Cane toad: Difference between revisions
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{{redirect6|Cane toads|the film|Cane Toads: An Unnatural History|the rugby league team|Queensland state rugby league team}} |
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{{Taxobox |
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| name = Cane toad |
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| status = LC |
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| status_system = IUCN2.3 |
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| trend = up |
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| status_ref =<ref>{{IUCN2006|assessors=Solís ''et al''|year=2004|id=41065|title=Bufo marinus|downloaded=11 May 2006}} Database entry includes a range map and justification for this species is of least concern.</ref> |
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| image = Bufo_marinus_from_Australia.JPG |
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| regnum = [[Animal]]ia |
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| phylum = [[Chordate|Chordata]] |
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| classis = [[Amphibian|Amphibia]] |
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| ordo = [[Anura]] |
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| familia = [[Bufonidae]] |
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| genus = ''[[Bufo]]'' |
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| species = '''''B. marinus''''' |
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| binomial = ''Bufo marinus'' |
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| binomial_authority = ([[Carolus Linnaeus|Linnaeus]], 1758) |
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| range_map = Bufo marinus distribution.png |
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| range_map_caption = Distribution of the cane toad. Native distribution in blue, introduced in red. |
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| synonyms = ''Rhinella marinus''<br><small>Pramuk, Robertson, Sites & Noonan, 2008</small><br>''Chaunus marinus''{{Fact|date=October 2008}} |
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}} |
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[[Image:Cane-toad.jpg|thumb|right|235px|Lightly coloured cane toad]] |
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The '''cane toad''' (''Bufo marinus''), also known as the '''Giant Neotropical Toad''' or '''Marine Toad''', is a large, terrestrial [[true toad]] native to [[Central America|Central]] and [[South America]]. It is a member of the subgenus ''[[Chaunus]]'' of the [[genus]] ''[[Bufo]]'', which includes many different true toad [[species]] throughout Central and South America. The cane toad is a prolific breeder; females lay single-clump [[Spawn (biology)|spawn]]s with large numbers of [[egg (biology)|eggs]]. Its reproductive success is partly because of opportunistic feeding: it has a diet, unusual among [[Anurans]], of both dead and living matter. Adults average 10 to 15 centimetres (4–6 in) in length; the largest recorded specimen weighed 2.65 kg (5.8 lb) with a length of 38 cm (15 in) from snout to vent. |
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The cane toad has [[poison]] [[gland]]s, and the [[tadpole]]s are highly toxic to most animals if ingested. Because of its voracious appetite, the cane toad has been introduced to many regions of the [[Pacific Ocean|Pacific]] and the [[Caribbean]] islands as a method of agricultural [[pest control]], notably failing in the case of [[Australia]] in 1935, and derives its common name from its use against the greyback [[cane beetle]] pests. The cane toad is now considered a pest and [[invasive species]] in many of its introduced regions, because its toxic skin kills many native predators when ingested. It has many negative effects on farmers because of pets and animals eating the creatures. |
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==Taxonomy== |
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The common name of "cane toad" is derived from the original purpose of using it to eradicate pests in sugar cane crops. The cane toad has many other common names, including "Giant Toad" and "Marine Toad"; the former refers to their size, and the latter to the binomial name, ''Bufo marinus''. It was one of the many species originally described by [[Carolus Linnaeus|Linnaeus]] in his 18th century work ''[[Systema Naturae]]''.<ref>{{la icon}} {{cite book | last=Linnaeus | first=C | authorlink=Carolus Linnaeus | title=Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. | publisher=Holmiae. (Laurentii Salvii). | year=1758| pages=824 | url=http://dz1.gdz-cms.de/index.php?id=img&no_cache=1&IDDOC=265100}}</ref> Linnaeus based the [[specific epithet]], ''marinus'', on an illustration by [[Albertus Seba]], who mistakenly believed the cane toad to inhabit both terrestrial and marine environments.<ref> {{cite web| title=Scientific and Common Names of the Reptiles and Amphibians of North America| url=http://ebeltz.net/herps/etymain.html| accessdate=2006-06-05}} </ref> Other common names include "Giant Neotropical Toad," "Dominican Toad," "Giant Marine Toad," and "South American Cane Toad." In [[Trinidad]]ian English they are commonly called "Crapaud" (the French name for "toad"). |
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In Australia, the adults may be confused with species of the ''[[Limnodynastes]]'', ''[[Neobatrachus]]'', ''[[Barred frogs|Mixophyes]]'', and ''[[Notaden]]'' genera. These species can be readily distinguished from the cane toad by the lack of large [[parotoid gland]]s behind their eyes. Cane toads have been confused with the [[Giant Burrowing Frog]] (''Heleioporus australiacus''), because both are large and warty in appearance; however, the Giant Burrowing Frog can be readily distinguished from the cane toad by its vertical pupils. Juvenile cane toads may be confused with species of the ''[[Uperoleia]]'' genus, because they all have large parotoid glands; juvenile cane toads can be distinguished from these species by the ridging around their eyes and the lack of bright colouring on their thighs.<ref> {{cite web| title=Identifying a Cane Toad| url=http://www.nationalparks.nsw.gov.au/npws.nsf/Content/Identifying+a+cane+toad| accessdate=2006-09-07}} </ref> |
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In the [[United States]], the cane toad closely resembles many Bufonid species. In particular, it could be confused with the [[Southern toad]] (''Bufo terrestris'') and [[Fowler's Toad]] (''Bufo fowleri''). The Southern Toad can be distinguished by the presence of two bulbs in front of the parotoid glands, and the Fowler's Toad has a pale, cream-white stripe that runs down the dorsal surface; the cane toad lacks this stripe. |
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It is possible to confuse the cane toad with the [[Rococo Toad]] (''Bufo schneideri''), sometimes referred to as Schneider's Toad, whose range overlaps that of the cane toad. The Rococo Toad grows to nearly the same size but has additional poison glands on its back legs which can be used to reliably identify it. Within its native range, the cane toad can be distinguished from the other true toads by the shape of its parotoid glands and the arrangement of the ridges on its head. |
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==Description== |
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[[Image:Young Bufo marinus.jpg|thumb|200px|A young cane toad ''(Bufo marinus)'']] |
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The cane toad is very large; the females are larger than males, reaching an average length of 10–15 centimetres (4–6 in), and much longer in some cases. "Prinsen", a toad kept as a pet in [[Sweden]], is listed by the ''[[Guinness World Records|Guinness Book of Records]]'' as the largest recorded specimen. It reportedly weighed 2.65 kilograms (5.84 lb) and measured 38 centimetres (15 in) from snout to vent, or 54 centimetres (21 in) when fully extended.<ref> {{cite book| last=Wyse| first=E. (editor)| year=1997| title=Guinness Book of Records 1998| publisher=Guinness Publishing| pages=249| isbn=0-85112-044-X}} </ref> (3 lb).<ref>{{cite book| last=Tyler| first=M. J.| year=1994| title=Australian Frogs A Natural History| publisher=Reed Books| pages=108| isbn=0-7301-0468-0}} </ref> They have a life expectancy of 10 to 15 years in the wild and as long as 20 years in captivity. |
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The skin of the cane toad is dry and warty. It has distinct ridges above the eyes which run down the snout. Cane toads can be grey, brown, red-brown or olive in colour, with varying patterns. A large parotoid gland lies behind each eye. The ventral surface is cream and may have blotches in shades of black or brown. The pupils are horizontal and the irises golden. The toes have a fleshy webbing at their base, and the fingers are free of webbing. |
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Juvenile cane toads are much smaller than adult cane toads—only 5 to 10 centimetres (2–4 in) long. Typically, they have smooth, dark skin, although some specimens have a red wash. Juveniles lack the adults' large parotoid glands, so they are usually less poisonous. Because they lack this key defence, it is estimated that only 0.5% of metamorph Cane toads reach adulthood.<ref> {{cite book| last=Anstis| first=M.| year=2002| title=Tadpoles of South-Eastern Australia: A Guide with Keys| publisher=Reed New Holland| page=274| isbn=1-876334-63-0}} </ref> The tadpoles are small and uniformly black. They are bottom-dwellers and congregate around plants forming [[Swarm|schools]]. Tadpoles reach 27 millimetres (1 in) in length but are smaller—up to 22 millimetres (0.9 in)—under overcrowded conditions. |
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==Ecology, behaviour and life history== |
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Adult Cane Toads possess enlarged parotoid glands behind the eyes and other glands across the back. When threatened, the Cane Toad secretes a milky-white fluid known as [[bufotoxin]] from these glands. Bufotoxin contains components that are toxic to many animals. There are many reported deaths of animals and even reported deaths of humans,<ref>{{cite web|title=issg Database: Ecology of Bufo marinus|url=http://www.issg.org/database/species/ecology.asp?si=113&fr=1&sts=| accessdate=2006-05-16}} </ref> after consumption of Cane Toads. A Cane Toad is capable of inflating its lungs, puffing up and lifting its body off the ground to appear taller and larger to a predator. |
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Most frogs identify prey by their movements; Cane Toads can also locate food using their sense of smell. They are therefore not limited to living prey and can eat plants, carrion, dog food and household refuse apart from the normal frog prey of small [[vertebrate]]s and a range of [[invertebrate]]s. They are active primarily at night and can range far from water. |
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The common name of "Marine Toad", and the scientific name ''Bufo marinus'', suggest a link to [[marine biology|marine life]]; however, there is no such link. Adult cane toads are entirely terrestrial, venturing to fresh water to breed, and tadpoles have been found to only tolerate salt concentrations equivalent to 15% that of sea water.<ref>{{cite journal| last=Ely| first=C.A.| year=1944| title=Development of Bufo marinus larvae in dilute sea water| journal=Copeia| volume=56(4)| pages=256| doi=10.2307/1438692}} </ref> Both eggs and tadpoles are toxic to many animals. This toxic protection remains at all life stages and very young cane toads kill small reptiles that eat them. Cane toads inhabit open grassland and woodland, generally avoiding heavily forested areas; this inhibits their spread in many of the regions in which they were introduced. |
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Many species prey on the cane toad in its native distribution. These include the [[Broad-snouted Caiman]] (''Caiman latirostris''), the [[Banded Cat-eyed Snake]] (''Leptodeira annulata''), the [[Anguillidae|eel]] (family: Anguillidae), various species of [[killifish]], the Rock flagtail (''[[Flagtail|Kuhlia]] [[Kuhlia rupestris|rupestris]]''), some species of [[catfish]] (order: Siluriformes) and some species of [[ibis]] (subfamily: Threskiornithinae). Predators outside the cane toad's native range include the [[Whistling Kite]] (''Haliastur sphenurus''), the [[Rakali]] (''Hydromys chrysogaster''), the [[Black Rat]] (''Rattus rattus'') and the [[Water monitor|Water Monitor]] (''Varanus salvator''). Occasional cases of the [[Tawny Frogmouth]] (''Podargus strigoides'') and the [[Papuan Frogmouth]] (''Podargus papuensis'')<ref>{{cite journal|last=Angus|first=R.|year=1994|title=Observation of a Papuan Frogmouth at Cape York [Queensland]|journal=Aust. Birds.|volume= 28|pages=10–11}}</ref> and [[Acrochordus arafurae|afuran]] snakes (''Acrochordus arafurae'') {{Fact|date=April 2008}} feeding on cane toads have been reported. These predators possess either a tolerance to the cane toad's toxins or behavioural adaptations that allow them to avoid the most poisonous areas of the frog as they hunt and consume it. |
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===Poison=== |
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[[Bufotenin]], one of the chemicals excreted by the cane toad, is classified as a Class 1 drug under Australian drug laws. This is the same classification as [[heroin]] and [[marijuana]]. It is thought that the effects of bufotenin are similar to that of mild poisoning; the stimulating effect, which includes mild hallucinations, lasts for less than one hour.<ref> {{cite web| title=Radar:Really caning it| url=http://radar.smh.com.au/archives/2004/08/really_caning_i.html| accessdate=2006-05-30}} </ref> Since the cane toad excretes bufotenin in very small amounts, and other toxins in relatively large amounts, [[Psychoactive toad|toad licking]] could result in serious illness or death.<ref>{{cite journal| last=Weil| first=A.T.| year=1994| title=Bufo alvarius: a potent hallucinogen of animal origin.| journal=Journal of Ethnopharmacology| volume=41(1–2)| pages=1–8|coauthors=Davis, W.| doi=10.1016/0378-8741(94)90051-5}} </ref> |
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==Distribution== |
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The cane toad is native to the [[Americas]], from the [[Rio Grande Valley]] in southern [[Texas]] to central [[Amazon Basin|Amazon]] and south-eastern [[Peru]]. This range includes both [[Tropics|tropical]] and semi-[[arid]] environments. The density of the cane toad within its native distribution is significantly lower than that of its introduced distribution. In [[South America]], it is recorded at densities of 20 adults per 100 metres of shoreline, but in Australia the density reaches 1,000–2,000 adults over the same area. The cane toad was originally brought to Australia to eat the Cane grub.<ref> {{cite journal| last=Lampo| first=M.| year=1998| title=The Invasion Ecology of the Toad ''Bufo marinus'': from South America to Australia| journal=Ecological Applications| coauthors=De Leo, G.A.| volume=8(2)| pages=288–296}} </ref> |
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===Introductions=== |
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The cane toad has been introduced to many regions of the world, particularly the Pacific, for the biological control of agricultural pests. Up until 1840, cane toads had been introduced into [[Martinique]], [[Barbados]] and [[Jamaica]]. They were unsuccessfully introduced into Jamaica to control the [[rat]] population. |
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In 1920, cane toads were introduced into [[Puerto Rico]] to control the populations of [[Phyllophaga (genus)|white-grub]] (''Phyllophaga'' spp.), a pest of sugar cane. By 1932, the cane toad was well established on the island, and the populations of white-grubs were dramatically decreased. The decrease in the white-grub population was attributed to the cane toad, although there may have been other factors. The six year period after 1931 (when the cane toad was most prolific, and the white-grub saw dramatic decline) recorded the highest ever rainfall for Puerto Rico.<ref>{{cite journal| last=Freeland| first=W.J.| year=1985| title=The Need to Control Cane Toads| journal=Search| volume=16(7–8)| pages=211–215}}</ref> However, the assumption that the cane toad controlled the white-grub led to the large scale introductions throughout many parts of the Pacific. |
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There are introduced populations in Australia, [[Florida]], [[Papua New Guinea]], the [[Philippines]], the [[Ogasawara Islands|Ogasawara]] and [[Ryukyu Islands]] of [[Japan]], most Caribbean islands and many Pacific islands, including [[Hawaii]] and [[Fiji]]. Cane toads were introduced into Fiji to combat insects which infest sugar cane plantations. The introductions generally failed to control the targeted pests, most of which were later controlled by the use of [[insecticide]]s. Since then, the cane toad has become a pest in the host countries, posing a serious threat to native animals. The introduction of the cane toad has had a particularly great effect on Australian [[biodiversity]]. This is probably because of the large number of species that the cane toad successfully competes with and the large areas of open [[grassland]] and open woodland. |
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The cane toad was successfully introduced into New Guinea to control the [[hawk moth]] larvae, which were eating the [[sweet potato]] crops. Cane toads have since become abundant in rural and urban regions and have not penetrated the forested areas; because most of the native wildlife is restricted to forested areas, the cane toad has not caused significant environmental problems. |
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==== Australia ==== |
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The cane toad in [[Australia]] is regarded as an exemplary case of a "[[feral species]]"—others being [[rabbit]]s, [[fox]]es, [[cat]]s, and [[Giant Mimosa]]. Australia's relative isolation prior to [[Europe]]an [[colonisation]] and the [[industrial revolution]]—both of which dramatically increased traffic and importation of novel species—allowed development of a complex, interdepending system of ecology, but one which provided no natural predators for many of the species subsequently introduced. The recent, sudden inundation of foreign species has led to severe breakdowns in Australian [[ecology]], after overwhelming proliferation of a number of [[introduced species]] for which the continent has no efficient natural predator or parasite, and which displace native species—in some cases these species are physically destructive to habitat as well. |
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[[Image:Bufoinvasion.gif|thumb|right|300px|The spread of cane toads in Australia from 1940 to 1980 in 5-year intervals]] |
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Cane toads were introduced to Australia from Hawaii in June 1935 in an attempt to control the native [[Cane Beetle]] (''Dermolepida albohirtum''). They bred immediately in captivity, and by August 1935 more than 3,000 young toads were released in areas around [[Cairns, Queensland|Cairns]], [[Gordonvale, Queensland|Gordonvale]] and [[Innisfail, Queensland|Innisfail]] in northern Queensland. More toads were released around [[Ingham, Queensland|Ingham]], [[Ayr, Queensland|Ayr]], [[Mackay, Queensland|Mackay]] and [[Bundaberg, Queensland|Bundaberg]]. Releases were temporarily limited because of environmental concerns but resumed in other areas after September 1936. Since their release, toads have rapidly multiplied in population and now number over 200 million and have been known to spread diseases affecting local biodiversity.<ref>{{cite web| title= Institute for Molecular Bioscience, Killing off the cane toad| url=http://www.imb.uq.edu.au/index.html?page=48437| accessdate=2006-12-06}}</ref> The toads have steadily expanded their range through Queensland, reaching the border with [[New South Wales]] in 1978 and the [[Northern Territory]] in 1984. The toads on the western frontier of their advance have evolved larger legs;<ref> {{cite web|title=Toxic Toads Evolve Longer Legs, Study Says. 15/02/06. National Geographic News|url=http://news.nationalgeographic.com/news/2006/02/0215_060215_cane_toads.html|accessdate=2006-05-19}} </ref> this is thought to be related to their ability to travel farther. As a consequence of their longer legs, larger bodies, and faster movement, about 10% of the leading edge cane toads have also developed [[arthritis]].<ref>{{cite news |url=http://www.nytimes.com/2007/10/16/science/16obtoad.html?_r=1&adxnnl=1&oref=slogin&pagewanted=all&adxnnlx=1193531451-eJSm5PA39SmnzeZ9ztvwsQ |title=Arthritis Fails to Slow Invading Toads in Australian Fields |author=Henry Fountain |publisher=NY Times |date+October 16, 2007 |accessdate=2007-10-27}}</ref> It is estimated that cane toads migrate at an average of 40 kilometres (25 mi) per year.<ref> {{cite book| last=Tyler| first=M. J.| year=1994| title=Australian Frogs A Natural History| publisher=Reed Books| pages=112| isbn=0-7301-0468-0}} </ref> |
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The long-term impact of toads on the Australian environment is difficult to determine. Precipitous declines in populations of the [[Northern Quoll]] (''Dasyurus hallucatus'') have been observed after toads have invaded an area. There are a number of reports of declines in [[goanna]] and snake populations after the arrival of toads.<ref> {{cite journal | last = Mayes | first = P.J. | title = Diet and foraging behaviour of the semi-aquatic ''Varanus mertensi'' (Reptilia: Varanidae) | url = http://publish.csiro.au/%3Fact%3Dview_file%26file_id%3DWR04040.pdf | journal = Wildlife Research | volume = 32 | pages = 67–74 | year = 2005 | coauthors = Thompson, G. G. and Withers P.C. | doi = 10.1071/WR04040|format=PDF}} </ref> The preliminary risk assessment of cane toads in [[Kakadu National Park]] stated that the predation of the cane toad by native wildlife is the greatest risk to biodiversity. Other factors, such as competition with native wildlife for resources, and the predation of the cane toad on native wildlife, were considered much lower risk factors<ref> {{cite web|title=SSR164 - A preliminary risk assessment of cane toads in Kakadu National Park | url=http://www.deh.gov.au/ssd/publications/ssr/164.html| accessdate=2006-05-22}}</ref> but requiring further study.<ref>{{cite journal|author=Boland, C. R. J.|year=2004|journal=Biological Conservation|volume=120|issue=1|pages=53–62|title=Introduced cane toads Bufo marinus are active nest predators and competitors of rainbow bee-eaters Merops ornatus: observational and experimental evidence}}</ref> In the Northern Territory, goanna predation on cane toads has been linked to a rise in the amount of undamaged [[salt water crocodile]] eggs.<ref> {{cite web|title=Cane toad impact will boost croc hatchling numbers, researchers say | url=http://www.abc.net.au/news/newsitems/200609/s1742950.htm| accessdate=2006-10-15}} </ref> |
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Cane toads were present within a few days of the crocodiles hatching in April, 2007. <ref>{{cite web| title=Cane Toads Present for Croc Hatching| url=http://sbs.discuvery.australia/canetoads.65145.d69f2544a66|}}</ref> |
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Numerous native species have been reported as successfully preying on toads. Some birds, such as the [[Black Kite]] (''Milvus migrans''),<ref> {{cite journal | last = Mitchell | first = D. | title = Predation on the Cane Toad (Bufo marinus) by the black kite (Milvus migrans) | journal = Memoirs - Wueensland Museum | volume = 38 | pages = 512–531 | year = 1995 | coauthors = Jones, A. Hero, J.-M.}} </ref> have learned to attack the toad's belly, avoiding the poison-producing glands on the back of the head. Reports in the Northern Territory suggest that a native frog, [[Dahl's Aquatic Frog]] (''Litoria dahlii''), is able to eat the tadpoles and live young of the toad without being affected by the poison that often kills other predators.<ref> {{cite web|title=NT frog 'eats' Cane Toad. 15/15/2004. ABC News Online| url=http://www.abc.net.au/news/newsitems/200412/s1265310.htm|accessdate=2006-05-09}} </ref> This is believed to account for slower than expected infestations of toads in certain areas of the Northern Territory. Some snakes have been reported to have adapted smaller jaws so that they are unable to swallow large cane toads which have large quantities of poison.<ref> {{cite journal | last = Phillips | first = Ben L. | title = Adapting to an invasive species: Toxic Cane Toads induce morphological change in Australian snakes | url = http://www.pnas.org/cgi/content/abstract/101/49/17150 | doi = 10.1073/pnas.0406440101 <!--Retrieved from url by DOI bot--> | journal = PNAS | volume = 101(49) | pages = 17150–17155 | year = 2004 | month = December| coauthors = and Shine, Richard | pmid = 15569943}} </ref> Another study, however, notes that the cane toad is adapting to a wider environmental range and may in the future be spreading into habitats currently not available.<ref>{{cite journal | last = Urban| first = Mark C. | title = The cane toad's (Chaunus [Bufo] marinus) increasing ability to invade Australia is revealed by a dynamically updated range model | doi = 10.1098/rspb.2007.0114 <!--Retrieved from url by DOI bot--> | journal = Proceedings of the Royal Society B: Biological Sciences | year = 2007 | coauthors = Ben L. Phillips, David K. Skelly, and Richard Shine}} </ref> |
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As of 2005, [[ultraviolet]] light which attracts the moths the toads love has been used to lure and capture Cane Toads for extermination.<ref>{{cite web|title=Northern Australian Frog Database System| url=http://www.frogwatch.org.au/index.cfm?attributes.fuseaction=viewResearch&research_id=141| accessdate=2006-05-20}} </ref> In June 2006, the [[University of Queensland]] announced research into a gene to reverse the sex of female cane toads. This would lead to a population of males, and thus eliminate the population.<ref>{{cite web|title=ABC news online: Gender bending could see cane toad's end|url=http://www.abc.net.au/news/newsitems/200606/s1656274.htm| dateformat=mdy | accessdate=June 18 2007}}</ref> |
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==In popular culture== |
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The introduction and migration of the cane toad in Australia was popularised by the film ''[[Cane Toads: An Unnatural History]] (1988)'', which tells the tale with a humorous edge and is often shown in [[Environmental Science]] courses. [[Don Spencer]], a popular children's entertainer, sang the song "[[Warts 'n' All]]", which was used in the documentary. |
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The toxic skin is regarded by some as a useful [[drug]], and has been smoked to obtain its [[hallucinogen]]ic effects. |
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[[Image:Agarkroete fg4.jpg|thumb|right|300px|A purse made from ''Bufo marinus''.]] |
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In Australia, attempts have been made to make use of dead cane toads, which can number in the thousands and cause hygiene problems. This includes processing the carcasses into liquid fertilisers.<ref> {{cite web| title=Toads as Fertilizer - DirtDoctor.com - Howard Garrett| url=http://www.dirtdoctor.com/view_question.php?id=1470| accessdate=2006-06-07}} </ref> Their skin can be made into leather, and comical cane-toad purses, or coin-purses, retaining the toad fore-body, are sometimes seen (eg see accompanying photo). Cane toads have also been known to be a significant source of food for humans in their native environment; cane toads are cooked by skinning them and taking out the internal organs (including the poisonous glands), and then roasting them. Many people who have eaten cane toads say they are like chicken except with a drier taste.{{Fact|date=February 2009}} |
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In Australian states where the cane toad is common, some rather cruel 'sports' have developed, such as cane toad golf and cane toad cricket, where cane toads are used as balls. In April 2005, [[Dave Tollner]], a Northern Territory [[Australian House of Representatives|Member of Parliament]], called for legalisation of attacking cane toads. This was criticized by many animal and conservation groups who claim freezing is a more humane way to kill cane toads than hitting them with cricket bats.<ref> {{cite web| title=Cane toad clubbing sparks controversy| url=http://www.abc.net.au/news/newsitems/200504/s1342444.htm| accessdate=2006-06-20}} </ref> The short film "[[Cane Toad - What happened to Baz?]]" displays an Australian attitude towards the cane toad. This film won the "Best Comedy" award at the 2003 [[St Kilda Film Festival]]. The film relies on humour which Australians especially connect with, and screenings in overseas festivals have been less well received. {{Fact|date=February 2009}} |
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The cane toad has been listed by the National Trust of Queensland as a state icon of Queensland, alongside the [[Great Barrier Reef]], and past icons, the [[Royal Flying Doctor Service]] and the backyard [[mango]] tree (also an introduced species).<ref> {{cite web| title=National Trust Queensland National Icons| url=http://www.nationaltrustqld.org/qldicons.htm| accessdate=2006-10-17}} </ref> |
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Cane Toad is also a colloquial term for an inhabitant of [[Queensland]], particularly the state's [[Rugby League State of Origin|State of Origin]] football team members and supporters.{{Fact|date=February 2009}} |
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==Notes==<!-- BiolConserv141:1773. --> |
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{{reflist}} |
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==References== |
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*{{cite book| last=Tyler| first=M. J.| year=1994| title=Australian Frogs A Natural History| publisher=Reed Books| isbn=0-7301-0468-0}} |
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*{{cite book| last=Lever| first=C.| year=2001| title=The Cane Toad. The history and ecology of a successful colonist| publisher=Westbury Publishing| isbn=1-84103-006-6}} |
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*{{cite book| last=Barker| first=J.| coauthors=Grigg, G.C.; Tyler, M.J.| year=1995| title=A Field Guide to Australian Frogs| publisher=Surrey Beatty & Sons| isbn=0-949324-61-2}} |
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*{{cite web | title=Cane Toad| url=http://www.honoluluzoo.org/cane_toad.htm| accessdate=2006-05-08 }} |
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*{{cite web | title=Discover Life - Bufonidae: Bufo marinus (Linnaeus, 1758) - Cane toad, Giant toad, Marine toad, Sapo grande | url=http://pick4.pick.uga.edu/mp/20q?search=Bufo+marinus&burl=http://www.invasivespeciesinfo.gov&btxt=InvasiveSpeciesInfo.gov | accessdate=2006-05-18 }} |
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*{{cite web| title=ADW: Bufo marinus: Information| url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Bufo_marinus.html| accessdate=2006-05-23}} |
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*{{cite journal| last=Freeland| first=W.J.| year=1985| title=The Need to Control Cane Toads| journal=Search| volume=16(7–8)| pages=211–215}} |
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*{{cite book| last=Lawson| first=Walter J.| year=1987| title=The Cane Toad, Bufo marinus: A Bibliography (AES working paper)| publisher=School of Australian Environmental Studies, Griffith University| isbn=0-86857-247-0}} |
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*{{cite web | title=He who walks behind the rows - Bufonidae: Bufo marinus (Linnaeus, 1758) - Cane toad, Giant toad, Marine toad, Sapo grande | url =http://images.google.com/imgres?imgurl=http://www.cs.brown.edu/~bjm/images/cotc_big.jpg&imgrefurl=http://www.cs.brown.edu/~bjm/production.htm&h=239&w=455&sz=26&hl=en&start=4&tbnid=WtmFh1-A2XFarM:&tbnh=67&tbnw=128&prev=/images%3Fq%3Dchildren%2Bof%2Bthe%2Bcorn%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG}} |
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*{{cite journal | last = Frost | first = Darrel | year = 2006 | title = The Amphibian Tree of Life | journal = Bulletin of the American Museum of Natural History | volume = 297 | issue = | pages = 364 | doi = 10.1206/0003-0090(2006)297[0001:TATOL]2.0.CO;2}} |
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* {{aut|Pauly, G. B., D. M. Hillis, and D. C. Cannatella.}} (2004) The history of a Nearctic colonization: Molecular phylogenetics and biogeography of the Nearctic toads (''Bufo''). ''Evolution'' ''58'': 2517–2535. |
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== External links == |
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{{sisterlinks|wikt=no|b=no|q=no|s=no|commons=Bufo marinus|n=no|v=no|species=Rhinella marina}} |
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{{Spoken Wikipedia|Cane_Toad.ogg|2006-09-19}} |
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*[http://www.bbc.co.uk/dna/h2g2/A12945017 The Cane Toad - Australia's Amphibian Plague at h2g2] |
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*[http://www.amonline.net.au/factsheets/canetoad.htm Cane Toad factsheet - Australian Museum] |
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*[http://www.jonco48.com/blog/CaneToad2_20_28Medium_29.jpg A picture of a man holding a cane toad] |
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*[http://www.bitte-downloaden.de/animationen/cane_toad.htm "Cane Toad - What Happened To Baz?", the prize-winning Australian animated short, hosted on a German site] |
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*[http://www.invasivespeciesinfo.gov/animals/canetoad.shtml Species Profile - Cane Toad (''Bufo marinus'')], National Invasive Species Information Center, [[United States National Agricultural Library|National Agricultural Library]]. Lists general information and resources for cane toad. |
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[[Category:Toads]] |
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[[Category:Fauna of Argentina]] |
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[[Category:Fauna of Guyana]] |
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[[Category:Fauna of Trinidad and Tobago]] |
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[[Category:Invasive animal species]] |
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[[Category:Amphibians of Queensland]] |
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[[Category:Amphibians of New South Wales]] |
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[[Category:Amphibians of the Northern Territory]] |
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[[Category:Agricultural pests]] |
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Revision as of 03:32, 5 March 2009
| Cane toad | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | |
| Genus: | |
| Species: | B. marinus
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| Binomial name | |
| Bufo marinus (Linnaeus, 1758)
| |
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| Distribution of the cane toad. Native distribution in blue, introduced in red. | |
| Synonyms | |
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Rhinella marinus | |
The cane toad (Bufo marinus), also known as the Giant Neotropical Toad or Marine Toad, is a large, terrestrial true toad native to Central and South America. It is a member of the subgenus Chaunus of the genus Bufo, which includes many different true toad species throughout Central and South America. The cane toad is a prolific breeder; females lay single-clump spawns with large numbers of eggs. Its reproductive success is partly because of opportunistic feeding: it has a diet, unusual among Anurans, of both dead and living matter. Adults average 10 to 15 centimetres (4–6 in) in length; the largest recorded specimen weighed 2.65 kg (5.8 lb) with a length of 38 cm (15 in) from snout to vent.
The cane toad has poison glands, and the tadpoles are highly toxic to most animals if ingested. 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, notably failing in the case of Australia in 1935, and derives its common name from its use against the greyback cane beetle pests. The cane toad is now considered a pest and invasive species in many of its introduced regions, because its toxic skin kills many native predators when ingested. It has many negative effects on farmers because of pets and animals eating the creatures.
Taxonomy
The common name of "cane toad" is derived from the original purpose of using it to eradicate pests in sugar cane crops. The cane toad has many other common names, including "Giant Toad" and "Marine Toad"; the former refers to their size, and the latter to the binomial name, Bufo marinus. It was one of the many species originally described by Linnaeus in his 18th century work Systema Naturae.[2] Linnaeus based the specific epithet, marinus, on an illustration by Albertus Seba, who mistakenly believed the cane toad to inhabit both terrestrial and marine environments.[3] Other common names include "Giant Neotropical Toad," "Dominican Toad," "Giant Marine Toad," and "South American Cane Toad." In Trinidadian English they are commonly called "Crapaud" (the French name for "toad").
In Australia, the adults may be confused with species of the Limnodynastes, Neobatrachus, Mixophyes, and Notaden genera. These species can be readily distinguished from the cane toad by the lack of large parotoid glands behind their eyes. Cane toads have been confused with the Giant Burrowing Frog (Heleioporus australiacus), because both are large and warty in appearance; however, the Giant Burrowing Frog can be readily distinguished from the cane toad by its vertical pupils. Juvenile cane toads may be confused with species of the Uperoleia genus, because they all have large parotoid glands; juvenile cane toads can be distinguished from these species by the ridging around their eyes and the lack of bright colouring on their thighs.[4]
In the United States, the cane toad closely resembles many Bufonid species. In particular, it could be confused with the Southern toad (Bufo terrestris) and Fowler's Toad (Bufo fowleri). The Southern Toad can be distinguished by the presence of two bulbs in front of the parotoid glands, and the Fowler's Toad has a pale, cream-white stripe that runs down the dorsal surface; the cane toad lacks this stripe.
It is possible to confuse the cane toad with the Rococo Toad (Bufo schneideri), sometimes referred to as Schneider's Toad, whose range overlaps that of the cane toad. The Rococo Toad grows to nearly the same size but has additional poison glands on its back legs which can be used to reliably identify it. Within its native range, the cane toad can be distinguished from the other true toads by the shape of its parotoid glands and the arrangement of the ridges on its head.
Description
The cane toad is very large; the females are larger than males, reaching an average length of 10–15 centimetres (4–6 in), and much longer in some cases. "Prinsen", a toad kept as a pet in Sweden, is listed by the Guinness Book of Records as the largest recorded specimen. It reportedly weighed 2.65 kilograms (5.84 lb) and measured 38 centimetres (15 in) from snout to vent, or 54 centimetres (21 in) when fully extended.[5] (3 lb).[6] They have a life expectancy of 10 to 15 years in the wild and as long as 20 years in captivity.
The skin of the cane toad is dry and warty. It has distinct ridges above the eyes which run down the snout. Cane toads can be grey, brown, red-brown or olive in colour, with varying patterns. A large parotoid gland lies behind each eye. The ventral surface is cream and may have blotches in shades of black or brown. The pupils are horizontal and the irises golden. The toes have a fleshy webbing at their base, and the fingers are free of webbing.
Juvenile cane toads are much smaller than adult cane toads—only 5 to 10 centimetres (2–4 in) long. Typically, they have smooth, dark skin, although some specimens have a red wash. Juveniles lack the adults' large parotoid glands, so they are usually less poisonous. Because they lack this key defence, it is estimated that only 0.5% of metamorph Cane toads reach adulthood.[7] The tadpoles are small and uniformly black. They are bottom-dwellers and congregate around plants forming schools. Tadpoles reach 27 millimetres (1 in) in length but are smaller—up to 22 millimetres (0.9 in)—under overcrowded conditions.
Ecology, behaviour and life history
Adult Cane Toads possess enlarged parotoid glands behind the eyes and other glands across the back. When threatened, the Cane Toad secretes a milky-white fluid known as bufotoxin from these glands. Bufotoxin contains components that are toxic to many animals. There are many reported deaths of animals and even reported deaths of humans,[8] after consumption of Cane Toads. A Cane Toad is capable of inflating its lungs, puffing up and lifting its body off the ground to appear taller and larger to a predator.
Most frogs identify prey by their movements; Cane Toads can also locate food using their sense of smell. They are therefore not limited to living prey and can eat plants, carrion, dog food and household refuse apart from the normal frog prey of small vertebrates and a range of invertebrates. They are active primarily at night and can range far from water.
The common name of "Marine Toad", and the scientific name Bufo marinus, suggest a link to marine life; however, there is no such link. Adult cane toads are entirely terrestrial, venturing to fresh water to breed, and tadpoles have been found to only tolerate salt concentrations equivalent to 15% that of sea water.[9] Both eggs and tadpoles are toxic to many animals. This toxic protection remains at all life stages and very young cane toads kill small reptiles that eat them. Cane toads inhabit open grassland and woodland, generally avoiding heavily forested areas; this inhibits their spread in many of the regions in which they were introduced.
Many species prey on the cane toad in its native distribution. These include the Broad-snouted Caiman (Caiman latirostris), the Banded Cat-eyed Snake (Leptodeira annulata), the eel (family: Anguillidae), various species of killifish, the Rock flagtail (Kuhlia rupestris), some species of catfish (order: Siluriformes) and some species of ibis (subfamily: Threskiornithinae). Predators outside the cane toad's native range include the Whistling Kite (Haliastur sphenurus), the Rakali (Hydromys chrysogaster), the Black Rat (Rattus rattus) and the Water Monitor (Varanus salvator). Occasional cases of the Tawny Frogmouth (Podargus strigoides) and the Papuan Frogmouth (Podargus papuensis)[10] and afuran snakes (Acrochordus arafurae) [citation needed] feeding on cane toads have been reported. These predators possess either a tolerance to the cane toad's toxins or behavioural adaptations that allow them to avoid the most poisonous areas of the frog as they hunt and consume it.
Poison
Bufotenin, one of the chemicals excreted by the cane toad, is classified as a Class 1 drug under Australian drug laws. This is the same classification as heroin and marijuana. It is thought that the effects of bufotenin are similar to that of mild poisoning; the stimulating effect, which includes mild hallucinations, lasts for less than one hour.[11] Since the cane toad excretes bufotenin in very small amounts, and other toxins in relatively large amounts, toad licking could result in serious illness or death.[12]
Distribution
The cane toad is native to the Americas, from the Rio Grande Valley in southern Texas to central Amazon and south-eastern Peru. This range includes both tropical and semi-arid environments. The density of the cane toad within its native distribution is significantly lower than that of its introduced distribution. In South America, it is recorded at densities of 20 adults per 100 metres of shoreline, but in Australia the density reaches 1,000–2,000 adults over the same area. The cane toad was originally brought to Australia to eat the Cane grub.[13]
Introductions
The cane toad has been introduced to many regions of the world, particularly the Pacific, for the biological control of agricultural pests. Up until 1840, cane toads had been introduced into Martinique, Barbados and Jamaica. They were unsuccessfully introduced into Jamaica to control the rat population.
In 1920, cane toads were introduced into Puerto Rico to control the populations of white-grub (Phyllophaga spp.), a pest of sugar cane. By 1932, the cane toad was well established on the island, and the populations of white-grubs were dramatically decreased. The decrease in the white-grub population was attributed to the cane toad, although there may have been other factors. The six year period after 1931 (when the cane toad was most prolific, and the white-grub saw dramatic decline) recorded the highest ever rainfall for Puerto Rico.[14] However, the assumption that the cane toad controlled the white-grub led to the large scale introductions throughout many parts of the Pacific.
There are introduced populations in Australia, Florida, Papua New Guinea, the Philippines, the Ogasawara and Ryukyu Islands of Japan, most Caribbean islands and many Pacific islands, including Hawaii and Fiji. Cane toads were introduced into Fiji to combat insects which infest sugar cane plantations. The introductions generally failed to control the targeted pests, most of which were later controlled by the use of insecticides. Since then, the cane toad has become a pest in the host countries, posing a serious threat to native animals. The introduction of the cane toad has had a particularly great effect on Australian biodiversity. This is probably because of the large number of species that the cane toad successfully competes with and the large areas of open grassland and open woodland.
The cane toad was successfully introduced into New Guinea to control the hawk moth larvae, which were eating the sweet potato crops. Cane toads have since become abundant in rural and urban regions and have not penetrated the forested areas; because most of the native wildlife is restricted to forested areas, the cane toad has not caused significant environmental problems.
Australia
The cane toad in Australia is regarded as an exemplary case of a "feral species"—others being rabbits, foxes, cats, and Giant Mimosa. Australia's relative isolation prior to European colonisation and the industrial revolution—both of which dramatically increased traffic and importation of novel species—allowed development of a complex, interdepending system of ecology, but one which provided no natural predators for many of the species subsequently introduced. The recent, sudden inundation of foreign species has led to severe breakdowns in Australian ecology, after overwhelming proliferation of a number of introduced species for which the continent has no efficient natural predator or parasite, and which displace native species—in some cases these species are physically destructive to habitat as well.
Cane toads were introduced to Australia from Hawaii in June 1935 in an attempt to control the native Cane Beetle (Dermolepida albohirtum). They bred immediately in captivity, and by August 1935 more than 3,000 young toads were released in areas around Cairns, Gordonvale and Innisfail in northern Queensland. More toads were released around Ingham, Ayr, Mackay and Bundaberg. Releases were temporarily limited because of environmental concerns but resumed in other areas after September 1936. Since their release, toads have rapidly multiplied in population and now number over 200 million and have been known to spread diseases affecting local biodiversity.[15] The toads have steadily expanded their range through Queensland, reaching the border with New South Wales in 1978 and the Northern Territory in 1984. The toads on the western frontier of their advance have evolved larger legs;[16] this is thought to be related to their ability to travel farther. As a consequence of their longer legs, larger bodies, and faster movement, about 10% of the leading edge cane toads have also developed arthritis.[17] It is estimated that cane toads migrate at an average of 40 kilometres (25 mi) per year.[18]
The long-term impact of toads on the Australian environment is difficult to determine. Precipitous declines in populations of the Northern Quoll (Dasyurus hallucatus) have been observed after toads have invaded an area. There are a number of reports of declines in goanna and snake populations after the arrival of toads.[19] The preliminary risk assessment of cane toads in Kakadu National Park stated that the predation of the cane toad by native wildlife is the greatest risk to biodiversity. Other factors, such as competition with native wildlife for resources, and the predation of the cane toad on native wildlife, were considered much lower risk factors[20] but requiring further study.[21] In the Northern Territory, goanna predation on cane toads has been linked to a rise in the amount of undamaged salt water crocodile eggs.[22] Cane toads were present within a few days of the crocodiles hatching in April, 2007. [23]
Numerous native species have been reported as successfully preying on toads. Some birds, such as the Black Kite (Milvus migrans),[24] have learned to attack the toad's belly, avoiding the poison-producing glands on the back of the head. Reports in the Northern Territory suggest that a native frog, Dahl's Aquatic Frog (Litoria dahlii), is able to eat the tadpoles and live young of the toad without being affected by the poison that often kills other predators.[25] This is believed to account for slower than expected infestations of toads in certain areas of the Northern Territory. Some snakes have been reported to have adapted smaller jaws so that they are unable to swallow large cane toads which have large quantities of poison.[26] Another study, however, notes that the cane toad is adapting to a wider environmental range and may in the future be spreading into habitats currently not available.[27]
As of 2005, ultraviolet light which attracts the moths the toads love has been used to lure and capture Cane Toads for extermination.[28] In June 2006, the University of Queensland announced research into a gene to reverse the sex of female cane toads. This would lead to a population of males, and thus eliminate the population.[29]
In popular culture
The introduction and migration of the cane toad in Australia was popularised by the film Cane Toads: An Unnatural History (1988), which tells the tale with a humorous edge and is often shown in Environmental Science courses. Don Spencer, a popular children's entertainer, sang the song "Warts 'n' All", which was used in the documentary.
The toxic skin is regarded by some as a useful drug, and has been smoked to obtain its hallucinogenic effects.
In Australia, attempts have been made to make use of dead cane toads, which can number in the thousands and cause hygiene problems. This includes processing the carcasses into liquid fertilisers.[30] Their skin can be made into leather, and comical cane-toad purses, or coin-purses, retaining the toad fore-body, are sometimes seen (eg see accompanying photo). Cane toads have also been known to be a significant source of food for humans in their native environment; cane toads are cooked by skinning them and taking out the internal organs (including the poisonous glands), and then roasting them. Many people who have eaten cane toads say they are like chicken except with a drier taste.[citation needed]
In Australian states where the cane toad is common, some rather cruel 'sports' have developed, such as cane toad golf and cane toad cricket, where cane toads are used as balls. In April 2005, Dave Tollner, a Northern Territory Member of Parliament, called for legalisation of attacking cane toads. This was criticized by many animal and conservation groups who claim freezing is a more humane way to kill cane toads than hitting them with cricket bats.[31] The short film "Cane Toad - What happened to Baz?" displays an Australian attitude towards the cane toad. This film won the "Best Comedy" award at the 2003 St Kilda Film Festival. The film relies on humour which Australians especially connect with, and screenings in overseas festivals have been less well received. [citation needed]
The cane toad has been listed by the National Trust of Queensland as a state icon of Queensland, alongside the Great Barrier Reef, and past icons, the Royal Flying Doctor Service and the backyard mango tree (also an introduced species).[32]
Cane Toad is also a colloquial term for an inhabitant of Queensland, particularly the state's State of Origin football team members and supporters.[citation needed]
Notes
- ^ Template:IUCN2006 Database entry includes a range map and justification for this species is of least concern.
- ^ Template:La icon Linnaeus, C (1758). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Holmiae. (Laurentii Salvii). p. 824.
- ^ "Scientific and Common Names of the Reptiles and Amphibians of North America". Retrieved 2006-06-05.
- ^ "Identifying a Cane Toad". Retrieved 2006-09-07.
- ^ Wyse, E. (editor) (1997). Guinness Book of Records 1998. Guinness Publishing. p. 249. ISBN 0-85112-044-X.
{{cite book}}:|first=has generic name (help) - ^ Tyler, M. J. (1994). Australian Frogs A Natural History. Reed Books. p. 108. ISBN 0-7301-0468-0.
- ^ Anstis, M. (2002). Tadpoles of South-Eastern Australia: A Guide with Keys. Reed New Holland. p. 274. ISBN 1-876334-63-0.
- ^ "issg Database: Ecology of Bufo marinus". Retrieved 2006-05-16.
- ^ Ely, C.A. (1944). "Development of Bufo marinus larvae in dilute sea water". Copeia. 56(4): 256. doi:10.2307/1438692.
- ^ Angus, R. (1994). "Observation of a Papuan Frogmouth at Cape York [Queensland]". Aust. Birds. 28: 10–11.
- ^ "Radar:Really caning it". Retrieved 2006-05-30.
- ^ Weil, A.T. (1994). "Bufo alvarius: a potent hallucinogen of animal origin". Journal of Ethnopharmacology. 41(1–2): 1–8. doi:10.1016/0378-8741(94)90051-5.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Lampo, M. (1998). "The Invasion Ecology of the Toad Bufo marinus: from South America to Australia". Ecological Applications. 8(2): 288–296.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Freeland, W.J. (1985). "The Need to Control Cane Toads". Search. 16(7–8): 211–215.
- ^ "Institute for Molecular Bioscience, Killing off the cane toad". Retrieved 2006-12-06.
- ^ "Toxic Toads Evolve Longer Legs, Study Says. 15/02/06. National Geographic News". Retrieved 2006-05-19.
- ^ Henry Fountain. "Arthritis Fails to Slow Invading Toads in Australian Fields". NY Times. Retrieved 2007-10-27.
{{cite news}}: Text "date+October 16, 2007" ignored (help) - ^ Tyler, M. J. (1994). Australian Frogs A Natural History. Reed Books. p. 112. ISBN 0-7301-0468-0.
- ^ Mayes, P.J. (2005). "Diet and foraging behaviour of the semi-aquatic Varanus mertensi (Reptilia: Varanidae)" (PDF). Wildlife Research. 32: 67–74. doi:10.1071/WR04040.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ "SSR164 - A preliminary risk assessment of cane toads in Kakadu National Park". Retrieved 2006-05-22.
- ^ Boland, C. R. J. (2004). "Introduced cane toads Bufo marinus are active nest predators and competitors of rainbow bee-eaters Merops ornatus: observational and experimental evidence". Biological Conservation. 120 (1): 53–62.
- ^ "Cane toad impact will boost croc hatchling numbers, researchers say". Retrieved 2006-10-15.
- ^ "Cane Toads Present for Croc Hatching".
{{cite web}}: Cite has empty unknown parameter:|1=(help) - ^ Mitchell, D. (1995). "Predation on the Cane Toad (Bufo marinus) by the black kite (Milvus migrans)". Memoirs - Wueensland Museum. 38: 512–531.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ "NT frog 'eats' Cane Toad. 15/15/2004. ABC News Online". Retrieved 2006-05-09.
- ^ Phillips, Ben L. (2004). "Adapting to an invasive species: Toxic Cane Toads induce morphological change in Australian snakes". PNAS. 101(49): 17150–17155. doi:10.1073/pnas.0406440101. PMID 15569943.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Urban, Mark C. (2007). "The cane toad's (Chaunus [Bufo] marinus) increasing ability to invade Australia is revealed by a dynamically updated range model". Proceedings of the Royal Society B: Biological Sciences. doi:10.1098/rspb.2007.0114.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ "Northern Australian Frog Database System". Retrieved 2006-05-20.
- ^ "ABC news online: Gender bending could see cane toad's end". Retrieved June 18 2007.
{{cite web}}: Check date values in:|accessdate=(help); Unknown parameter|dateformat=ignored (help) - ^ "Toads as Fertilizer - DirtDoctor.com - Howard Garrett". Retrieved 2006-06-07.
- ^ "Cane toad clubbing sparks controversy". Retrieved 2006-06-20.
- ^ "National Trust Queensland National Icons". Retrieved 2006-10-17.
References
- Tyler, M. J. (1994). Australian Frogs A Natural History. Reed Books. ISBN 0-7301-0468-0.
- Lever, C. (2001). The Cane Toad. The history and ecology of a successful colonist. Westbury Publishing. ISBN 1-84103-006-6.
- Barker, J. (1995). A Field Guide to Australian Frogs. Surrey Beatty & Sons. ISBN 0-949324-61-2.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - "Cane Toad". Retrieved 2006-05-08.
- "Discover Life - Bufonidae: Bufo marinus (Linnaeus, 1758) - Cane toad, Giant toad, Marine toad, Sapo grande". Retrieved 2006-05-18.
- "ADW: Bufo marinus: Information". Retrieved 2006-05-23.
- Freeland, W.J. (1985). "The Need to Control Cane Toads". Search. 16(7–8): 211–215.
- Lawson, Walter J. (1987). The Cane Toad, Bufo marinus: A Bibliography (AES working paper). School of Australian Environmental Studies, Griffith University. ISBN 0-86857-247-0.
- "He who walks behind the rows - Bufonidae: Bufo marinus (Linnaeus, 1758) - Cane toad, Giant toad, Marine toad, Sapo grande".
- Frost, Darrel (2006). "The Amphibian Tree of Life". Bulletin of the American Museum of Natural History. 297: 364. doi:10.1206/0003-0090(2006)297[0001:TATOL]2.0.CO;2.
- Pauly, G. B., D. M. Hillis, and D. C. Cannatella. (2004) The history of a Nearctic colonization: Molecular phylogenetics and biogeography of the Nearctic toads (Bufo). Evolution 58: 2517–2535.
External links
- The Cane Toad - Australia's Amphibian Plague at h2g2
- Cane Toad factsheet - Australian Museum
- A picture of a man holding a cane toad
- "Cane Toad - What Happened To Baz?", the prize-winning Australian animated short, hosted on a German site
- Species Profile - Cane Toad (Bufo marinus), National Invasive Species Information Center, National Agricultural Library. Lists general information and resources for cane toad.
