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{{Short description|World's largest true toad}}
{{Other uses}}
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{{Speciesbox
| fossil_range = {{fossil range|13.8|0}}
| image = Canetoadmale.jpg
| image_caption = Adult male
| image2 = Canetoadfemale.jpg
| image2_caption = Adult female
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Frank Solís |author2=Roberto Ibáñez |author3=Geoffrey Hammerson |author4=Blair Hedges |author5=Arvin Diesmos |author6=Masafumi Matsui |author7=Jean-Marc Hero |author8=Stephen Richards |author9=Luis Coloma |author10=Santiago Ron |author11=Enrique La Marca |author12=Jerry Hardy |author13=Robert Powell |author14=Federico Bolaños |author15=Gerardo Chaves |author16=Paulino Ponce |date=2009 |title=''Rhinella marina'' |volume=2009 |article-number=e.T41065A10382424 |doi=10.2305/IUCN.UK.2009-2.RLTS.T41065A10382424.en |access-date=19 November 2021}}</ref>
| genus = Rhinella
| species = marina
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| range_map = Bufo marinus distribution.png
| range_map_caption = Distribution of the cane toad, native distribution in blue, introduced in red
| synonyms = * ''Rana marina'' <small>[[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]</small>
* ''Bufo marinus'' <small>Schneider, 1799</small>
* ''Rhinella marinus''<ref name="Frost, Darrel R. 2011">{{cite web | title = Amphibian Species of the World: an Online Reference. Version 5.5 | publisher = Frost, Darrel R. American Museum of Natural History, New York| date = 31 January 2011| url = http://research.amnh.org/vz/herpetology/amphibia/| access-date = June 4, 2012 }}</ref><ref name="Pramuk, Robertson, Sites, and Noonan 2008">{{cite journal | title = Around the world in 10 million years: biogeography of the nearly cosmopolitan true toads (Anura: Bufonidae)| journal = Global Ecology and Biogeography| pages = 070817112457001––| doi = 10.1111/j.1466-8238.2007.00348.x| year = 2007| last1 = Pramuk| first1 = Jennifer B.| last2 = Robertson| first2 = Tasia| last3 = Sites| first3 = Jack W.| last4 = Noonan| first4 = Brice P.| volume = 17}}</ref><ref name="CrosslandAlfordShine2009p626">{{Harvnb|Crossland|Alford|Shine|2009|p=626}}</ref>
* ''Chaunus marinus''<ref name="CrosslandAlfordShine2009p626" />
}}
[[File:Cane toad (Rhinella marina) Taveuni.jpg|thumb|on Taveuni, Fiji]]
The '''cane toad''' ('''''Rhinella marina'''''), also known as the '''giant neotropical toad''' or '''marine toad''', is a large, [[Terrestrial animal|terrestrial]] [[true toad]] native to [[South America|South]] and mainland [[Central America]], but which has been [[Introduced species|introduced]] to various islands throughout [[Oceania]] and the [[Caribbean]], as well as [[Northern Australia]]. It is a member of the genus ''[[Rhinella]]'', which includes many true toad [[species]] found throughout Central and South America, but it was formerly assigned to the genus ''[[Bufo]]''.

A fossil toad (specimen UCMP 41159) from the [[La Venta (Colombia)|La Venta fauna]] of the late [[Miocene]] in [[Colombia]] is morphologically indistinguishable from modern cane toads from northern South America. It was discovered in a floodplain deposit, which suggests the ''R. marina'' habitat preferences have long been for open areas. The cane toad is a prolific breeder; females lay single-clump [[spawn (biology)|spawns]] with thousands of [[egg (biology)|eggs]]. Its reproductive success is partly because of opportunistic feeding: it has a diet, unusual among [[Frog|anurans]], of both dead and living matter. Adults average {{convert|10|–|15|cm|in|abbr=on|0}} in length; the largest recorded specimen had a [[snout–vent length]] of {{convert|24|cm|in|abbr=on}}.

The cane toad has poison [[gland]]s, and the [[tadpole]]s are highly toxic to most animals if ingested. Its toxic skin can kill many animals, both wild and domesticated, and cane toads are particularly dangerous to dogs. Because of its voracious appetite, the cane toad has been introduced to many regions of the Pacific and the Caribbean islands as a method of agricultural [[pest control]]. The common name of the species is derived from its use against the [[cane beetle]] (''Dermolepida albohirtum''), which damages [[sugar cane]]. The cane toad is now considered a pest and an [[invasive species]] in many of its introduced regions. The 1988 film ''[[Cane Toads: An Unnatural History]]'' documented the trials and tribulations of the introduction of [[cane toads in Australia]].

==Taxonomy==
Historically, the cane toad was used to eradicate pests from [[sugarcane]], giving rise to its common name. The cane toad has many other common names, including "giant toad" and "marine toad"; the former refers to its size, and the latter to the [[binomial nomenclature|binomial name]], ''R. marina''. It was one of many species described by [[Carl Linnaeus]] in his 18th-century work ''[[10th edition of Systema Naturae|Systema Naturae]]'' (1758).<ref name="Linnaeus1758p824">{{Harvnb|Linnaeus|1758|p=824}}</ref> Linnaeus based the [[specific name (zoology)|specific epithet]] ''marina'' on an illustration by Dutch zoologist [[Albertus Seba]], who mistakenly believed the cane toad to inhabit both terrestrial and marine environments.<ref name="beltz2007">{{Harvnb|Beltz|2007}}</ref> Other common names include "giant neotropical toad",<ref name="Easteal1985p185">{{Harvnb|Easteal|van Beurden|Floyd|Sabath|1985|p=185}}</ref> "Dominican toad",<ref name="InvasiveSpeciesInfo">{{cite web | title = Cane Toad (''Bufo marinus'') | work = National Invasive Species Information Center | publisher = [[United States Department of Agriculture]] | date = June 15, 2009 | url = https://www.invasivespeciesinfo.gov/profile/cane-toad | access-date = June 17, 2009}}</ref> "giant marine toad",<ref name="Caughley1996">{{Harvnb|Caughley|Gunn|1996|p=140}}</ref> and "South American cane toad".<ref name="CSIROBiodiversity">{{Harvnb|Australian State of the Environment Committee|2002|p=107}}</ref> In [[Trinidad]]ian English, they are commonly called ''crapaud'', the French word for toad.<ref name="Kenny2008">{{Harvnb|Kenny|2008|p=35}}</ref>

The genus ''Rhinella'' is considered to constitute a distinct [[genus]] of its own, thus changing the [[scientific name]] of the cane toad. In this case, the [[Specific name (zoology)|specific name]] ''marinus'' ([[Grammatical gender|masculine]]) changes to ''marina'' (feminine) to conform with the rules of gender agreement as set out by the [[International Code of Zoological Nomenclature]], changing the binomial name from ''Bufo marinus'' to ''Rhinella marina''; the binomial ''Rhinella marinus'' was subsequently introduced as a synonym through misspelling by Pramuk, Robertson, Sites, and Noonan (2008).<ref name="Frost, Darrel R. 2011"/><ref name="Pramuk, Robertson, Sites, and Noonan 2008"/> Though controversial (with many traditional herpetologists still using ''Bufo marinus'') the binomial ''Rhinella marina'' is gaining in acceptance with such bodies as the [[IUCN]],<ref name="iucn status 19 November 2021" /> [[Encyclopaedia of Life]],<ref name= "Rhinella marina eol" >{{cite web | title = ''Rhinella marina'' | publisher = Encyclopaedia of Life | url = http://eol.org/pages/333309/overview | access-date = June 4, 2012 }}</ref> Amphibian Species of the World<ref name="Frost, Darrel R. 2011"/> and increasing numbers of scientific publications adopting its usage.

Since 2016, cane toad populations native to [[Mesoamerica]] and northwestern South America are sometimes considered to be a separate species, ''[[Rhinella horribilis]]''.<ref>{{cite web |title=Rhinella horribilis (Wiegmann, 1833) |url=https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Bufonidae/Rhinella/Rhinella-horribilis |website=Amphibians of the World 6.0 |publisher=American Museum of Natural History |access-date=19 April 2020}}</ref>

[[File:Cane-toad.jpg|thumb|left|alt=A large, adult cane toad, showing the light colouration present in some specimens of the species|Light-coloured cane toad]]

In Australia, the adults may be confused with large native frogs from the genera ''[[Limnodynastes]]'', ''[[Cyclorana]]'', and ''[[Barred frogs|Mixophyes]]''. These species can be distinguished from the cane toad by the absence of large [[parotoid gland]]s behind their eyes and the lack of a ridge between the nostril and the eye.<ref name="VanderduysEric2000p1">{{Harvnb|Vanderduys|Wilson|2000|p=1}}</ref> Cane toads have been confused with the [[giant burrowing frog]] (''Heleioporus australiacus''), because both are large and warty in appearance; however, the latter can be readily distinguished from the former by its vertical pupils and its silver-grey (as opposed to gold) [[iris (anatomy)|irises]].<ref name="BurrowingFrogAustralianMuseum">{{cite web | title = Giant Burrowing Frog | work = Wildlife of Sydney | publisher = [[Australian Museum]] | date = April 15, 2009 | url = https://australian.museum/learn/animals/frogs/giant-burrowing-frog/ | access-date = June 17, 2009 }}</ref> Juvenile cane toads may be confused with species of the genus ''[[Uperoleia]]'', but their adult colleagues can be distinguished by the lack of bright colouring on the groin and thighs.<ref name="BarkerGriggTyler1995p381">{{harvnb|Barker|Grigg|Tyler|1995|p=381}}</ref>

In the United States, the cane toad closely resembles many bufonid species. In particular, it could be confused with the [[southern toad]] (''Anaxyrus terrestris''), which can be distinguished by the presence of two bulbs in front of the parotoid glands.<ref name="BrandtMazzotti2005">{{Harvnb|Brandt|Mazzotti|2005|p=3}}</ref>

===Taxonomy and evolution===
The cane toad genome has been sequenced and certain Australian academics believe this will help in understanding how the toad can quickly evolve to adapt to new environments, the workings of its infamous toxin, and hopefully provide new options for halting this species' march across Australia and other places it has spread as an invasive pest.<ref>{{cite news |last1=Russo |first1=Alice |last2=White |first2=Peter |last3=Shine |first3=Rick |title=We've cracked the cane toad genome, and that could help put the brakes on its invasion |url=https://theconversation.com/weve-cracked-the-cane-toad-genome-and-that-could-help-put-the-brakes-on-its-invasion-103362|work=[[The Conversation (website)|The Conversation]]|access-date=26 December 2018}}</ref>

Studies of the genome confirm its evolutionary origins in northern part of South America and its close genetic relation to ''[[Rhinella diptycha]]'' and other similar species of the genus.<ref name="VallinotoSequeiraSodré2010">{{cite journal | last1 = Vallinoto | first1 = Marcelo | last2 = Sequeira | first2 = Fernando | last3 = Sodré | first3 = Davidson | last4 = Bernardi | first4 = José A. R. | last5 = Sampaio | first5 = Iracilda | last6 = Schneider | first6 = Horacio |title=Phylogeny and biogeography of the ''Rhinella marina'' species complex (Amphibia, Bufonidae) revisited: implications for Neotropical diversification hypotheses|journal=[[Zoologica Scripta]]| date = March 2010 | volume = 39 | issue = 2 | pages = 128–140 | issn = 0300-3256 | eissn = 1463-6409 | doi = 10.1111/j.1463-6409.2009.00415.x | pmid = | s2cid = 84074871 | url = }}</ref> Recent studies suggest that ''R. marina'' diverged between 2.75 and 9.40 million years ago.<ref name="RiveraPratesFirneno2021">{{cite journal | last1 = Rivera | first1 = Danielle | last2 = Prates | first2 = Ivan | last3 = Firneno | first3 = Thomas J. | last4 = Trefaut Rodrigues | first4 = Miguel | last5 = Caldwell | first5 = Janalee P. | last6 = Fujita | first6 = Matthew K.|title=Phylogenomics, introgression, and demographic history of South American true toads (''Rhinella'')|journal=[[Molecular Ecology (journal)|Molecular Ecology]]| date = 16 December 2021 | volume = 31 | issue = 3 | pages = 978–992 | issn = 0962-1083 | eissn = 1365-294X | doi = 10.1111/mec.16280 | pmid = 34784086 | hdl = 2027.42/171619 | s2cid = 244131909 | url = | hdl-access = free }}</ref>

A recent split in the species into further subspecies may have occurred approximately 2.7 million years ago following the isolation of population groups by the rising [[Northern Andes|Venezuelan Andes]].<ref name="SladeMoritz1998">{{cite journal | last1 = Slade | first1 = R.W. | last2 = Moritz | first2 = C. |title=Phylogeography of ''Bufo marinus'' from its natural and introduced ranges|journal=[[Proceedings of the Royal Society of London. Series B: Biological Sciences]]| date = 7 May 1998 | volume = 265 | issue = 1398 | pages = 769–777 | issn = 0962-8452 | eissn = 1471-2954 | doi = 10.1098/rspb.1998.0359 | pmid = 9628036 | pmc = 1689048 | url = }}</ref>

==Description==
[[File:Young Bufo marinus.jpg|thumb|left|Young cane toad|alt=A juvenile cane toad, showing many of the features of the adult toads, but without the large parotoid glands]]

Considered the largest species in the Bufonidae,<ref name="UWI"/> the cane toad is very large;<ref name="Robinson1998">{{Harvnb|Robinson|1998}}</ref> the females are significantly longer than males,<ref name="Lee2001p928">{{Harvnb|Lee|2001|page=928}}</ref> reaching a typical length of {{convert|10|-|15|cm|in|abbr=on|0}},<ref name="Robinson1998" /> with a maximum of {{convert|24|cm|in|abbr=on}}.{{sfn|Brandt|Mazzotti|2005}} Larger toads tend to be found in areas of lower population density.<ref name="Tyler1989p117">{{Harvnb|Tyler|1989|page=117}}</ref> They have a life expectancy of 10 to 15&nbsp;years in the wild,<ref name="Tyler1989p117-118">{{Harvnb|Tyler|1989|pages=117–118}}</ref> and can live considerably longer in captivity, with one specimen reportedly surviving for 35&nbsp;years.<ref name="Grenard2007p55">{{Harvnb|Grenard|2007|page=55}}</ref>

The skin of the cane toad is dry and warty.<ref name="Robinson1998" /> Distinct ridges above the eyes run down the snout.<ref name="VanderduysEric2000p1" /> Individual cane toads can be grey, yellowish, red-brown, or olive-brown, with varying patterns.<ref name="Cameron2009">{{Harvnb|Cameron|2009}}</ref> A large parotoid gland lies behind each eye.<ref name="Robinson1998" /> The ventral surface is cream-coloured and may have blotches in shades of black or brown. The pupils are horizontal and the irises golden.<ref name="BurrowingFrogAustralianMuseum" /> The toes have a fleshy webbing at their base,<ref name="Robinson1998" /> and the fingers are free of webbing.<ref name="Cameron2009" />

Typically, juvenile cane toads have smooth, dark skin, although some specimens have a red wash. Juveniles lack the adults' large parotoid glands, so they are usually less poisonous.<ref name="Tyler1989p117" />  The [[tadpole]]s are small and uniformly black, and are bottom-dwellers, tending to form [[Swarm|schools]].<ref name="Tyler1976p81">{{Harvnb|Tyler|1976|page=81}}</ref> Tadpoles range from {{convert|10|to|25|mm|in|abbr=on|1}} in length.<ref name="issgBufoMarinus">{{Harvnb|Invasive Species Specialist Group|2006}}</ref>

==Ecology, behaviour and life history==
[[File:CSIRO ScienceImage 1842 Cane Toad Spawn.jpg|thumb|Cane toad [[Spawn (biology)|spawn]]]]
The common name "marine toad" and the scientific name ''Rhinella marina'' suggest a link to [[marine biology|marine life]],<ref name="Tyler1989p116">{{Harvnb|Tyler|1989|page=116}}</ref> but cane toads do not live in the sea. However, laboratory experiments suggest that [[tadpoles]] can tolerate salt concentrations equivalent to 15% of [[seawater]] (~5.4‰),<ref name="Ely1944p256">{{Harvnb|Ely|1944|page=256}}</ref> and recent field observations found living tadpoles and toadlets at salinities of 27.5‰ on [[Coiba Island]], [[Panama]].<ref>{{cite journal | last1 = De León | first1 = L.F. | last2 = Castillo | first2 = A. | year = 2015 | title = ''Rhinella marina'' (Cane Toad). Salinity Tolerance | journal = Herpetological Review | volume = 46 | issue = 2| pages = 237–238 }}</ref>  The cane toad inhabits open grassland and woodland, and has displayed a "distinct preference" for areas modified by humans, such as gardens and drainage ditches.<ref name="Lever2001p3">{{Harvnb|Lever|2001|page=3}}</ref> In their native habitats, the toads can be found in subtropical forests,<ref name="issgBufoMarinus" /> although dense foliage tends to limit their dispersal.<ref name="BarkerGriggTyler1995p380">{{harvnb|Barker|Grigg|Tyler|1995|p=380}}</ref>

The cane toad begins life as an egg, which is laid as part of long strings of jelly in water. A female lays 8,000–25,000 eggs at once and the strings can stretch up to {{convert|20|m|ft|abbr=on}} in length.<ref name="Tyler1989p116" /> The black eggs are covered by a membrane and their diameter is about {{convert|1.7|-|2.0|mm|in|abbr=on}}.<ref name="Tyler1989p116" /> The rate at which an egg grows into a tadpole increases with temperature. Tadpoles typically hatch within 48&nbsp;hours, but the period can vary from 14&nbsp;hours to almost a week.<ref name="Tyler1989p116" /> This process usually involves thousands of tadpoles—which are small, black, and have short tails—forming into groups. Between 12 and 60&nbsp;days are needed for the tadpoles to develop into juveniles, with four weeks being typical.<ref name="Tyler1989p116" /> Similarly to their adult counterparts, eggs and tadpoles are toxic to many animals.<ref name="Robinson1998" />

When they emerge, toadlets typically are about {{convert|10|–|11|mm|in|abbr=on}} in length, and grow rapidly. While the rate of growth varies by region, time of year, and sex, an average initial growth rate of {{convert|0.647|mm|in|abbr=on}} per day is seen, followed by an average rate of {{convert|0.373|mm|in|abbr=on}} per day. Growth typically slows once the toads reach sexual maturity.<ref name="ZugZug1979pp14-15">{{Harvnb|Zug|Zug|1979|pages=14–15}}</ref> This rapid growth is important for their survival; in the period between metamorphosis and subadulthood, the young toads lose the toxicity that protected them as eggs and tadpoles, but have yet to fully develop the parotoid glands that produce [[bufotoxin]].<ref name="ZugZug1979p15">{{Harvnb|Zug|Zug|1979|page=15}}</ref> Only an estimated 0.5% of cane toads reach adulthood, in part because they lack this key defense<ref name="Tyler1989p117" /><ref name="Anstis2002p274">{{Harvnb|Anstis|2002|page=274}}</ref>—but also due to tadpole cannibalism. Although cannibalism does occur in the native population in South America, the [[rapid evolution]] occurring in the unnaturally large population in Australia has produced tadpoles 30x more likely to be ''interested'' in cannibalising their siblings, and 2.6x more likely to actually ''do so''. They have also evolved to shorten their tadpole phase in response to the presence of older tadpoles. These changes are likely genetic, although no genetic basis has been determined.<ref name="Kozlov-2021">{{cite journal | last=Kozlov | first=Max | title=Australia's cane toads evolved as cannibals with frightening speed | journal=[[Nature (journal)|Nature]] | publisher=[[Nature Portfolio]] | volume=597 | issue=7874 | date=2021-08-25 | issn=0028-0836 | doi=10.1038/d41586-021-02317-9 | pages=19–20| pmid=34433984 | bibcode=2021Natur.597...19K | s2cid=237305658 }}</ref>

As with rates of growth, the point at which the toads become sexually mature varies across different regions. In New Guinea, sexual maturity is reached by female toads with a snout–vent length between {{convert|70|and|80|mm|in|abbr=on}}, while toads in [[Panama]] achieve maturity when they are between {{convert|90|and|100|mm|in|abbr=on}} in length.<ref name="ZugZug1979p8">{{Harvnb|Zug|Zug|1979|page=8}}</ref> In tropical regions, such as their native habitats, breeding occurs throughout the year, but in subtropical areas, breeding occurs only during warmer periods that coincide with the onset of the [[wet season]].<ref name="Lever2001p6">{{Harvnb|Lever|2001|page=6}}</ref>

The cane toad is estimated to have a critical thermal maximum of {{convert|40|-|42|C|F}} and a minimum of around {{convert|10|-|15|C|F}}.<ref name="Tyler1989p118">{{Harvnb|Tyler|1989|page=118}}</ref> The ranges can change due to adaptation to the local environment.<ref name="Tyler1989p119">{{Harvnb|Tyler|1989|page=119}}</ref> Cane toads from some populations can adjust their thermal tolerance within a few hours of encountering low temperatures.<ref name=":0">{{Cite journal|last1=McCann|first1=Samantha|last2=Greenlees|first2=Matthew J.|last3=Newell|first3=David|last4=Shine|first4=Richard|date=2014|title=Rapid acclimation to cold allows the cane toad to invade montane areas within its Australian range|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1365-2435.12255|journal=Functional Ecology|language=en|volume=28|issue=5|pages=1166–1174|doi=10.1111/1365-2435.12255|bibcode=2014FuEco..28.1166M |issn=1365-2435|url-access=subscription}}</ref> The toad is able to rapidly acclimate to the cold using physiological plasticity, though there is also evidence that more northerly populations of cane toads in the United States are better cold-adapted than more southerly populations.<ref>{{Cite journal|last1=Mittan|first1=Cinnamon S|last2=Zamudio|first2=Kelly R|date=2019-01-01|title=Rapid adaptation to cold in the invasive cane toadRhinella marina|journal=Conservation Physiology|volume=7|issue=1|article-number=coy075|doi=10.1093/conphys/coy075|issn=2051-1434|pmc=6379050|pmid=30800317}}</ref> These adaptations have allowed the cane toad to establish invasive populations across the world. The toad's ability to rapidly acclimate to thermal changes suggests that current models may underestimate the potential range of habitats that the toad can populate.<ref name=":0" /> The cane toad has a high tolerance to water loss; some can withstand a 52.6% loss of body water, allowing them to survive outside tropical environments.<ref name="Tyler1989p119" />

===Diet===
Most frogs identify prey by movement, and vision appears to be the primary method by which the cane toad detects prey; however, it can also locate food using its sense of smell.<ref name="Lever2001p10">{{Harvnb|Lever|2001|page=10}}</ref> They eat a wide range of material; in addition to the normal prey of small [[rodent]]s, other small [[mammal]]s,<ref name="UWI">{{cite web|url=https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/documents/ogatt/Rhinella_marina%20-%20Cane%20Toad%20or%20Crapaud.pdf|title=''Rhinella marina'' (Cane Toad or Crapaud)|website=Sta.uwi.edu|access-date=11 June 2022}}</ref> [[reptile]]s, other [[amphibian]]s, [[bird]]s, and even [[bat]]s and a range of [[invertebrate]]s (such as [[ant]]s, [[beetle]]s, [[earwig]]s, [[dragonflies]], [[grasshopper]]s, [[true bug]]s, [[crustacean]]s, and [[gastropod]]s),<ref name="Rhinella marina Cane Toad">{{Cite web|url=https://animaldiversity.org/accounts/Rhinella_marina/|title = ''Rhinella marina'' (Cane Toad)|website=Animaldiversity.org}}</ref> they also eat plants, dog food, cat food,<ref name="Rhinella marina Cane Toad"/> feces,<ref name="UWI"/> and household refuse.<ref name="Tyler1989pp130-132">{{Harvnb|Tyler|1989|pages=130–132}}</ref><ref>{{cite journal | last1 = Mikula | first1 = P | year = 2015 | title = Fish and amphibians as bat predators | journal = European Journal of Ecology | volume = 1 | issue = 1| pages = 71–80 | doi = 10.1515/eje-2015-0010 | doi-access = free }}</ref>

===Defences===
[[File:Bufo marinus01e.jpg|thumb|left|Specimen from [[El Salvador]]: The large parotoid glands are visible behind the eyes.|alt=An adult cane toad with dark colouration, as found in El Salvador: The parotoid gland is prominently displayed on the side of the head.]]

The skin of the adult cane toad is toxic, as well as the enlarged parotoid glands behind the eyes, and other glands across its back. When the toad is threatened, its glands secrete a milky-white fluid known as [[bufotoxin]].<ref name="Tyler1989p134">{{Harvnb|Tyler|1989|page=134}}</ref> Components of bufotoxin are toxic to many animals;<ref name="Tyler1989pp134-136">{{Harvnb|Tyler|1989|pages=134–136}}</ref> even human deaths have been recorded due to the consumption of cane toads.<ref name="issgBufoMarinus" />  Dogs are especially prone to be poisoned by licking or biting toads. Pets showing excessive drooling, extremely red gums, head-shaking, crying, loss of coordination, and/or convulsions require immediate veterinary attention.{{sfn|Brandt|Mazzotti|2005}}

[[Bufotenin]], one of the chemicals excreted by the cane toad, is classified as a schedule 9 drug under Australian law, alongside [[heroin]] and [[lysergic acid diethylamide|LSD]].<ref>{{cite web |title=Poisons Standard (No.2) June 2020 |url=https://www.legislation.gov.au/Details/F2020L00639/Html/Text#_Toc28084712 |website=Legislation.gov.au |publisher=Australian Government |access-date=7 June 2020 |language=en |date=June 2020}}</ref> The effects of bufotenin are thought to be similar to those of mild poisoning; the stimulation, which includes mild [[hallucination]]s, lasts less than an hour.<ref name="Fawcett2004-08-04p9">{{Harvnb|Fawcett|2004|page=9}}</ref> As the cane toad excretes bufotenin in small amounts, and other toxins in relatively large quantities, [[Psychoactive toad|toad licking]] could result in serious illness or death.<ref name="Weil1994pp1-8">{{Harvnb|Weil|Davis|1994|pages=1–8}}</ref>

In addition to releasing toxin, the cane toad is capable of inflating its lungs, puffing up, and lifting its body off the ground to appear taller and larger to a potential predator.<ref name="Tyler1989p134" />

Since 2011, experimenters in the Kimberley region of Western Australia have used poisonous sausages containing toad meat in an attempt to protect native animals from cane toads' deadly impact. The Western Australian Department of Environment and Conservation, along with the University of Sydney, developed these sausage-shaped baits as a tool in order to train native animals not to eat the toads. By blending bits of toad with a nausea-inducing chemical, the baits train the animals to stay away from the amphibians.<ref>{{cite web |url=http://www.abc.net.au/news/2011-12-15/can-toad-sausages-trialled-in-wa/3732836|date=15 December 2011 |title=Cane toad sausages served up in the Kimberley|publisher=ABC |access-date=2 March 2019}}</ref><ref>{{cite news|url=https://www.theguardian.com/environment/2018/mar/19/wild-quolls-take-bait-of-cane-toad-sausages-offering-hope-for-species|title=Wild quolls take bait of cane-toad sausages, offering hope for species|newspaper=[[The Guardian]]|access-date=2 March 2019|date=19 March 2018|first=Amy|last=McNeilage}}</ref><ref>{{cite web|url=https://www.abc.net.au/news/2018-06-16/toad-sausages-dropped-from-helicopters/9857520|title=First helicopter drops of cane toad sausages prompt design tweak|first=Erin|last=Parke|publisher=ABC|date=15 June 2018|access-date=2 March 2019}}</ref>

Young cane toads that aren't lethal upon ingestion have also been used to teach native predators avoidance, namely [[yellow-spotted monitor]]s. 200,000 metamorphs, tadpoles, and eggs in total were released in areas ahead of inevitable invasion fronts. Following invasion by wild cane toads, yellow-spotted monitors in control areas bereft of the "teacher toads" were virtually wiped out, but experimental areas still contained substantial populations of yellow-spotted monitors.<ref>{{Cite journal |last1=Ward-Fear |first1=Georgia |last2=Rangers |first2=Bunuba |last3=Bruny |first3=Miles |last4=Everitt |first4=Corrin |last5=Shine |first5=Richard |date=2024-04-08 |title=Teacher toads: Buffering apex predators from toxic invaders in a remote tropical landscape |journal=Conservation Letters |volume=17 |issue=3 |article-number=e13012 |language=en |doi=10.1111/conl.13012 |issn=1755-263X|doi-access=free |bibcode=2024ConL...17E3012W }}</ref>

===Predators===
[[File:Kookaburra with Cane Toad - AndrewMercer - DSC00046.jpg|thumb|[[Laughing kookaburra]] (''Dacelo novaeguineae'') preying on a juvenile cane toad]]
Many species prey on the cane toad and its tadpoles in its native habitat, including the [[broad-snouted caiman]] (''Caiman latirostris''), the banded cat-eyed snake (''[[Leptodeira annulata]]''), eels (family [[Anguillidae]]), various species of [[killifish]],<ref name="Tyler1989pp138-139" />  and ''[[Paraponera clavata]]'' (bullet ants).<ref>{{Cite journal |last=Morrison |first=Colin R. |date=November 2018 |title=Predation of top predators: cane toad consumption of bullet ants in a Panamanian lowland wet forest |url=https://www.cambridge.org/core/journals/journal-of-tropical-ecology/article/abs/predation-of-top-predators-cane-toad-consumption-of-bullet-ants-in-a-panamanian-lowland-wet-forest/31E056A8BE4E3DAECE661E8E2A7E0ED6 |journal=Journal of Tropical Ecology |language=en |volume=34 |issue=6 |pages=390–394 |doi=10.1017/S0266467418000342 |issn=0266-4674|url-access=subscription }}</ref>

Predators outside the cane toad's native range include the rock flagtail (''[[Kuhlia rupestris]]''), some species of [[catfish]] (order Siluriformes), some species of [[ibis]] (subfamily Threskiornithinae),<ref name="Tyler1989pp138-139">{{Harvnb|Tyler|1989|page=138–139}}</ref> the [[whistling kite]] (''Haliastur sphenurus''), the [[rakali]] (''Hydromys chrysogaster''), the [[black rat]] (''Rattus rattus'') and the [[Asian water monitor|water monitor]] (''Varanus salvator''). The [[tawny frogmouth]] (''Podargus strigoides'') and the [[Papuan frogmouth]] (''Podargus papuensis'')<ref name="Angus1994pp10-11">{{Harvnb|Angus|1994|pages=10–11}}</ref> have been reported as feeding on cane toads; some Australian crows (''[[Corvus]]'' spp.) have also learned strategies allowing them to feed on cane toads, such as using their beak to flip toads onto their backs.<ref>{{cite web|first=Katrina|last=Bolton |url=http://www.abc.net.au/news/stories/2007/09/15/2033759.htm |archive-url=https://web.archive.org/web/20071209125627/http://www.abc.net.au/news/stories/2007/09/15/2033759.htm |archive-date=December 9, 2007 |title=Toads fall victim to crows in NT – ABC News (Australian Broadcasting Corporation) |publisher=Abc.net.au |date=2007-09-15 |access-date=2011-11-12}}</ref><ref>{{cite web|url=http://www.ozanimals.com/Frog/Cane-Toad/Bufo/marinus.html |title=Cane Toad (''Bufo marinus'') |publisher=Ozanimals.com |access-date=2011-11-12}}</ref> [[Kookaburra]]s also prey on the amphibians.<ref>{{Cite news |date=2019-10-31 |title=The native animals that turn cane toads into tucker |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/science/2019-11-01/cane-toad-native-animals-eating/11649498 |access-date=2023-10-06}}</ref>

Opossums of the genus ''[[Didelphis]]'' likely can eat cane toads with impunity.<ref>{{cite web|url=http://www.abc.net.au/rn/scienceshow/stories/2010/2850936.htm |title=American possums the solution to cane toads in Australia? – Science Show – 20 March 2010 |publisher=Abc.net.au |access-date=2010-04-26 |archive-url=https://web.archive.org/web/20100322225724/http://www.abc.net.au/rn/scienceshow/stories/2010/2850936.htm <!--Added by H3llBot--> |archive-date=2010-03-22|date=2010-03-19 }}</ref> [[Meat ant]]s are unaffected by the cane toads' toxins, so are able to kill them without reaction.<ref>{{cite news|url=http://www.timesonline.co.uk/tol/news/environment/article6007268.ece|title=Killer ants are weapons of mass toad destruction|last=Sweeney|first=Claire|newspaper=Times Online|access-date=2009-03-31 | location=London | date=31 March 2009}}{{dead link|date=September 2024|bot=medic}}{{cbignore|bot=medic}}</ref> The cane toad's normal response to attack is to stand still and let its toxin kill or repel the attacker, which allows the ants to attack and eat the toad.<ref>{{cite web|url=http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Frogs/Cane+Toad|title=Cane Toads|publisher=Queensland Museum|access-date=2012-07-31|archive-url=https://web.archive.org/web/20150322180305/http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Frogs/Cane+Toad|archive-date=2015-03-22}}</ref> [[Saw-shelled turtle]]s have also been seen successfully and safely eating cane toads.

In Australia, [[rakali]] (Australian water rats) learnt in two years how to eat cane toads safely. They select the largest toads, turn them over, remove the poisonous gallbladder, and eat the heart and other organs with "surgical precision". They remove the toxic skin and eat the thigh muscle. Other animals such as crows and kites turn cane toads inside out and eat non-poisonous organs, also thus avoiding the skin.<ref>{{cite news| last=Zhou | first=Naaman | title=Australian water rats cut cane toads open with 'surgical precision' to feast on their hearts |newspaper=The Guardian | date=25 October 2019 | url=https://www.theguardian.com/world/2019/oct/26/australian-water-rats-cut-cane-toads-open-with-surgical-precision-to-feast-on-their-hearts}}</ref>

==Distribution==
The cane toad is native to the Americas, and its range stretches from the [[Rio Grande Valley (Texas)|Rio Grande Valley]] in [[South Texas]] to the central [[Amazon basin|Amazon]] and southeastern [[Peru]], and some of the continental islands near [[Venezuela]] (such as [[Trinidad]] and [[Tobago]]).<ref name="Tyler1989p111" /><ref name="ZugZug1979p1-2">{{Harvnb|Zug|Zug|1979|pages=1–2}}</ref> This area encompasses both [[tropics|tropical]] and [[Semi-arid climate|semiarid]] environments. The density of the cane toad is significantly lower within its native distribution than in places where it has been introduced. In South America, the density was recorded to be 20 adults per {{convert|100|m|yd|abbr=on}} of shoreline, 1 to 2% of the density in Australia.<ref name="LampoDeLeo1998p392">{{Harvnb|Lampo|De Leo|1998|page=392}}</ref>

===As an introduced species===
The cane toad has been introduced to many regions of the world—particularly the Pacific—for the biological control of agricultural pests.<ref name="Tyler1989p111">{{Harvnb|Tyler|1989|page=111}}</ref> These introductions have generally been well documented, and the cane toad may be one of the most studied of any [[introduced species]].<ref name="Easteall981p94">{{Harvnb|Easteal|1981|page=94}}</ref>

Before the early 1840s, the cane toad had been introduced into [[Martinique]] and [[Barbados]], from [[French Guiana]] and [[Guyana]].<ref name="Easteal1981p96">{{Harvnb|Easteal|1981|page=96}}</ref> An introduction to [[Jamaica]] was made in 1844 in an attempt to reduce the rat population.<ref name="Lannoo2005p417">{{Harvnb|Lannoo|2005|page=417}}</ref> Despite its failure to control the rodents, the cane toad was introduced to [[Puerto Rico]] in the early 20th century in the hope that it would counter a beetle infestation ravaging the sugarcane plantations. The Puerto Rican scheme was successful and halted the economic damage caused by the beetles, prompting scientists in the 1930s to promote it as an ideal solution to agricultural pests.<ref name="Tyler1989p112-113">{{Harvnb|Tyler|1989|pages=112–113}}</ref>

As a result, many countries in the Pacific region emulated the lead of Puerto Rico and introduced the toad in the 1930s.<ref name="Tyler1989p113-114">{{Harvnb|Tyler|1989|pages=113–114}}</ref> Introduced populations are in [[Australia]]; [[Florida]];<ref name="Smith2005p433-441">{{Harvnb|Smith|2005|pages=433–441}}</ref> [[Papua New Guinea]];<ref name="ZugLindgremPippet1975p31-50">{{Harvnb|Zug|Lindgrem|Pippet|1975|pages=31–50}}</ref> the [[Philippines]];<ref name="Alcala1957p90-96">{{Harvnb|Alcala|1957|pages=90–96}}</ref> [[Ishigaki Island]], the [[Ogasawara Islands|Ogasawara]], and the [[Daitō Islands]] of Japan;<ref name="KideraEtAl2008p423-440">{{Harvnb|Kidera|Tandavanitj|Oh|Nakanishi|2008|pages=423–440}}</ref> [[Taiwan]]'s [[Nantou County|Nantou]] [[Caotun]];<ref>{{cite web|url=https://www.taipeitimes.com/News/taiwan/archives/2021/12/07/2003769158|title=Cane toad invasion raises alarm in Nantou|last=Sean Chang|first=Sean Chang|publisher=Sean Chang|date=December 7, 2021|website=Taiwan News of Taipeitimes|access-date=October 16, 2022}}</ref> most Caribbean islands;<ref name="Tyler1989p113-114"/> and [[Fiji]] and many other Pacific islands,<ref name="Tyler1989p113-114"/> including [[Hawaii|Hawaiʻi]].<ref name="OliverShaw1953p65-95">{{Harvnb|Oliver|Shaw|1953|pages=65–95}}</ref><ref name="Hinckley1963p253-259">{{Harvnb|Hinckley|1963|pages=253–259}}</ref> Since then, the cane toad has become a pest in many host countries, and poses a serious threat to native animals.<ref name="Tyler1989p113" />

=== Australia ===
{{Main|Cane toads in Australia}}
Following the apparent success of the cane toad in eating the beetles threatening the sugarcane plantations of Puerto Rico, and the fruitful introductions into Hawaiʻi and the Philippines, a strong push was made for the cane toad to be released in Australia to negate the pests ravaging the Queensland cane fields.<ref name="Tyler1976p77">{{Harvnb|Tyler|1976|page=77}}</ref> As a result, 102 toads were collected from Hawaiʻi and brought to Australia.<ref name="Easteall981p104">{{Harvnb|Easteal|1981|page=104}}</ref> Queensland's sugar scientists released the toad into cane fields in August 1935.<ref>{{Cite book|title=Cane toads: a tale of sugar, politics and flawed science|last=Turvey, Nigel D.|publisher=Sydney University Press|year=2013|isbn=978-1-74332-359-5|location=Sydney, NSW|pages=3|oclc=857766002}}</ref> After this initial release, the Commonwealth Department of Health decided to ban future introductions until a study was conducted into the feeding habits of the toad. The study was completed in 1936 and the ban lifted, and large-scale releases were undertaken; by March 1937, 62,000 toadlets had been released into the wild.<ref name="Easteall981p104" /><ref name=autogenerated1>{{Harvnb|Tyler|1976|pages=78–79}}</ref> The toads became firmly established in Queensland, increasing exponentially in number and extending their range into the [[Northern Territory]] and [[New South Wales]].<ref name="Cameron2009" /><ref name="Easteall981p104" /> In 2010, one was found on the far western coast in [[Broome, Western Australia]].<ref>[http://www.australiangeographic.com.au/news/2010/07/cane-toad-found-on-wa-coast/ Cane toad found on WA coast], ''Australian Geographic'', July 21, 2010</ref>

However, the toad was generally unsuccessful in reducing the targeted grey-backed cane beetles (''[[Dermolepida albohirtum]]''), in part because the cane fields provided insufficient shelter for the predators during the day,<ref name="Tyler1976p83">{{Harvnb|Tyler|1976|page=83}}</ref> and in part because the beetles live at the tops of sugar cane—and cane toads are not good climbers.<ref name="Tyler1976p77"/> Since its original introduction, the cane toad has had a particularly marked effect on Australian [[biodiversity]]. The population of a number of native predatory reptiles has declined, such as the [[Monitor lizard|varanid]] lizards ''[[Mertens' water monitor|Varanus mertensi]]'', ''[[Mitchell's water monitor|V. mitchelli]]'', and ''[[Yellow-spotted monitor|V. panoptes]]''; the land snakes ''[[King brown snake|Pseudechis australis]]'' and ''[[Common death adder|Acanthophis antarcticus]]''; and the freshwater crocodile species ''[[Freshwater crocodile|Crocodylus johnstoni]]''. In contrast, the population of the [[agamidae|agamid]] lizard ''[[Lophognathus gilberti]]''—known to be a prey item of ''V. panoptes''—has increased.<ref name="DoodyEtAl2009p46-53">{{Harvnb|Doody|Green|Rhind|Castellano|2009|pages=46–53}}. On snake populations see {{Harvnb|Shine|2009|p=20}}.</ref> [[Meat ant]]s, however, are able to kill cane toads.<ref name="meat_ants_2022">[https://aepma.com.au/PestDetail/10/Meat ''Meat Ant.''] Australian Environmental Pest Managers Association (AEPMA) (accessed July 2022)</ref> The cane toad has also been linked to decreases in [[northern quoll]]s in the southern region of [[Kakadu National Park]] and even their [[local extinction]].<ref name=environment>{{Cite web|url = https://www.environment.gov.au/biodiversity/threatened/key-threatening-processes/biological-effects-cane-toads|title = The biological effects, including lethal toxic ingestion, caused by Cane Toads (''Bufo marinus'')|date = April 12, 2005|access-date = October 29, 2015|website = www.environment.gov.au}}</ref>

===Caribbean===
The cane toad was introduced to various Caribbean islands to counter a number of pests infesting local crops.<ref name="Lever2001p67">{{Harvnb|Lever|2001|page=67}}</ref> While it was able to establish itself on some islands, such as [[Barbados]], [[Jamaica]], [[Hispaniola]], and [[Puerto Rico]], other introductions, such as in [[Cuba]] before 1900 and in 1946, and on the islands of [[Dominica]] and [[Grand Cayman]], were unsuccessful.<ref name="Lever2001p73-74">{{Harvnb|Lever|2001|pages=73–74}}</ref>

The earliest recorded introductions were to Barbados and [[Martinique]]. The Barbados introductions were focused on the biological control of pests damaging the sugarcane crops,<ref name="Lever2001p71">{{Harvnb|Lever|2001|page=71}}</ref> and while the toads became abundant, they have done even less to control the pests than in Australia.<ref name="KennedyLever2001p72">Kennedy, Anthony quoted in {{Harvnb|Lever|2001|page=72}}</ref> The toad was introduced to Martinique from [[French Guiana]] before 1944 and became established. Today, they reduce the [[mosquito]] and [[mole cricket]] populations.<ref name="Lever2001p81">{{Harvnb|Lever|2001|page=81}}</ref> A third introduction to the region occurred in 1884, when toads appeared in Jamaica, reportedly imported from Barbados to help control the rodent population. While they had no significant effect on the rats, they nevertheless became well established.<ref name="Lever2001p78-79">{{Harvnb|Lever|2001|pages=78–79}}</ref> Other introductions include the release on [[Antigua]]—possibly before 1916, although this initial population may have died out by 1934 and been reintroduced at a later date<ref name="Easteal1981p98">{{Harvnb|Easteal|1981|page=98}}</ref>—and [[Montserrat]], which had an introduction before 1879 that led to the establishment of a solid population, which was apparently sufficient to survive the [[Soufrière Hills|Soufrière Hills volcano]] eruption in 1995.<ref name="Lever2001p81-82">{{Harvnb|Lever|2001|pages=81–82}}</ref>

In 1920, the cane toad was introduced into Puerto Rico to control the populations of [[Phyllophaga|white grub]] (''Phyllophaga'' spp.), a sugarcane pest.<ref name="Tyler1989p112">{{Harvnb|Tyler|1989|page=112}}</ref> Before this, the pests were manually collected by humans, so the introduction of the toad eliminated labor costs.<ref name="Tyler1989p112" /> A second group of toads was imported in 1923, and by 1932, the cane toad was well established.<ref name="VanVolkenberg1935">{{Harvnb|Van Volkenberg|1935|pages=278–279}}. "After a completely successful method of killing white grubs by chemical means was found, the only opportunities for its use in Puerto Rico have been limited to small areas in pineapple plantations at elevations where the toad is even yet not present in sufficient abundance."</ref> The population of white grubs dramatically decreased,<ref name="Tyler1989p112" /> and this was attributed to the cane toad at the annual meeting of the International Sugar Cane Technologists in Puerto Rico.<ref name="Tyler1989p113">{{Harvnb|Tyler|1989|page=113}}</ref> However, there may have been other factors.<ref name="Tyler1989p113" /> The six-year period after 1931—when the cane toad was most prolific, and the white grub had a dramatic decline—had the highest-ever rainfall for Puerto Rico.<ref name="Freeland1985p211-215">{{Harvnb|Freeland|1985|pages=211–215}}</ref> Nevertheless, the cane toad was assumed to have controlled the white grub; this view was reinforced by a ''[[Nature (journal)|Nature]]'' article titled "Toads save sugar crop",<ref name="Tyler1989p113" /> and this led to large-scale introductions throughout many parts of the Pacific.<ref name="Tyler1989p113-115">{{Harvnb|Tyler|1989|pages=113–115}}</ref>

The cane toad has been spotted in [[Carriacou]] and [[Dominica]], the latter appearance occurring in spite of the failure of the earlier introductions.<ref name="Lever2001p72-73">{{Harvnb|Lever|2001|pages=72–73}}</ref>  On September 8, 2013, the cane toad was also discovered on the island of [[New Providence]] in the Bahamas.<ref>{{cite web|url=http://www.tribune242.com/news/2013/sep/06/killer-toad-found-new-providence/|title=Killer Toad Found in New Providence |publisher=Tribute 242|access-date=2013-09-07}}</ref>

===The Philippines===
[[File:Bufo marinus (Philippines).jpg|thumb|''R. marina'' in the [[Philippines]] are referred to as ''kamprag'', a corruption of 'American frog'.<ref name="kamprag"/>]]

The cane toad was first introduced deliberately into the [[Philippines]] in 1930 as a biological control agent of pests in sugarcane plantations, after the success of the experimental introductions into Puerto Rico.<ref name="piper">{{cite book|author=Ross Piper|title =Pests: A Guide to the World's Most Maligned, Yet Misunderstood Creatures|publisher =ABC-CLIO|year =2011|page=236|isbn =978-0-313-38426-4|url =https://books.google.com/books?id=nlSX5kDnd78C&q=Bufo%20marinus%20philippines%201930&pg=PA236|author-link =Ross Piper}}</ref><ref name="diesmos">{{cite journal|author1=Arvin C. Diesmos |author2=Mae L. Diesmos |author3=Rafe M. Brown |year=2005|title=Status and Distribution of Alien Invasive Frogs in the Philippines |journal=Journal of Environmental Science and Management |volume=9|issue=2|pages=41–53|issn=0119-1144}}</ref> It subsequently became the most ubiquitous amphibian in the islands. It still retains the common name of ''bakî'' or ''kamprag'' in the [[Visayan languages]], a [[Corruption (linguistics)|corruption]] of 'American frog', referring to its origins.<ref name="kamprag">{{cite web|url=http://www.binisaya.com/cebuano/kamprag|title=kamprag|publisher=Binisaya.com}}</ref> It is also commonly known as "bullfrog" in Philippine English.<ref name="dedicatoria">{{cite conference|author1=Ranell Martin M. Dedicatoria|author2=Carmelita M. Rebancos|author3=Leticia E. Afuang|author4=Ma. Victoria O. Espaldon|year=2010|title=Identifying Environmental Changes in Mt. Data Watershed, Bauko, Mt. Province, Northern Philippines: Implications to Sustainable Management |conference= 4th Asian Rural Sociology Association (ARSA) International Conference |pages=402–412 }}</ref>

===Fiji===
The cane toad was introduced into [[Fiji]] to combat insects that infested sugarcane plantations. The introduction of the cane toad to the region was first suggested in 1933, following the successes in Puerto Rico and Hawaiʻi. After considering the possible side effects, the national government of Fiji decided to release the toad in 1953, and 67 specimens were subsequently imported from Hawaiʻi.<ref name="Lever2001p128-129">{{Harvnb|Lever|2001|pages=128–129}}</ref> Once the toads were established, a 1963 study concluded, as the toad's diet included both harmful and beneficial invertebrates, it was considered "economically neutral".<ref name="Hinckley1963p253-259" /> Today, the cane toad can be found on all major islands in Fiji, although they tend to be smaller than their counterparts in other regions.<ref name="Lever2001p130-131">{{Harvnb|Lever|2001|pages=130–131}}</ref>

===New Guinea===
The cane toad was introduced into [[New Guinea]] to control the [[hawk moth]] larvae eating [[sweet potato]] crops.<ref name="ZugLindgremPippet1975p31-50" /> The first release occurred in 1937 using toads imported from Hawaiʻi, with a second release the same year using specimens from the Australian mainland. Evidence suggests a third release in 1938, consisting of toads being used for human [[pregnancy test]]s—many species of toad were found to be effective for this task, and were employed for about 20&nbsp;years after the discovery was announced in 1948.<ref name="Easteall981p103">{{Harvnb|Easteal|1981|page=103}}</ref><ref name="TylerWassersugSmith2007pp6-7">{{Harvnb|Tyler|Wassersug|Smith|2007|pages=6–7}}</ref> Initial reports argued the toads were effective in reducing the levels of [[cutworm]]s and sweet potato yields were thought to be improving.<ref name="Lever2001p118">{{Harvnb|Lever|2001|page=118}}</ref> As a result, these first releases were followed by further distributions across much of the region,<ref name="Lever2001p118" /> although their effectiveness on other crops, such as cabbages, has been questioned; when the toads were released at [[Wau, Papua New Guinea|Wau]], the cabbages provided insufficient shelter and the toads rapidly left the immediate area for the superior shelter offered by the forest.<ref name="Tyler1976pp83-84">{{Harvnb|Tyler|1976|pages=83–84}}</ref> A similar situation had previously arisen in the Australian cane fields, but this experience was either unknown or ignored in New Guinea.<ref name="Tyler1976pp83-84" /> The cane toad has since become abundant in rural and urban areas.<ref name="Lever2001p119">{{Harvnb|Lever|2001|page=119}}</ref>

===United States===
The cane toad naturally exists in [[South Texas]], but attempts (both deliberate and accidental) have been made to introduce the species to other parts of the country. These include introductions to [[Florida]] and to Hawaiʻi, as well as largely unsuccessful introductions to [[Louisiana]].<ref name="Easteal1981pp100-102">{{Harvnb|Easteal|1981|pages=100–102}}</ref>

Initial releases into Florida failed. Attempted introductions before 1936 and 1944, intended to control sugarcane pests, were unsuccessful as the toads failed to proliferate. Later attempts failed in the same way.<ref name="Lever2001p57">{{Harvnb|Lever|2001|page=57}}</ref><ref name="Easteal1981p100">{{Harvnb|Easteal|1981|page=100}}</ref> However, the toad gained a foothold in the state after an accidental release by an importer at [[Miami International Airport]] in 1957, and deliberate releases by animal dealers in 1963 and 1964 established the toad in other parts of Florida.<ref name="Easteal1981p100" /><ref name="Lever2001p58">{{Harvnb|Lever|2001|page=58}}</ref> Today, the cane toad is well established in the state, from the [[Florida Keys|Keys]] to north of [[Tampa, Florida|Tampa]], and they are gradually extending further northward.<ref name="Lever2001p59">{{Harvnb|Lever|2001|page=59}}</ref> In Florida, the toad is a regarded as a threat to native species<ref>{{cite web |url=http://www.wec.ufl.edu/extension/wildlife_info/frogstoads/bufo_marinus.php |title=''Bufo marinus'' @ Florida Wildlife Extension at UF/IFAS |website=Wec.ufl.edu |access-date=2010-04-26}}</ref> and pets;<ref>{{cite web |url=http://www2.tbo.com/content/2007/nov/02/021636/poisonous-bufo-may-have-toad-hold-temple-terrace/ |archive-url=https://archive.today/20130203202720/http://www2.tbo.com/content/2007/nov/02/021636/poisonous-bufo-may-have-toad-hold-temple-terrace/ |archive-date=2013-02-03 |title=Poisonous Bufo May Have Toad Hold On Temple Terrace |publisher=.tbo.com |date=2007-11-02 |access-date=2010-04-26 }}</ref> so much so, the [[Florida Fish and Wildlife Conservation Commission]] recommends residents to kill them.{{sfn|Brandt|Mazzotti|2005}}

Around 150 cane toads were introduced to [[Oʻahu]] in Hawaiʻi in 1932, and the population swelled to 105,517 after 17&nbsp;months.<ref name="Tyler1989p113-114"/> The toads were sent to the other islands, and more than 100,000 toads were distributed by July 1934;<ref name="Lever2001p64">{{Harvnb|Lever|2001|page=64}}</ref> eventually over 600,000 were transported.<ref name="Easteal1981p101">{{Harvnb|Easteal|1981|page=101}}</ref>

==Uses==
[[File:Cane Toad Products.jpg|thumb|upright|Cane toad merchandise|alt=A selection of cane toad merchandise, including key rings made from their legs, a coin purse made from the head, front limbs and body of a toad, and a stuffed cane toad]]

Other than the use as a [[Biological pest control|biological control for pests]], the cane toad has been employed in a number of commercial and noncommercial applications. Traditionally, within the toad's natural range in South America, the [[Embera-Wounaan]] would "milk" the toads for their toxin, which was then employed as an [[arrow poison]]. The toxins may have been used as an [[entheogen]] by the [[Olmecs|Olmec]] people. The toad has been hunted as a food source in parts of [[Peru]], and eaten after the careful removal of the skin and [[parotoid gland]]s.<ref name="Lever2001p32">{{Harvnb|Lever|2001|page=32}}</ref> When properly prepared, the meat of the toad is considered healthy and as a source of [[omega-3 fatty acid]]s.<ref>{{cite web |url=http://www.abc.net.au/news/2014-11-11/academic-wants-us-to-eat-cane-toads/5882986?WT.mc_id=Corp_News-Nov2014 |publisher=ABC |author=Terzon, Emilia|title=Eating cane toads a win-win solution for Australia's environment and stomachs, says academic |date=11 November 2014|access-date=11 November 2014}}</ref>  More recently, the toad's toxins have been used in a number of new ways: [[bufotenin]] has been used in Japan as an [[aphrodisiac]] and a [[Baldness treatments|hair restorer]], and in [[cardiac surgery]] in China to lower the heart rates of patients.<ref name="issgBufoMarinus" /> New research has suggested that the cane toad's poison may have some applications in treating [[prostate cancer]].<ref>{{cite news |url=http://www.abc.net.au/news/2014-09-17/cane-toad-venom-attacks-cancer-cells/5750114 |title=Cane toad poison 'attacks prostate cancer cells' |newspaper=ABC News |date=2014-09-17 |df=dmy-all}}</ref>

Other modern applications of the cane toad include pregnancy testing,<ref name="Lever2001p32" /> as pets,<ref name="Mattison1987p145">{{Harvnb|Mattison|1987|page=145}}</ref> laboratory research,<ref name="Tyler1976p85">{{Harvnb|Tyler|1976|page=85}}</ref> and the production of [[leather]] goods. [[Pregnancy test]]ing was conducted in the mid-20th century by injecting urine from a woman into a male toad's [[Lymphatic system|lymph sacs]], and if [[spermatozoa]] appeared in the toad's urine, the patient was deemed to be pregnant.<ref name="Lever2001p32" /> The tests using toads were faster than [[Rabbit test|those employing mammals]]; the toads were easier to raise, and, although the initial 1948 discovery employed ''[[Bufo arenarum]]'' for the tests, it soon became clear that a variety of [[Frog|anuran]] species were suitable, including the cane toad. As a result, toads were employed in this task for around 20&nbsp;years.<ref name="TylerWassersugSmith2007pp6-7" /> As a [[Animal testing|laboratory animal]], the cane toad has numerous advantages: they are plentiful, and easy and inexpensive to maintain and handle. The use of the cane toad in experiments started in the 1950s, and by the end of the 1960s, large numbers were being collected and exported to high schools and universities.<ref name="Tyler1976p85" /> Since then, a number of Australian states have introduced or tightened importation regulations.<ref name="Tyler1976pp88-89">{{Harvnb|Tyler|1976|pages=88–89}}</ref>

There are several commercial uses for dead cane toads. Cane toad skin is made into leather and novelty items.<ref name="McCarin2008p8">{{Harvnb|McCarin|2008|page=8}}</ref><ref name="Hardie2001p3">{{Harvnb|Hardie|2001|page=3}}</ref> Stuffed cane toads, posed and accessorised, are merchandised at souvenir shops for tourists.<ref name="Bateman2008p48">{{Harvnb|Bateman|2008|page=48}}</ref> Attempts have been made to produce [[fertiliser]] from toad carcasses.<ref name="AAP2006">{{Harvnb|Australian Associated Press|2006}}</ref>

== See also ==
* {{Portal-inline|Frogs}}

==References==
===Citations===
{{Reflist}}

===Bibliography===
{{Refbegin|30em}}
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{{Refend}}

== External links ==
{{Commons category|Rhinella marina}}
{{Wikispecies|Rhinella marina}}
{{Spoken Wikipedia|Cane_Toad.ogg|date=2006-09-19}}
* [https://www.invasivespeciesinfo.gov/aquatic/fish-and-other-vertebrates/cane-toad Species Profile – Cane Toad (''Rhinella marina'')], National Invasive Species Information Center, [[United States National Agricultural Library]]. Lists general information and resources for cane toad.

{{Taxonbar |from=Q321087}}
{{Authority control}}

[[Category:Rhinella]]
[[Category:Animal taxa named by Carl Linnaeus]]
[[Category:Agricultural pests]]
[[Category:Amphibians described in 1758]]
[[Category:Amphibians of Central America]]
[[Category:Amphibians of the Dominican Republic]]
[[Category:Amphibians of Guyana]]
[[Category:Amphibians of Japan]]
[[Category:Amphibians of Mauritius]]
[[Category:Amphibians of New South Wales]]
[[Category:Amphibians of the Northern Territory]]
[[Category:Amphibians of Queensland]]
[[Category:Amphibians of Trinidad and Tobago]]
[[Category:Fauna of Barbados]]
[[Category:Fauna of the Rio Grande valleys]]
[[Category:Frogs of Australia]]
[[Category:Frogs of Brazil]]