin%20114%20Dinets.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111015150803/http://dinets.travel.ru/Pages%20from%20Bulletin%20114%20Dinets.pdf |archive-date=October 15, 2011 |df=mdy-all}} 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.

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 that encounters between the two predators are common.{{cite news|url=http://news.nationalgeographic.com/2017/09/american-alligator-sharks-predators-stingrays/|archive-url=https://web.archive.org/web/20170920232103/http://news.nationalgeographic.com/2017/09/american-alligator-sharks-predators-stingrays/|url-status=dead|archive-date=September 20, 2017|title=Alligators Attack and Eat Sharks, Study Confirms|author=Jason Bittel|date=September 20, 2017|newspaper=National Geographic}}{{cite journal|title=Reciprocal Intraguild Predation between Alligator mississippiensis (American Alligator) and Elasmobranchii in the Southeastern United States|journal=Southeastern Naturalist|volume=16|issue=3|year=2017|pages=383–396|first1=James C.|last1=Nifong|first2=Russell H.|last2=Lowers|doi=10.1656/058.016.0306|s2cid=90288005}}

American alligators are considered an apex predator throughout their range. They are opportunists and their diet is determined largely by both their size and age and the size and availability of prey. Most American alligators 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 well as small fish and frogs.{{cite web | url=https://animaldiversity.org/accounts/Alligator_mississippiensis/ | title=Alligator mississippiensis (Alligator, Gator, American alligator, Florida alligator, Mississippi alligator, Louisiana alligator.) | website=Animal Diversity Web }}{{cite web | url=https://crocodilian.com/cnhc/csp_amis.htm | title=Crocodilian Species - American Alligator (Alligator mississippiensis) }} 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 itself. A few examples of animals consumed are largemouth bass, spotted gar, freshwater pearl mussels, American green tree frogs, yellow mud turtles, cottonmouths, common moorhens, and feral wild boars. Stomach contents show, among native mammals, muskrats and raccoons are some of the most commonly eaten species.{{cite journal | last1 = Valentine | first1 = J. M. Jr. | last2 = Walther | first2 = J. R. | last3 = McCartney | first3 = K. M. | last4 = Ivy | first4 = L. M. | year = 1972 | title = Alligator diets on the Sabine National Wildlife Refuge, Louisiana | journal = The Journal of Wildlife Management | volume = 36| issue = 3| pages = 809–815 | doi=10.2307/3799434| jstor = 3799434 }} In Louisiana, where introduced nutria are common, they are perhaps the most regular prey for adult American alligators, although only larger adults commonly eat this species. It has also been reported that large American alligators prey on medium-sized American alligators, which had preyed on hatchlings and smaller juveniles.Rootes, W. L., & Chabreck, R. H. (1993). Cannibalism in the American alligator. Herpetologica, 99–107

If an American alligator's primary food resource is not available, it will sometimes feed on carrion and non-prey items such as rocks and artificial objects, like bottle caps. These items help the American alligator in the process of digestion by crushing up the meat and bones of animals, especially animals with shells.

Other animals may occasionally be eaten, even large deer or feral wild boars, but these are not normally part of the diet. American alligators occasionally prey on large mammals, but usually do so when fish and smaller prey levels go down.{{cite web|title=American Alligator|url=https://www.sciencedaily.com/articles/a/american_alligator.htm|publisher=News Daily|access-date=February 28, 2018|archive-url=https://web.archive.org/web/20150318173004/http://www.sciencedaily.com/articles/a/american_alligator.htm|archive-date=March 18, 2015|url-status=dead}} Rarely, American alligators have been observed killing and eating bobcats, but such events are not common and have little effect on bobcat populations.{{cite web|title=Gator eats bobcat|url=https://www.flickr.com/photos/feltonphoto/8164136944/|publisher=Flickr|access-date=November 7, 2012|date=2012-11-07}}{{cite web|title=Sneaky alligator nearly eats bobcat |url=http://www.kens5.com/video/featured-videos/Sneaky-alligator-nearly-eats-bobcat--156459515.html |publisher=Kens5 |access-date=June 1, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20140111043956/http://www.kens5.com/video/featured-videos/Sneaky-alligator-nearly-eats-bobcat--156459515.html |archive-date=January 11, 2014 }} Although American alligators have been listed as predators of the Nilgai and the West Indian manatees, very little evidence exists of such predation.Whitaker, John O. (1996). The Audubon Society Field Guide to North American Mammals. New York, pg. 808. {{ISBN|978-0-679-44631-6}}. In the 2000s, when invasive Burmese pythons first occupied the Everglades, American alligators have been recorded preying on sizable snakes, possibly controlling populations and preventing the invasive species from spreading northwards.{{cite journal | last1 = Dorcas | first1 = M. E. | last2 = Willson | first2 = J. D. | last3 = Reed | first3 = R. N. | last4 = Snow | first4 = R. W. | last5 = Rochford | first5 = M. R. | last6 = Miller | first6 = M. A. | last7 = Hart | first7 = K. M. | year = 2012 | title = Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park | journal = Proceedings of the National Academy of Sciences | volume = 109 | issue = 7| pages = 2418–2422 | doi=10.1073/pnas.1115226109 | pmid=22308381 | pmc=3289325 | bibcode = 2012PNAS..109.2418D| doi-access = free }} However, the python is also known to occasionally prey on alligators, a form of both competition and predation.{{cite journal | last1 = Nolen | first1 = R. S. | year = 2012 | title = How big is Florida's python problem? | journal = J Am Vet Med Assoc | volume = 240 | issue = 7| pages = 778–782 | pmid = 22443430 | doi = 10.2460/javma.240.7.778 }} 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.Sivlerstein, Alvin (1997). The Florida Panther. Brooksville, Connecticut: Millbrook Press. pp. 41+. {{ISBN|0-7613-0049-X}}. American alligator predation on American black bears has also been recorded.{{cite web|url=http://animallist.weebly.com/american-alligator.html|title=American Alligator|publisher=Animal List}}{{cite web|url=http://www.aquaticcommunity.com/alligators/|title=Alligators|publisher=Aquatic Community}}{{cite web|url=http://www.keywestaquarium.com/alligator|title=Key West Florida Attractions {{!}} Alligator Exhibit|publisher=Key West Aquarium|access-date=December 20, 2012}}

Occasionally, domestic animals, including dogs, cats, and calves, are taken as available, but are secondary to wild and feral prey. Other prey, including snakes, lizards, and various invertebrates, are eaten occasionally by adults.

Water birds, such as herons, 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 occurs with unsteady fledgling birds in late summer, as fledgling birds attempt to make their first flights near the water's edge.

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In 2013, American alligators and other crocodilians were reported to also eat fruit.{{cite web |last=Choi |first=Charles Q. |date=August 30, 2013 |title=Crocodiles and alligators like to chomp down on ... fruit ! |publisher=NBC News: Science |url=http://www.nbcnews.com/science/crocodiles-alligators-chomp-down-fruit-8C11044419 |access-date=August 31, 2013}} 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. Thirty-four families and 46 genera of plants were represented among seeds and fruits found in the stomach contents of American alligators.{{cite journal |last1=Platt |first1=S. G. |last2=Elsey |first2=R. M. |last3=Liu |first3=H. |last4=Rainwater |first4=T. R. |last5=Nifong |first5=J. C. |last6=Rosenblatt |first6=A. E. |last7=Heithaus |first7=M. R. |last8=Mazzotti |first8=F. J. |title=Frugivory and seed dispersal by crocodilians: an overlooked form of saurochory? |journal=Journal of Zoology |date=2013 |volume=291 |issue=2 |pages=87–99 |doi=10.1111/jzo.12052 |doi-access=free}} The discovery of this unexpected part of the American alligator diet further reveals that they may be responsible for spreading seeds from the fruit they consume across their habitat.

Additionally, American alligators engage in what seems to be cooperative hunting.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){{cite journal|first1=Vladmir|last1=Dinets|title=Apparent coordination and collaboration in cooperatively hunting crocodilians|journal=Ethology Ecology & Evolution|year=2014|volume=27|issue=2|pages=244–250|doi=10.1080/03949370.2014.915432|s2cid=84672219}} One observation of cooperative hunting techniques was where there are pushing American alligators and catching American alligators and they were observed taking turns in each position. Another observation said that about 60 American alligators gathered in an area and would form a semicircle with about half of them and would push the fish closer to the bank. Once one of the American alligators caught a fish another one would enter into its spot, and it would take the fish to the resting area. This was reported to have occurred two days in a row.

The diet of adult American alligators from central Florida lakes is dominated by fish, but the species is highly opportunistic 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; 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 nonpiscivore prey, mostly turtles and water snakes.Rice, A. N. (2004). Diet and condition of American alligators (Alligator mississippiensis) in three central Florida lakes (Doctoral dissertation, University of Florida). In southern Louisiana, crustaceans (largely crawfish and crabs) were found to be present in the southeastern American alligators, but largely absent in southwestern American alligators, which consumed a relatively high proportion of reptiles, although fish were the most recorded prey for adults, and adult males consumed a large portion of mammals.{{cite journal | last1 = Gabrey | first1 = S. W. | year = 2010 | title = Demographic and geographic variation in food habits of American alligators (Alligator mississippiensis) in Louisiana | url = http://www.herpconbio.org/Volume_5/Issue_2/Gabrey_2010.pdf| journal = Herpetological Conservation and Biology | volume = 5 | issue = 2| pages = 241–250 }}

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.{{cite journal | last1 = Saalfeld | first1 = D. T. | last2 = Conway | first2 = W. C. | last3 = Calkins | first3 = G. E. | year = 2011 | title = Food Habits of American Alligators (Alligator mississippiensis) in East Texas | journal = Southeastern Naturalist | volume = 10 | issue = 4| pages = 659–672 | doi=10.1656/058.010.0406| s2cid = 85181112 }}

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An American alligator is able to abduct and adduct the vocal folds of its larynx, but not to elongate or shorten them; yet in spite of this, it can modulate fundamental frequency very well.{{Cite journal|title=Subglottal pressure and fundamental frequency control in contact calls of juvenile Alligator mississippiensis |doi-access=free |journal=Journal of Experimental Biology|volume=214|issue=Pt 18|pages=3082–95|pmid=21865521|pmc=3160820|year=2011|last1=Riede|first1=T|last2=Tokuda|first2=I. T.|last3=Farmer|first3=C. G.|doi=10.1242/jeb.051110|bibcode=2011JExpB.214.3082R |url=http://epubs.utah.edu/index.php/open/article/download/775/580}} Their vocal folds consists of epithelium, lamina propria and muscle. Sounds ranged from 50 to 1200 Hz. In one experiment conducted on the larynx, the fundamental frequency depended on both the glottal gap and stiffness of the larynx tissues. As the frequency increases, there's high tension and large strains. The fundamental frequency has been influenced by the glottal gap size and subglottal pressure and when the phonation threshold pressure has been exceeded, there will be vocal fold vibration.{{cite journal |last1=Riede |first1=T |last2=Li |first2=Z |last3=Tokuda |first3=I |last4=Farmer |first4=C |title=Functional morphology of the Alligator mississippiensis larynx with implications for vocal production |journal=Journal of Experimental Biology |date=2015 |volume=218 |issue=7 |pages=991–998 |doi=10.1242/jeb.117101|pmid=25657203 |doi-access=free |bibcode=2015JExpB.218..991R }}

Crocodilians are the most vocal of all non-avian reptiles and have a variety of different calls depending on the age, size, and sex of the animal.{{cite web|last=Britton|first=Adam|title=Crocodile Talk|url=http://crocodilian.com/cnhc/croccomm.html|publisher=University of Bristol and Florida Museum of Natural History |website=Crocodilians |url-status=dead |archive-url=https://web.archive.org/web/20221026132628/http://crocodilian.com/cnhc/croccomm.html |archive-date= Oct 26, 2022 }} The American alligator can perform specific vocalizations to declare territory, signal distress, threaten competitors, and locate suitable mates. Juveniles can perform a high-pitched hatchling call (a "yelping" trait common to many crocodilian species' hatchling young){{cite web |url=https://www.youtube.com/watch?v=ZjqajHt6CAU |title=Hatchling American Alligators Calling |website=YouTube |date=September 3, 2013 |access-date=2016-09-07 |first1=David |last1=Barkasy }} 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.

Both males and females bellow loudly by sucking air into their lungs and blowing it out in intermittent, deep-toned roars that likely serve to advertise their presence.{{cite encyclopedia|last1=Reber |first1=Stephan A. |title=Crocodilia Communication |encyclopedia=Encyclopedia of Animal Cognition and Behavior |date=2018 |pages=1–10 |doi=10.1007/978-3-319-47829-6_950-1}}{{cite journal |last1=Jensen |first1=Thomas Rejsenhus |last2=Anikin |first2=Andrey |last3=Osvath |first3=Mathias |last4=Reber |first4=Stephan A. |title=Knowing a fellow by their bellow: acoustic individuality in the bellows of the American alligator |journal=Animal Behaviour |date=2024 |volume=207 |pages=157–167 |doi=10.1016/j.anbehav.2023.11.009|doi-access=free }} Males are known to use infrasound during mating bellows. Their bellowing initiates the beginning of the courtship period for American alligators.{{Cite journal |last1=JOANEN |first1=TED |last2=MCNEASE |first2=LARRY L. |date=August 1989 |title=Ecology and Physiology of Nesting and Early Development of the American Alligator |url=http://dx.doi.org/10.1093/icb/29.3.987 |journal=American Zoologist |volume=29 |issue=3 |pages=987–998 |doi=10.1093/icb/29.3.987 |issn=0003-1569}} Bellowing is performed in a "head oblique, tail arched" posture. Infrasonic waves from a bellowing male can cause the surface of the water directly over and to either side of his back to literally "sprinkle",[https://www.youtube.com/watch?v=ZIxl10Qvgw8 Male alligator "sprinkling" while bellowing in near-infrasound during courtship]. YouTube.com (April 28, 2010). Retrieved on 2016-09-07. in what is commonly called the "water dance".{{cite journal |last1=Garrick |first1=L. D. |last2=Lang |first2=J. W. |year=1977 |title=Social Displays of the American Alligator |volume=17 |journal=American Zoologist |pages=225–239 | doi = 10.1093/icb/17.1.225 |doi-access=free }} Large bellowing "choruses" of American alligators during the breeding season are commonly initiated by females and perpetuated by males.{{cite journal |last1=Garrick |first1=L. |last2=Lang |first2=J. |last3=Herzog |first3=H. |journal= American Zoologist |title=Social Signals of Adult American Alligators|year=1978|volume=60|issue=3|pages=153–192}} 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.{{cite news|last=Kilnkenberg|first=Jeff|title=Alligators in B Flat? Gatorland's denizens roar in ecstasy|url=https://www.tampabay.com/features/humaninterest/alligators-in-b-flat-gatorlands-denizens-roar-in-ecstasy/2127882/|newspaper=Tampa Bay Times|date=June 21, 2013 |quote="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.}}

American alligators typically live to the age of 50, and possibly over 70 years old. Males reach sexual maturity at around 11.6 years, and females at around 15.8 years. Although it was originally thought that American alligators never stop growing, studies have now found that males stop growing at around the age of 43 years, and females stop growing at around the age of 31 years.

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The breeding season begins in the spring. On spring nights, American alligators gather in large numbers for group courtship, in the aforementioned "water dances".{{cite journal |last=Dinets |first=V. L. | year=2010 |title=Nocturnal behavior of the American Alligator (Alligator mississippiensis) in the wild during the mating season |volume=111 |journal=Herpetological Bulletin |pages=4–11}} A study conducted in the 1980s at an alligator farm showed that homosexual courtship is common, with two-thirds of the recorded instances of sexual behaviour having been between two males.{{cite journal |last=Vilet |first=Kent A. |year=2000 |title=Courtship behaviour of American Alligators (Alligator mississippiensis) |url=https://www.alligatorfarm.com/images/Research/Courtship%20Behavior%20of%20American%20Alligators.pdf |journal=Crocodile Biology and Evolution |pages=383-408}} Multiple paternity thought to occur.{{Cite journal |last=Davis |first=Lisa M. |last2=Glenn |first2=Travis C. |last3=Elsey |first3=Ruth M. |last4=Dessauer |first4=Herbert C. |last5=Sawyer |first5=Roger H. |date=2001 |title=Multiple paternity and mating patterns in the American alligator, Alligator mississippiensis |url=https://onlinelibrary.wiley.com/doi/10.1046/j.1365-294X.2001.01241.x |journal=Molecular Ecology |language=en |volume=10 |issue=4 |pages=1011–1024 |doi=10.1046/j.1365-294X.2001.01241.x |issn=1365-294X}} The female builds a nest of vegetation, sticks, leaves, and mud in a sheltered spot in or near the water.

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. The temperature at which American alligator eggs develop determines their sex (see temperature-dependent sex determination). Studies have found that eggs hatched at a temperature below {{Convert|88.7|F}} or a temperature above {{Convert|94.1|F}} will produce female offspring, while those at a temperature between {{Convert|90.5 and 92.3|F}} will produce male offspring.{{Cite journal |last1=Bock |first1=Samantha L. |last2=Lowers |first2=Russell H. |last3=Rainwater |first3=Thomas R. |last4=Stolen |first4=Eric |last5=Drake |first5=John M. |last6=Wilkinson |first6=Philip M. |last7=Weiss |first7=Stephanie |last8=Back |first8=Brenton |last9=Guillette |first9=Louis |last10=Parrott |first10=Benjamin B. |date=2020-05-13 |title=Spatial and temporal variation in nest temperatures forecasts sex ratio skews in a crocodilian with environmental sex determination |journal=Proceedings of the Royal Society B: Biological Sciences |volume=287 |issue=1926 |pages=20200210 |doi=10.1098/rspb.2020.0210|pmid=32345164 |pmc=7282913 }} The nests built on levees are warmer, thus produce males, while the cooler nests of wet marsh produce females.{{cite journal |last1=Joanen |first1=T. |last2=Ferguson |first2=M. W. J. |year=1982 |title=Temperature of egg incubation determines sex in Alligator mississippiensis |journal=Nature |volume=296 |pages=850–53 |doi=10.1038/296850a0 |pmid=7070524 |issue=5860|bibcode=1982Natur.296..850F |s2cid=4307265 }} 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, as some other crocodilian species are known to do.

The young are tiny replicas of adults, with a series of yellow bands around their bodies that serve as camouflage. 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.{{cite journal|author1=Hunt, R. H. |author2=Watanabe, M. E. |year=1982|title=Observations on the maternal behavior of the American alligator, Alligator mississippiensis|journal=Journal of Herpetology|volume=16|issue=3|pages=235–39|jstor=1563716|doi=10.2307/1563716}} They are preyed on by large fish, birds, raccoons, Florida panthers, and adult American alligators. Mother American alligators eventually become more aggressive towards their young, which encourages them to disperse. Young American alligators grow {{convert|3|–|8|in|cm|abbr=on}} a year and reach adulthood at {{convert|6|ft|m|abbr=on}}.

American alligators are commonly infected with parasites. In a 2016 Texas study, 100% of the specimens collected were infected with parasites, and by at least 20 different species of parasites, including lung pentastomids, gastric nematodes, and intestinal helminths. When compared to American alligators from different states there was no significant difference in prevalence.{{cite journal |last1=Sung |first1=Helen |last2=Tellez |first2=Marisa |title=Spatial variation of parasite infracommunities in the American alligator (Alligator mississippiensis) |journal=The Southwestern Naturalist |date=December 2016 |volume=61 |issue=4 |pages=324–328 |doi=10.1894/0038-4909-61.4.324 |s2cid=90639824 |url=https://www.researchgate.net/publication/315917666}}

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.

Recently, a population of Burmese pythons became established in Everglades National Park. Substantial American alligator populations in the Everglades might be a contributing factor, as a competitor, in keeping the python populations low, preventing the spread of the species north. While events of predation by Burmese pythons on sizable American alligators have been observed,[https://www.nbcnews.com/id/wbna9600151 Gator-guzzling python comes to messy end]. Associated Press (October 5, 2005). Retrieved 2008-03-11.Butler, Rhett A. (October 5, 2005) [http://news.mongabay.com/2005/1005-gator.html Python explodes after swallowing 6-foot alligator in Florida Everglades]. Mongabay.com. Retrieved 2008-03-11. no evidence of a net negative effect has been seen on overall American alligator populations.United States Department of the Interior, U.S. Geological Survey (February 20, 2008). [http://www.usgs.gov/newsroom/article.asp?ID=1875 USGS Maps Show Potential Non-Native Python Habitat Along Three U.S. Coasts]. www.usgs.gov. Retrieved 2008-03-11.

Young American alligators have been documented consuming a large number of invasive Apple Snails in Northcentral Florida. This trend may be visible across other areas where the range of both species intersects. {{Cite journal |last=Delany |first=Michael F. |last2=Abercrombie |first2=C. L. |date=1986 |title=American Alligator Food Habits in Northcentral Florida |url=https://www.jstor.org/stable/3801926?origin=crossref |journal=The Journal of Wildlife Management |volume=50 |issue=2 |pages=348–353 |doi=10.2307/3801926 |issn=0022-541X}}

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American alligators play an important role in the restoration of the Everglades as biological indicators of restoration success.{{cite web |title=The American Alligator: An Indicator Species for Everglades Restoration |url=http://edis.ifas.ufl.edu/pdffiles/UW/UW35800.pdf |publisher=University of Florida IFAS Extension |last1=Harvey |first1=Rebecca G. |last2=Brandt |first2=Laura A. |last3=Mazzotti |first3=Frank J. |date=October 2011}} 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 nutria, which may otherwise overgraze marsh vegetation.Keddy, P.A., L. Gough, J.A. Nyman, T. McFalls, J. Carter and J. Siegrist (2009). [http://www.drpaulkeddy.com/pdffiles/Keddy_et_al_2009_alligator_trophic_cascade.pdf Alligator hunters, pelt traders, and runaway consumption of Gulf coast marshes: A trophic cascade perspective on coastal wetland losses.] {{Webarchive|url=https://web.archive.org/web/20141103232924/http://www.drpaulkeddy.com/pdffiles/Keddy_et_al_2009_alligator_trophic_cascade.pdf |date=November 3, 2014 }} 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}} [https://books.google.com/books?id=dZbvgaYT6JYC&pg=PA115 Google Books] In this way, the vital ecological service they provide may be important in reducing rates of coastal wetland losses in Louisiana.Keddy, P.A. (2010). Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. {{ISBN|0-521-78367-4}}. 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.{{cite web |last1=White |first1=C. |last2=Frederick |first2=P. |last3=Main |first3=M. |last4=Rodgers |first4=J. |title=Nesting Island Creation for Wading Birds |date=May 2005 |url=http://edis.ifas.ufl.edu/pdffiles/UW/UW22300.pdf |publisher=University of Florida IFAS Extension}}

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{{main|List of fatal alligator attacks in the United States}}

American alligators are capable of killing humans, but fatal attacks are 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.[http://www.sciencekids.co.nz/sciencefacts/animals/crocodilealligatordifferences.html Crocodile and Alligator Differences – Animal Facts for Kids]. Sciencekids.co.nz (July 11, 2012). Retrieved on 2012-08-21. 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.{{cite journal |last1=Harding |first1=Brett E. |last2=Wolf |first2=Barbara C. |title=Alligator Attacks in Southwest Florida |journal=Journal of Forensic Sciences |volume=51 |issue=3 |pages=674–677 |year=2006 |doi=10.1111/j.1556-4029.2006.00135.x |pmid=16696720 |s2cid=39551914 }}

As human populations increase, and as they build houses in low-lying areas, or fish or hunt near water, incidents are inevitable where humans intrude on American alligators and their habitats. 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.McLaughlin, Eliott C.; Almasy, Steve and Shoichet, Catherine E. (2016-06-16) [http://www.cnn.com/2016/06/16/us/alligator-attacks-child-disney-florida/index.html Disney alligator attack: Resort to add warning signs, source says]. CNN Only nine fatal attacks occurred in the United States throughout the 1970s–1990s, but American alligators killed 12 people between 2001 and 2007. An additional report of alligator attacks showed a total of 376 injuries and 15 deaths recorded all from 1948 to 2004, leading this to an increase of the alligator population.{{Cite journal |last=Langley |first=Ricky |date=September 1, 2005 |title=Alligator Attacks on Humans |journal=Wilderness & Environmental Medicine|volume=16 |issue=3 |pages=119–124 |doi=10.1580/1080-6032(2005)16[119:AAOHIT]2.0.CO;2 |pmid=16209465 |s2cid=37639089 |doi-access=free }} In May 2006, American alligators killed three Floridians in less than a week.{{cite news|url=https://www.nytimes.com/2006/05/15/us/15alligator.html |title=A String of Deaths by Gators in Florida |newspaper=nytimes.com |date=May 15, 2006 |access-date=May 15, 2006}} At least 28 fatal attacks by American alligators have occurred in the United States since 1970.

{{main|Alligator wrestling}}

File:GilletteAlligatorWrestling.jpg

Since the late 1880s, alligator wrestling has been a source of entertainment for some. Created by the Miccosukee and Seminole tribes for food prior to its popularity for tourism, this tourism tradition remains popular despite criticism from animal-rights activists.{{cite news|title=Alligator wrestling – cruelty or tradition?|publisher=BBC News.com|date=March 17, 2009|url=http://news.bbc.co.uk/2/hi/americas/7941699.stm|access-date=August 29, 2012}}

{{main|Alligator farm}}

File:FMIB 33999 Alligator Skins edited.png

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 {{convert|6|–|7|ft|m}} range have sold for $300 each.{{cite web|author1=Lane, Thomas J. |author2=Ruppert, Kathleen C. |date=June 2008|title=Alternative Opportunities for Small Farms:Alligator Production Review|publisher=University of Florida|access-date=August 29, 2012|url=http://myfwc.com/media/310209/Alligator_IFASrfac002.pdf}} The market for alligator meat is growing, and about {{Convert|300000|lb|kg}} of meat are produced annually.{{cite web|author=Reig Eimeric|year=2006|title=Gator Maters: Florida farmers find lucrative business mating alligators|publisher=Orange and Blue Magazine|access-date=August 29, 2012|url=http://www.jou.ufl.edu/pubs/onb/F06/index.php?id=9|url-status=dead|archive-url=https://web.archive.org/web/20130530231721/http://www.jou.ufl.edu/pubs/onb/F06/index.php?id=9|archive-date=May 30, 2013|df=mdy-all}} According to the Florida Department of Agriculture and Consumer Services, raw alligator meat contains {{convert|232|cal|kJ}} per {{convert|3.2|oz|g}} portion, of which {{convert|38|cal|kJ}} come from fat.{{cite web|url=https://www.fdacs.gov/Consumer-Resources/Buy-Fresh-From-Florida/Florida-Alligator-Meat-Skins-and-Hides|title=Florida Alligator Meat, Skins and Hides|website=Florida Department of Agriculture and Consumer Services|access-date=April 17, 2025}}

File:American alligator on grass.jpg

The American alligator is the official state reptile of Florida,{{cite web | url=http://www.flheritage.com/kids/symbol.cfm?id=3 | title=Alligator | publisher=Florida Division of Historical Resources | work=Florida State Symbols | year=2013 | access-date=April 6, 2013}} Louisiana,{{cite web | url=http://louisiana.gov/Explore/About_Louisiana/ | title=About Louisiana | publisher=State of Louisiana | work=Louisiana.gov | access-date=April 6, 2013 | archive-url=https://web.archive.org/web/20130324052614/http://louisiana.gov/Explore/About_Louisiana/ | archive-date=March 24, 2013 | url-status=dead }} and Mississippi.{{cite act |title=An Act To Designate The American Alligator As The State Reptile; And For Related Purposes |institution=Mississippi Legislature |number=2060 |date=July 1, 2005 |url=http://billstatus.ls.state.ms.us/documents/2005/pdf/SB/2001-2099/SB2060SG.pdf|access-date=April 6, 2013}} 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 1908, a printer made a spur-of-the-moment decision to print an alligator emblem on a shipment of the school's football pennants.{{cite web|title=History of the Gator|url=http://floridagators.com/sports/2015/12/10/_spirit_mascots_history_.aspx|website=Official website of Gator Athletics|publisher=University of Florida|access-date=17 October 2017}} The mascot stuck, and was made official in 1911, perhaps because the team captain's nickname was Gator.{{cite web|url=http://www.ufl.edu/history/1906.html |title=History: 1906–1927, early Gainesville |access-date=February 13, 2011 |publisher=University of Florida |archive-url=https://web.archive.org/web/20101231184043/http://www.ufl.edu/history/1906.html |archive-date=December 31, 2010 |url-status=dead }} Allegheny College and San Francisco State University both have Gators as their mascots, as well.{{cite web |url=https://alleghenygators.com/sports/2017/4/13/why-gators.aspx |title=Why Gators? |access-date=March 30, 2019 |publisher=Allegheny College}}

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.

• Chinese alligator, the other living species of alligator
• Muja, the oldest living American alligator in captivity, lived in Belgrade Zoo, Serbia
• Saturn, an American alligator that survived the destruction of the Berlin Zoological Garden during World War II
• The Alligator People
• Gatorland
• Brazos Bend State Park
• Sewer alligator

{{Reflist|30em}}

• Boulenger GA (1889). Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the British Museum (Natural History). New Edition. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). x + 311 pp. + Plates I-VI. (Alligator mississippiensis, p. 290).
• Daudin FM (1802). Histoire Naturelle, Générale et Particulière des Reptiles; Ouvrage faisant suite à l'Histoire Naturelle générale et particulière, composée par Leclerc de Buffon; et rédigée par C.S. Sonnini, membre de plusieurs sociétés savantes. Tome Second [Volume 2]. 432 pp. Paris: F. Dufart. ("Crocodilus mississipiensis [sic]", new species, pp. 412–416). (in French and Latin).
• Powell R, Conant R, Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 Plates, 207 Figures. {{ISBN|978-0-544-12997-9}}. (Alligator mississippiensis, p. 170 + Plate 13 + photographs on pp. 166–167, 465).
• Smith, Hobart M.; Brodie, Edmund D., Jr. (1982). Reptiles of North America: A Guide to Field Identification. New York: Golden Press. 240 pp. {{ISBN|0-307-13666-3}}. (Alligator mississippiensis, pp. 208–209).

{{Commons and category|Alligator mississippiensis|Alligator mississippiensis}}

{{Wikispecies|Alligator mississippiensis}}

• [http://www.crocodilian.com Crocodilian Online] {{Webarchive|url=https://web.archive.org/web/20110708204615/http://www.crocodilian.com/ |date=July 8, 2011 }}
• [https://www.floridamemory.com/learn/exhibits/photo_exhibits/alligators/ Photo exhibit on alligators in Florida] from State Archives of Florida
• [https://web.archive.org/web/20130827222507/http://drpaulkeddy.com/talks_--_alligators_and_nutria.html Why the Gulf Coast needs more big alligators]
• [http://www.fws.gov/video/sound.htm Alligator bellows and hisses] {{Webarchive|url=https://web.archive.org/web/20140301031934/http://www.fws.gov/video/sound.htm |date=March 1, 2014 }} – sound clips from the U.S. Fish and Wildlife Service
• {{UCSC genomes|allMis1}}

{{Crocodilia|A.}}

{{Crocs}}

{{North American Game}}

{{Taxonbar|from=Q193327}}

{{Authority control}}

{{DEFAULTSORT:Alligator, American}}

Category:Alligator

Category:Crocodilians of North America

Category:Reptiles of the United States

Category:Reptiles of Mexico

Category:Miocene reptiles of North America

Category:Extant Tortonian first appearances

Category:Fauna of the Southeastern United States

Category:Cuisine of the Southern United States

Category:Native American cuisine of the Southeastern Woodlands

Category:Apex predators

Category:Articles containing video clips

Category:Symbols of Florida

Category:Symbols of Louisiana

Category:Symbols of Mississippi

Category:Tool-using animals

Category:Natural history of Florida

Category:Reptiles described in 1802

Category:Taxa named by François Marie Daudin