Monitor lizard
334411
224928448
2008-07-11T01:23:15Z
Metanoid
1233382
/* Origins of the name */
{{Taxobox
| name = Monitor lizards
| image = Varanus varius1.jpg
| image_width = 240px
| image_caption = An [[Australia]]n [[lace monitor]]<br />(''Varanus varius'') on a tree.
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Reptile|Sauropsida]]
| ordo = [[Squamata]]
| subordo = [[Scleroglossa]]
| infraordo = [[Anguimorpha]]
| familia = '''Varanidae'''
| genus = '''''Varanus'''''
| genus_authority = [[Blasius Merrem|Merrem]], 1820
| subdivision_ranks = [[Species]]
| subdivision = [[:Category:Monitor lizards]]
}}
'''Monitor lizards''' are the [[family (biology)|family]] '''Varanidae''', a group of carnivorous [[lizard|lizards]] which includes the largest living lizard, the [[Komodo dragon]]. Varanidae is [[monotypic]], containing only the [[genus]] ''Varanus''.
==Distribution==
The various species of ''Varanus'' cover a vast area, occurring through [[Africa]], the Asian subcontinent from [[India]] and [[Sri Lanka]] to [[China]], down [[Southeast Asia]] to [[Indonesia]], the [[Philippines]], [[New Guinea]], [[Australia]] and islands of the [[Indian Ocean]] and [[South China Sea]].
==Evolutionary overview==
Monitor lizards differ greatly from other [[lizards]] in several ways, possessing a relatively high [[metabolism|metabolic rate]] for [[reptile]]s and several sensory adaptations that benefit the hunting of live prey. Recent research indicates that the varanid lizards, including the [[Komodo dragon]], may have very weak [[venom]].<ref>Fry, B.G; Vidal, N; Norman J.A.; Vonk F.J.; Scheib, H.; Ramjan S.F.R; Kuruppu S.; Fung, K.; Hedges, B.; Richardson M.K.; Hodgson, W.C.; Ignjatovic, V.; Summerhays, R. and Kochva, E. 2006. Early evolution of the venom system in lizards and snakes. ''Nature''. '''439''', 584-588. [http://www.nature.com/nature/journal/v439/n7076/edsumm/e060202-11.html Summary]</ref> The discovery of venom in Monitor Lizards, as well as in [[agamid]] Lizards, led to the [[Toxicofera]] hypothesis: that all venomous reptiles share a common venomous ancestor. Some monitor lizards are apparently capable of [[parthenogenesis]].<ref>{{cite web | url=http://www.nature.com/news/2006/061218/full/061218-7.html | title=Dragon virgin births startle zoo keepers | publisher=Nature | first=Kerri | last=Smith | accessdate=2006-12-20}}</ref> Almost all Monitor lizards are [[carnivorous]].
During the [[Pleistocene]], giant monitor lizards lived in [[Southeast]] Asia and Australiasia, the best known fossil being ''[[Megalania|Megalania prisca]]''. Recently reclassified as a constituent of the genus ''Varanus'', this species is an iconic member of the Pleistocene [[megafauna]] of [[Australia]].
==Origins of the name==
The genus name ''Varanus'' is derived from the [[Arabic (language)|Arabic]] word ''waral'' ورل, which is translated to English as "monitor". It has been suggested that the occasional habit of varanids to stand on their two hind legs and to appear to "monitor" their surroundings led to the original Arabic name.<ref>Pianka, E.R.; King, D.R. and King, R.A. 2004. ''Varanoid Lizards of the World''. Indiana University Press.</ref> According to legend, these lizards were supposed to warn people that crocodiles were nearby.<ref name="Varanidae"> Pianka, Eric R. ''Varinidae'' [http://www.answers.com/topic/monitors-goannas-and-earless-monitors-varanidae-biological-family]</ref>
In [[Tamil language|Tamil]] and [[Malayalam language|Malayalam]] monitor lizards are known as "Udumbu", while in [[Australia]] they are known as [[goanna]]s. In [[Kannada language|Kannada]] monitor lizards are known as "Uda", and in [[Sinhalese language|Sinhalese]], "Kabaragoya".
==Intelligence==
Varanid lizards are very intelligent, and some species can even count.<ref name="King"/> Careful studies feeding ''V. albigularis'' at the [[San Diego Zoo]] varying numbers of snails showed that they can distinguish numbers up to six.<ref name ="King">King, Dennis & Green, Brian. 1999. ''Goannas: The Biology of Varanid Lizards''. University of New South Wales Press. ISBN 0-86840-456-X, p. 43.</ref><ref name="Varanidae"/><ref>The Weekend Australian. July 24-25, 1999, p. 12.</ref> ''V. niloticus'' have been observed to cooperate when foraging.<ref name="King2"/> One varanid lures the female crocodile away from her nest while the other opens the nest to feed on the eggs.<ref name="King2"/> The decoy then returns to also feed on the eggs.<ref name ="King2">King, Dennis & Green, Brian. 1999. ''Goannas: The Biology of Varanid Lizards''. University of New South Wales Press. ISBN 0-86840-456-X, p. 43.</ref ><ref name="Varanidae"/> [[Komodo dragon]]s, ''V. komodoensis,'' at the [[Smithsonian National Zoological Park]] in Washington, D.C., recognize their keepers and seem to have distinct personalities.<ref name="Varanidae"/>
==Monitor lizards in captivity==
Monitor lizards have become a staple in the [[reptile pet]] trade. The most commonly kept monitors are the savannah monitor, white throated monitor, and Acklin's monitor, due to their relatively small size and ease of domestication. Nile monitors, [[water monitor]]s, [[Mangrove goanna|mangrove monitor]]s, and [[Papua monitor]]s have also been kept in captivity. Like all [[reptiles]] that are kept as pets, monitors need hiding places and an appropriate substrate (bedding). Monitors also need a large water dish in which they can soak their entire body. In the wild, monitors will eat anything they can overpower, but [[crickets]], [[superworm]]s, and the occasional [[rodent]] make up most of the captive monitors' diet. Boiled eggs, [[silkworms]], [[earthworms]], and [[feeder fish]] can also be fed to them. Monitor lizards have been compared to reptilian [[cats]] - independent animals with different personalities. However, due to their predatory nature and large size some monitors can be dangerous to keep as pets. Adult nile monitors can reach seven feet in length, and are stronger than an alligator of equal weight.
==Classification==
[[image:Nile_Monitor.JPG|thumb|300px|right|A [[Nile monitor]]]]
[[Image:Monitor lizard australia zoo.jpg|thumb|300px|right|A monitor lizard seen at the [[Australia Zoo]].]]
'''Genus Varanus'''
* [[Spiny-tailed monitor|Spiny-tailed goanna]], ''[[Spiny-tailed monitor|Varanus acanthurus acanthurus]]''
** Common Ridge-tailed Monitor, ''[[Varanus acanthurus brachyurus]]''
** Island Ridge-tailed Monitor, ''[[Varanus acanthurus insulanicus]]''
* Rock Monitor, ''[[Varanus albigularis]]''
** White-throated Monitor, ''[[Varanus albigularis albigularis]]''
** Angola White-throated Monitor, ''[[Varanus albigularis angolensis]]''
** Black-throated Monitor, ''[[Varanus albigularis ionidesi]]''
* Peacock Monitor, ''[[Varanus auffenbergi]]''
* Northern Ridge-tailed Goanna, ''[[Varanus baritji]]''
* [[Black tree monitor]], ''[[Black tree monitor|Varanus beccarii]]''
* [[Bengal monitor]], ''[[Bengal monitor|Varanus bengalensis]]''
* Golden-spotted Tree Monitor, ''[[Varanus boehmei]]''
* Louisiade Tree Monitor, ''[[Varanus bogerti]]''
* [[Short-tailed monitor]], ''[[Short-tailed monitor|Varanus brevicauda]]''
* Pilbara Goanna ''[[Varanus bushi]]''
* Turquois Monitor, ''[[Varanus caerulivirens]]''
* Stripe-tailed Goanna, ''[[Varanus caudolineatus]]''
* Ceram Mangrove Monitor, ''[[Varanus cerambonensis]]''
* Blue-tailed Monitor, ''[[Varanus doreanus]]''
* Dumeril's Monitor, ''[[Varanus dumerilii]]''
* Desert Pygmy Monitor, ''[[Varanus eremius]]''
* [[Savannah monitor]], ''[[Savannah monitor|Varanus exanthematicus]]''
* Finsch's Monitor, ''[[Varanus finschi]]''
* [[Yellow Monitor|Yellow Mangrove Monitor]], ''[[Yellow Monitor|Varanus flavescens]]''
* [[Perentie]], ''[[Perentie|Varanus giganteus]]''
* Pygmy Mulga Goanna, ''[[Varanus gilleni]]''
* Kimberley Rock Monitor, ''[[Varanus glauerti]]''
* Black-palmed Rock Monitor, ''[[Varanus glebopalma]]''
* [[Sand goanna]], ''[[Sand goanna|Varanus gouldii]]''
** Horn's Monitor, ''[[Varanus gouldii horni]]''
** Yellow-spotted Monitor, ''[[Varanus gouldii rubidus]]''
* Desert Monitor, ''[[Varanus griseus]]''
** Western Desert Monitor, ''[[Varanus griseus griseus]]''
** Eastern Desert Monitor, ''[[Varanus griseus caspius]]''
** Thar Desert Monitor, ''[[Varanus griseus koniecznyi]]''
* Mangrove goanna, ''[[Mangrove goanna|Varanus indicus]]''
* Peach Throat Monitor, ''[[Varanus jobiensis]]''
* Hakoi, ''[[Varanus juxtindicus]]''
* Canopy Goanna, ''[[Varanus keithhornei]]''
* King's Goanna, ''[[Varanus kingorum]]''
* [[Komodo Dragon]], ''[[Komodo Dragon|Varanus komodoensis]]''
* Kordo Tree Monitor, ''[[Varanus kordensis]]''
* Panay Monitor, ''[[Varanus mabitang]]''
* Blue-spotted Tree Monitor, ''[[Varanus macraei]]''
* Quince Monitor, ''[[Varanus melinus]]''
* Mertens' Water Monitor, ''[[Varanus mertensi]]''
* Mitchell's Water Monitor, ''[[Varanus mitchelli]]''
* Clouded Monitor, ''[[Varanus nebulosus]]''
* Nile monitor, ''[[Nile monitor|Varanus niloticus]]''
* [[Gray's monitor]], ''[[Gray's monitor|Varanus olivaceus]]''
* Ornate Monitor, ''[[Varanus ornatus]]''
* [[Argus monitor]], ''[[Argus monitor|Varanus panoptes panoptes]]''
** ''[[Varanus panoptes horni]]''
** ''[[Varanus panoptes rubidus]]''
* Pilbara Rock Monitor, ''[[Varanus pilbarensis]]''
* Emerald Tree Monitor, ''[[Varanus prasinus]]''
[[Image:green.tree.monitor.lizard.arp.jpg|thumb|right|250px|[[Emerald tree monitor]] (also called Green tree monitor) lizard ''Varanus prasinus'']]
* Blunt-spined Goanna, ''[[Varanus primordius]]''
* [[Megalania]], ''[[Megalania|Varanus prisca]]'' (extinct)
* ''[[Varanus rainerguentheri]]
* Reisinger's Tree Monitor, ''[[Varanus reisingeri]]''
* Rosenberg's Goanna or Heath Monitor, ''[[Varanus rosenbergi]]''
* Black Roughneck Monitor, ''[[Varanus rudicollis]]''
* [[Crocodile monitor]], ''[[Crocodile monitor|Varanus salvadorii]]''
[[Image:Asian_water_monitor (Varanus_salvator_salvator).JPG|right|250px|thumb|Asian [[water monitor]] (''Varanus salvator salvator'').]]
* [[Water Monitor]], ''[[Water monitor|Varanus salvator]]''
** Asian Water Monitor, ''[[Varanus salvator salvator]]''
** Andaman Islands Water Monitor, ''[[Varanus salvator andamanensis]]''
** Two-striped Water Monitor, ''[[Varanus salvator bivittatus]]''
** Cuming's Water Monitor, ''[[Varanus salvator cumingi]]''
** Black Water Monitor, ''[[Varanus salvator komaini]]''
** Marbled Water Monitor, ''[[Varanus salvator marmoratus]]''
** Negros Water Monitor, ''[[Varanus salvator nuchalis]]''
** Togian Water Monitor, ''[[Varanus salvator togianus]]''
* Spotted Tree Goanna, ''[[Varanus scalaris]]''
* [[Mangrove pygmy goanna]], ''[[Mangrove pygmy goanna|Varanus semiremex]]''
* Spencer's Goanna, ''[[Varanus spenceri]]''
* St. Isabel Mangrove Monitor, ''[[Varanus spinulosus]]''
* Storr's Goanna, ''[[Varanus storri]]''
** Eastern Storr's Goanna, ''[[Varanus storri storri]]''
** Western Storr's Monitor, ''[[Varanus storri ocreatus]]''
* Rossel Island Tree Monitor, ''[[Varanus telenesetes]]''
* Timor Tree Monitor, ''[[Varanus timorensis]]''
* Black-headed Monitor, ''[[Varanus tristis]]''
** Freckled Monitor, ''[[Varanus tristis orientalis]]''
* Lace Monitor, ''[[Varanus varius]]''
* Yemen Monitor, ''[[Varanus yemenensis]]''
* Tri-colored Monitor, ''[[Varanus yuwonoi]]''
* ''[[Varanus zugorum]]''
==References==
{{reflist}}
{{clear}}
==External links==
*[http://www.komodonationalpark.org/downloads/ciofi%201999.pdf Scientific American article]
*[http://www.mampam.com/index.php?option=com_content&task=blogcategory&id=13&Itemid=76 Little Book of Monitors]
{{Wikispecies|Varanidae}}
{{Commonscat|Varanidae}}
[[Category:Monitor lizards|*Monitor lizard]]
[[ar:ورل]]
[[bn:গোসাপ]]
[[ca:Varànid]]
[[cs:Varan]]
[[de:Warane]]
[[et:Varaan]]
[[es:Varanidae]]
[[eo:Varano]]
[[fr:Varanus]]
[[hr:Varani]]
[[id:Biawak]]
[[it:Varanus]]
[[ka:ვარანისებრნი]]
[[lt:Varanai]]
[[hu:Varánuszfélék]]
[[ms:Biawak]]
[[nl:Varanen]]
[[ja:オオトカゲ科]]
[[no:Varaner]]
[[pl:Waranowate]]
[[pt:Varanidae]]
[[ro:Varanidae]]
[[ru:Вараны]]
[[su:Bayawak]]
[[fi:Varaanit]]
[[sv:Varaner]]
[[tl:Bayawak]]
[[uk:Варани]]