Editing Goanna

{{short description|Several species of reptiles}}
{{Other uses}}

{{Use dmy dates|date=June 2020}}
[[File:Streifenschwanzwaran (Varanus caudolineatus).jpg|thumb|right|250px|Stripe-tailed goanna (''Varanus caudolineatus'')]]
A '''goanna''' is any one of several [[species]] of lizard of the genus ''[[Monitor lizard|Varanus]]'' found in Australia and Southeast Asia.

Around 70 species of ''Varanus'' are known, 25 of which are found in Australia. This varied group of [[carnivorous]] [[reptile]]s ranges<!--'Group' is the subject, not 'reptiles'.--> greatly in size and fills several [[ecological niche]]s.<ref>Ehmann, Harald. ''Encyclopedia of Australian Animals: Reptiles''. (1992), p. 144. Angus&Robertson, Pymble, Australia. {{ISBN|0-207-17379-6}}.</ref>

The goanna features prominently in [[Dreamtime|Aboriginal mythology]] and [[Australian folklore]].

Being [[predatory]] lizards, goannas are often quite large with sharp teeth and claws. The largest is the [[perentie]] (''V. giganteus''), which can grow over {{convert|2.5|m|ft|abbr=on}} in length. Not all goannas are so large; pygmy goannas may be smaller than the arm of an adult human. The smallest of these, the [[short-tailed monitor]] (''V. brevicauda''), reaches only {{convert|20|cm|in|0|abbr=on}} in length. They survive on smaller prey, such as insects and mice.

Goannas combine predatory and scavenging behaviours. They prey on any animal they can catch that is small enough to eat whole. They have been blamed by farmers for the death of [[sheep]], though most likely erroneously, as goannas are also eaters of [[carrion]] and are attracted to rotting meat.

Most goannas are dark-coloured, with greys, browns, blacks, and greens featuring prominently; however, white is also common. Many desert-dwelling species also feature yellow-red tones. [[Camouflage]] ranges from bands and stripes to splotches, speckles, and circles, and can change as the creature matures, with juveniles sometimes being brighter than adults.

Like most lizards, goannas lay [[egg (biology)|eggs]]. Most lay eggs in a nest or burrow, but some species lay their eggs inside [[termite]] mounds. This offers protection and incubation; additionally, the termites may provide a meal for the young as they hatch. Unlike some other species of lizards, goannas do not have the ability to [[regeneration (biology)|regrow]] limbs or tails.

==Etymology==
The name ''goanna'' is derived from [[iguana|''iguana'']]. Early European bush settlers in Australia likened goannas to the South American lizards.<ref>{{cite news |url=http://nla.gov.au/nla.news-article1591315 |last1=MacDonald |first1=Donald |title=Nature Notes and Queries: Goanna or Iguana |newspaper=[[The Argus (Melbourne)]] |issue=21,990 |location=Victoria, Australia |date=19 January 1917 |access-date=8 November 2018 |page=5 |via=National Library of Australia}}</ref> Over time, the initial vowel sound was dropped. A similar explanation is used to link [[Phalangeriformes|possum]]s to the American [[opossum]].

The South African term for a monitor lizard is ''[[leguaan]]'' and this word is also from Spanish 'la iguana'.{{Citation needed|date=November 2018}}

==Species==
[[File:Varanus varius1.jpg|thumb|right|A [[lace monitor]] (''V. varius'') in [[Byfield National Park]]]]
For a list of all monitor lizards of the genus, see [[Monitor lizard#Taxonomy|Complete list of genus ''Varanus'']].
The following are found in Australia. For the most part, in common names, "goanna" and "monitor" are interchangeable.
*[[Perentie]] &ndash; ''V. giganteus''
*[[Lace monitor]] &ndash; ''V. varius''
*[[Sand goanna]] &ndash; ''V. gouldii'' (also Gould's goanna or ground goanna)
*[[Mertens' water monitor]] &ndash; ''V. mertensi''
*[[Spiny-tailed monitor]] &ndash; ''V. acanthurus'' (also ridge-tailed monitor)
*[[Mangrove monitor]] &ndash; ''V. semiremex''
*[[Black-headed monitor]] &ndash; ''V. tristis''
*[[Short-tailed monitor]] &ndash; ''V. brevicauda''
*[[Argus monitor]] &ndash; ''V. panoptes'' (also yellow-spotted monitor)
*[[Rosenberg's monitor]] &ndash; ''V. rosenbergi''
*[[Spencer's goanna]] &ndash; ''V. spenceri''
*[[Storr's monitor]] &ndash; ''V. storri''
*[[Dampier Peninsula monitor]] &ndash; ''V. sparnus''
*[[Mitchell's water monitor]] &ndash; ''V. mitchelli''
*[[Kings' monitor]] &ndash; ''V. kingorum''
*[[Southern Pilbara rock goanna]] &ndash; ''V. hamersleyensis''
*[[Black-palmed rock monitor]] &ndash; ''V. glebopalma''
*[[Kimberley rock monitor]] &ndash; ''V. glauerti''
*[[Pygmy mulga monitor]] &ndash; ''V. gilleni''
*[[Rusty desert monitor]] &ndash; ''V. eremius''
*[[Stripe-tailed goanna]] &ndash; ''V. caudolineatus''
*[[Pilbara monitor]] &ndash; ''V. bushi''
*[[Black-spotted ridge-tailed monitor]] &ndash; ''V. baritji''
*[[Emerald tree monitor]] &ndash; ''V. prasinus''
*[[Canopy goanna]] &ndash; ''V. keithhornei''

==Habitats==
[[File:Goanna South Australia.jpg|thumb|right|Heath goanna (''Varanus rosenbergii''), [[Kangaroo Island]], [[South Australia]]]]
Goannas are found throughout most of Australia, except for [[Tasmania]], and manage to persist in a variety of environments. Most species are known to climb trees or outcrops; several primarily [[arboreal]] species are known. The [[lace monitor]] (''V. varius'') is probably the best-known among these, but is not the most common. The lace monitor is the second-largest of all goannas, reaching lengths up to {{convert|2|m|ft|abbr=on}}. Other more common tree goannas, such as the [[Timor tree monitor]] (''V. timorensis'') and [[mournful tree monitor]] (''V. tristis'',) do not grow to quite such lengths, typically a maximum of 61&nbsp;cm, nose-to-tail.

Other goannas are adapted to swampy coastal environments, such as the [[mangrove goanna]] (''V. semiremex''). Further still,  [[Mertens' water monitor]] (water goanna &ndash; ''V. mertensi''), found in lagoons and rivers across northern Australia, is streamlined for swimming, using its tail as a paddle. Most other goannas are good swimmers, but tend not to voluntarily venture into water.

==Diet==
The diets of goannas vary greatly depending on the species and the habitat. Prey can include all manner of small animals: insects, smaller lizards, snakes, mammals, birds, and eggs.

Meals are often eaten whole, thus the size of their meals may depend on the size of the animals. Many of the small species feed mostly on insects, with some being small lizard experts. Many of the medium to large species feed on whatever prey they can catch. This includes eggs, fish (''V. mertensi''), birds, snails, smaller lizards, snakes, marsupials, and other small mammals, such as rodents. The giant perentie has been observed killing a young [[kangaroo]], and then biting out chunks of flesh like a dog.

All species are carrion eaters, so feed on the carcasses of dead animals, including livestock and other large creatures.<ref>{{cite book|last=Cogger|first=Harold|title=Australian reptiles in colour|year=1978|publisher=Reed|location=Terrey Hills, N.S.W.|isbn=0-589-50060-0|page=59}}</ref><ref>{{cite book|last=Andrew|first=Learmonth|title=Encyclopaedia of Australia|year=1973|publisher=F. Warne|location=London|isbn=0-7232-1709-2|edition=[2d ed.]|author2=Learmonth, Nancy|page=229}}</ref> The smell of rotting meat also attracts these lizards.{{Citation needed|date=July 2011}}

==Goannas and humans==
[[File:Lace-Monitor-Mount-Coot-tha-1.JPG|thumb|right|250px|A goanna at Grey Gum picnic area at [[Mount Coot-tha, Queensland|Mount Coot-tha]], Queensland, Australia]]

===Confrontations===
Like most native fauna, goannas are rather wary of human intrusions into their habitat, and most likely run away (into the scrub, up a tree, or into the water, depending on the species). A goanna is a rather swift mover, and when pressed, sprints short distances on its hind legs.

Goannas also rear up when threatened, either chased or cornered, and also inflate flaps of skin around their throats and emit harsh hissing noises.

Some goannas lose their initial fear of humans, especially when food is involved (or has been previously involved). The wildlife authority recommends not feeding animals while in their territory. An attack can cause serious injury in exceptional cases,<ref>{{cite web |url=https://www.theguardian.com/australia-news/2019/aug/16/goanna-attack-dog-killed-and-queensland-couple-in-hospital-after-freak-ordeal |title=Goanna attack: Queensland couple in hospital after 'freak ordeal' |newspaper=The Guardian|author=Naaman Zhou |date= 16 August 2019}}</ref> but most authorities doubt that a goanna will direct an intentional attack at a human unless the human has attempted to attack it (or grasp at it) first. [[Indigenous Australians]] who hunt goannas for food consider the perentie to be a high-risk (but tasty) quarry.

Debate is growing as to whether goannas are venomous. The incessant bleeding caused by goanna bites had been thought to be the result of [[septicemia|bacterial infection]], but a 2005 study<ref>{{cite web |url=https://www.newscientist.com/article/dn8331-lizards-poisonous-secret-is-revealed/ |title=Lizards' poisonous secret is revealed |website=New Scientist|date=16 November 2005|author=Emma Young |access-date= 16 August 2019}}</ref> suggested monitor lizards (including goannas) are venomous and have oral toxin-producing glands.

The goanna's hefty tail can be dangerous when swung, much like a crocodile's tail; small children and dogs have been knocked down by such attacks. Often victims in goanna attacks are bystanders, watching the person antagonising the goanna. Alarmed goannas can mistake standing humans for trees and attempt to climb them to safety, which is painful and can be distressing for both human and goanna.<ref>Underhill D (1993) ''Australia's Dangerous Creatures'', Reader's Digest, Sydney, New South Wales, {{ISBN|0-86438-018-6}}</ref>

===Conservation status===
Goannas are protected species throughout Australia.<ref>{{Cite web |title=Monitor Lizards |url=https://www.wires.org.au/wildlife-information/monitor-lizards |access-date=2023-03-01 |website=www.wires.org.au |language=en-AU}}</ref>

===Culture and folklore===
{{further|Dirawong}}
Goannas have a prominent place in the culture of indigenous Australians. This includes totemic relationships, anthropomorphic representations in [[dreamtime]] stories, and as a food source. Representations of goannas are common in indigenous artwork, not just as food, but also as a symbolic spiritual motif. Smaller goannas and the mighty perentie are often considered two different animals when appearing in aboriginal works, as in the story "How the Goanna and Perentie Got Their Colours".

European settlers perpetuated several [[old wives' tale]]s about goanna habits and abilities; some of these have persisted in modern folklore among campers and bushmen. This includes the above-mentioned exaggeration of goannas dragging off sheep from shepherds' flocks in the night. This might even be exaggerated into child-snatching, rivalling [[drop bear]]s (attack [[koala]]s) as a tourist scarer, but probably more convincing due to the reptiles' carnivorous nature and fearsome appearance.

A common tale was that the bite of a goanna was infused with a powerful, incurable [[venom (poison)|venom]]. Every year after the bite (or every seven years), the wound would flare up again. For many years, herpetologists generally believed goannas were nonvenomous, and lingering illness from their bites was due solely to [[infection]] and [[septicaemia]] as a result of their saliva being rife with [[bacterium|bacteria]] from carrion and other food sources. However, in 2005, researchers at the [[University of Melbourne]] announced that oral venom glands had been found in both goannas and iguanas.<ref>[http://uninews.unimelb.edu.au/articleid_3009.html Goanna venom rocks the reptile record] {{webarchive|url=https://web.archive.org/web/20060824025823/http://uninews.unimelb.edu.au/articleid_3009.html |date=24 August 2006 }}, UniNews Vol. 14, No. 22 28 November - 12 December 2005, University of Melbourne, Retrieved 8 March 2006</ref>

Because the goanna regularly eats snakes (which may involve a fierce struggle), including venomous species, they are often said to be immune to [[snake venom]]. However, no evidence found suggests an actual venom [[immunity (medical)|immunity]]. Other stories say that the lizard eats a legendary plant, or drinks from a healing [[Spring (hydrosphere)|spring]], which neutralises the venom. (This idea is immortalised in [[Banjo Paterson]]'s humorous poem "Johnson's Antidote".)

Goanna fat or oil has been anecdotally imbued with mystical healing properties (possibly in connection with their supposed venom immunity). Aboriginal people traditionally used goanna oil as an important [[bush medicine]], and it also became a common medicine among Caucasians shortly after British settlement in Australia. Said to be a cure-all, and possessing amazing powers of penetration (passing through metal as if it were not there), it was sold among early settlers like [[snake oil]] in the [[Old West]] of North America.

A goanna features as the heroic figure Mr Lizard in the Australian author [[May Gibbs]]’ children's books ''[[Snugglepot and Cuddlepie]]''. A bronze statue of the goanna Mr Lizard has been placed outside the State Library of Victoria.

The villain in the Disney film ''[[The Rescuers Down Under]]'', Percival C. McLeach, has a pet goanna named Joanna.

==References==
{{reflist}}

===Further reading===
* Cogger, H. (1967). ''Australian Reptiles in Colour''. Sydney: A. H. & A. W. Reed, {{ISBN|0-589-07012-6}}
* King, Dennis & Green, Brian. 1999. ''Goannas: The Biology of Varanid Lizards''. University of New South Wales Press. {{ISBN|0-86840-456-X}}
* Underhill, D. (1993). ''Australia's Dangerous Creatures''. Sydney: Reader's Digest. {{ISBN|0-86438-018-6}}

==External links==
*[http://airgale.com.au/Poetry/Johnsons%20Antidote.htm Johnson's Antidote] by [[Banjo Paterson]].
*[https://www.npr.org/templates/story/story.php?storyId=92357274 A Run-In With An Australian Desert Lizard] ([[NPR]])
*[https://www.smh.com.au/environment/conservation/waitress-drags-massive-goanna-from-restaurant-as-shocked-diners-watch-20170221-guhedt.html Waitress removes goanna from restaurant] (includes video)

{{Varanoidea}}

[[Category:Monitor lizards of Australia]]
[[Category:Bushfood]]
[[Category:Bush medicine]]
[[Category:Australian Aboriginal bushcraft]]
[[Category:Reptile common names]]