lace monitor

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John White, the surgeon-general of New South Wales, described this species as the variegated lizard (Lacerta varia) in 1790.{{cite book |last1=White |first1=John |title=Journal of a Voyage to New South Wales, with sixty-five plates of non-descript animals, birds, lizards, serpents, curious cones of trees, and other natural productions |date=1790 |publisher=Debrett |location=London |page=253 |url=https://biodiversitylibrary.org/page/50707700}} George Shaw reported that several specimens were taken back to England.{{cite book|chapter-url=https://biodiversitylibrary.org/page/44484149 |title=The naturalist's miscellany, or Coloured figures of natural objects |volume=3 |chapter=The Variegated Lizard |via=Biodiversity Heritage Library |access-date=9 May 2019|publisher=Printed for Nodder & Co. |year=1789 }} French naturalist François Marie Daudin gave it the name Tupinambis variegatus in 1802, and noted two forms.{{cite book |last1=Daudin |first1=François Marie |title=Histoire naturelle, générale et particulière, des reptiles : ouvrage faisant suite à l'Histoire naturelle générale et particulière, composée par Leclerc de Buffon, et rédigée par C.S. Sonnini |date=1802 | volume=3 |publisher=De l'Imprimerie de F. Dufart,an X-XI |location=Paris |pages=72 |url=https://biodiversitylibrary.org/page/39967204}} German naturalist Blasius Merrem established the genus Varanus in 1820,{{cite book |last1=Merrem |first1=Blasius |title=Versuch eines Systems der Amphibien |date=1820 |publisher=J.C. Kreiger |location=Marburg |pages=58 |url=https://biodiversitylibrary.org/page/4040713}} with V. varius as the first mentioned member set as its type species by John Edward Gray in 1827.{{cite journal |last1=Gray |first1=John Edward |title=A synopsis of the genera of saurian reptiles, in which some new genera are indicated, and the others reviewed by actual examination |journal= The Philosophical Magazine|date=1827 |volume=2 |issue=7 |pages=54–58 |url=https://books.google.com/books?id=FzFDAQAAMAAJ&pg=PA54|doi=10.1080/14786442708675620 }}

French zoologists André Marie Constant Duméril and Gabriel Bibron described two specimens in 1836, one in their possession and one from the collection of English zoologist Thomas Bell as Varanus bellii "Le Varan de Bell".{{cite book | last1= Duméril |first1=André Marie Constant| last2=Bibron |first2=Gabriel |year= 1836 | title =Erpétologie Générale ou Histoire Naturelle Complète des Reptiles |location= Paris |publisher= Roret |volume=3 |id= part 3 |page= 943 |url= https://biodiversitylibrary.org/page/31898070 |language=fr }} This turned out to be a banded colour phase of the lace monitor that coexists with normal-coloured individuals, and is either autosomal dominant or codominant genetically.{{cite book |last1=Brown |first1=Danny |title=A Guide to Australian Monitors in Captivity |date=2012 |publisher=ABK Publications |isbn=978-0-9758200-7-0 |pages=171–172 |url=https://books.google.com/books?id=jABRDwAAQBAJ&pg=PA171 }} It is sometimes called the Bell's phase lace monitor.

The species is commonly known as lace monitor, tree goanna, or lacy.{{cite book |last=Weavers| first=Brian| editor1=King, Ruth Allen |editor2=Pianka, Eric R. |editor3=King, Dennis |title=Varanoid lizards of the world |publisher=Indiana University Press |location=Bloomington |year=2004 |pages=488–501 |isbn=978-0-253-34366-6}} It was known as wirriga to the Eora and Darug inhabitants of the Sydney basin,{{cite book|author=Troy, Jakelin|year=1993|title=The Sydney Language|publisher=Self-published| location=Canberra|isbn=978-0-646-11015-8|page=53 | url=https://www.williamdawes.org/docs/troy_sydney_language_publication.pdf}} and gugaa to the Wiradjuri people of southern New South Wales.{{cite web |last1=Green |first1=Dick |title=Wiradjuri Heritage Study |url=https://wagga.nsw.gov.au/__data/assets/pdf_file/0020/4646/Wiradjuri_Heritage_Study2.pdf |website=Wagga Wagga City Council |access-date=8 September 2019}}

The lace monitor is monotypic; no subspecies are recognised. However, genetic analysis of its mitochondrial DNA (mtDNA) across its range revealed three main clades: a north Queensland clade separated by the Burdekin Gap from a clade spanning from southern Queensland through inland New South Wales across the Murray–Darling basin and into southeastern South Australia. This is divided from a third clade that spans coastal eastern Australia (northern New South Wales to eastern Victoria) by the McPherson Range and Great Dividing Range. This last clade is thought to have diverged from the first two clades around 2.7 million years ago, while these clades separated around 850,000 years ago.{{cite journal |first1=Peter J. |last1= Smissen | first2=Jane |last2=Melville |first3= Joanna |last3=Sumner |first4= Tim S.| last4= Jessop |title=Mountain barriers and river conduits: phylogeographical structure in a large, mobile lizard (Varanidae: Varanus varius) from eastern Australia |journal= Journal of Biogeography|date=2013 |volume=40 |issue=9 |pages=1729–40 |doi=10.1111/jbi.12128|bibcode= 2013JBiog..40.1729S |s2cid= 85139053 }}

Lace monitor fossils from the middle Pleistocene have been found in Naracoorte Caves in South Australia.{{Cite journal |last=Donato |first=Isabella |last2=Palci |first2=Alessandro |last3=Hutchinson |first3=Mark N. |last4=Reed |first4=Elizabeth H. |date=2024-09-26 |title=Putting a Name to a Face: Using Geometric Morphometrics to Identify Middle Pleistocene Varanid Cranial Fossils from Naracoorte Caves |url=https://bioone.org/journals/journal-of-herpetology/volume-58/issue-3/23-056/Putting-a-Name-to-a-Face--Using-Geometric-Morphometrics/10.1670/23-056.full |journal=Journal of Herpetology |volume=58 |issue=3 |doi=10.1670/23-056 |issn=0022-1511|url-access=subscription }}

Genetic analysis of mtDNA shows the lace monitor to be the closest relative (sister taxon) of the Komodo dragon, with their common ancestor diverging from a lineage that gave rise to the crocodile monitor (Varanus salvadorii) of New Guinea.{{cite journal|last1=Vidal|first1=N|last2=Marin|first2=J|last3=Sassi|first3=J|last4=Battistuzzi|first4=FU|last5=Donnellan|first5=S|last6=Fitch|first6=AJ|last7=Fry|first7=BG|last8=Vonk|first8=FJ|last9=Rodriguez de la Vega|first9=RC|last10=Couloux|first10=A|last11=Hedges|first11=SB|title=Molecular evidence for an Asian origin of monitor lizards followed by Tertiary dispersals to Africa and Australasia|journal=Biology Letters|date=2012|volume=8|issue=5|pages=853–855|doi=10.1098/rsbl.2012.0460|pmid=22809723|pmc=3441001}}{{cite journal|doi=10.1071/ZO05038|title=A molecular phylogeny of the Australian monitor lizards (Squamata:Varanidae) inferred from mitochondrial DNA sequences|journal=Australian Journal of Zoology|volume=54|issue=4|pages=253–269|year=2006|last1=Fitch|first1=A. J.|last2=Goodman|first2=A. E.|last3=Donnellan|first3=S. C.}}{{cite journal|doi=10.1111/j.1096-0031.2001.tb00118.x|title=Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)|journal=Cladistics|volume=17|issue=3|pages=211–226|year=2001|last1=Ast|first1=J.|pmid=34911248 |hdl=2027.42/72302|url=https://deepblue.lib.umich.edu/bitstream/2027.42/72302/1/j.1096-0031.2001.tb00118.x.pdf|hdl-access=free}} The divergence between lace monitor and Komodo dragon lineages has been calculated to have occurred around 13 million years ago, or 11.5 million years ago.

File:Argus Monitor and Lace Monitor.jpg (left), lace monitor (right)|247x247px]]The second-largest monitor in Australia after the perentie, the lace monitor can reach 2 m (7 ft) in total length, or 76.5 cm snout–vent length (SVL), and weigh up to 14 kg (30 lb). The male reaches sexual maturity when it has a SVL of 41.5 cm. Females are generally smaller than males, with a maximum SVL of 57.5 cm, and becoming sexually mature at a SVL of 38.5 cm. The tail is long and slender and about 1.5 times the length of the head and body.Ehmann, Harald. (1992). Encyclopedia of Australian Animals: Reptiles, p. 158. The Australian Museum. {{ISBN|0-207-17379-6}} (Reptiles).Wildlife of Tropical North Queensland: Cooktown to Mackay, p. 233. (2000). Queensland Museum. {{ISBN|0-7242-9349-3}}

The tail is cylindrical at its base, but becomes laterally compressed towards the tip.

Historically, it has been described as growing as much as 8 ft long. Regardless of the accuracy of these reports, lace monitors of such size likely no longer exist.{{Cite book|last1=Royal Society of New South Wales.|url=https://www.biodiversitylibrary.org/bibliography/29666|title=Transactions of the Philosophical society of New South Wales, 1862-1865.|last2=Wales|first2=Royal Society of New South|date=1866|publisher=Printed by Reading and Wellbank|location=Sydney|doi=10.5962/bhl.title.29666}}

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Lace monitors are found in two forms. The main form is dark grey to dull bluish-black with numerous, scattered, cream-coloured spots. The head is black and the snout is marked with prominent black and yellow bands extending under the chin and neck. The tail has narrow black and cream bands, which are narrow and get wider towards the end of the tail. Juveniles have more defined and prominent banding, with five narrow black bands on the neck and eight bands on the body.{{cite book |first1=Stephen K. |last1=Wilson|first2=David G. |last2=Knowles |title=Australia's Reptiles: A Photographic Reference to the Terrestrial Reptiles of Australia |location=Sydney |publisher=Collins |year=1988 |isbn=978-0-7322-0011-4| page=361}}

The other type, known as Bell's form, is typically found in west of the Great Dividing Range from Woodgate, Eidsvold, and Mitchell in Queensland to Bourke, Macksville and Port Macquarie in New South Wales. It has also been reported from Healesville, Rushworth, and Murchison in Victoria and the Flinders Ranges in South Australia. It has a base colour of yellow-brown or yellow with fine black mottling and broad, black or dark brown bands from the shoulders to the tail. The top of the head is black.

File:Goanna Head 2.jpg

These common terrestrial and often arboreal monitors are found in eastern Australia and range from Cape Bedford on Cape York Peninsula to south-eastern South Australia. They frequent both open and closed forests and forage over long distances (up to {{cvt|3|km|abbr=on}} a day).

The lace monitor is considered to be a least-concern species according to the International Union for Conservation of Nature.

They are mainly active from September to May, but are inactive in cooler weather and shelter in tree hollows or under fallen trees or large rocks.

File:Goanna coming down a tree in our garden.jpg, Queensland]]

Despite its large size and mass, the lace monitor is an adept climber. One was recorded climbing a brick wall to seek shelter in a thunderstorm.{{cite journal |last1=Jones |first1=Alan A. |title=Shelter from the Storm: An Unconventional Refuge for a Wild Varanus varius (White, 1790) (Reptilia: Sauria: Varanidae) |journal=Biawak |date=2013 |volume=7 |issue=2 |pages=54–55 |url=http://varanidae.org/Vol7_No2.pdf}} Young lace monitors are even more arboreal than adults. They often spend most of their adult lives in the same area; one individual was recorded living in the same tree for years.{{Cite book|last=Bennett|first=Daniel|title=A little book of monitor lizards.|publisher=Viper Press|date=1 January 1995|pages=132–133}}

A field study in Burragorang, New South Wales found that males over 5 kg ranged over home territories of 65.5 ± 10.0 hectares. They moved around much less in winter.{{cite journal |last1=Pascoe |first1=Jack |last2=Flesch |first2=Jason S. |last3=Duncan |first3=Michael |last4=Le Pla |first4=Mark |title=Territoriality and Seasonality in the home range of adult male free-ranging lace monitors (Varanus varius) in South-eastern Australia |journal=Herpetological Conservation and Biology |date=2019 |volume=14 |issue=1 |pages=97–104}}

In at least the temperate regions, the breeding season takes place in the summer.

Male lace monitors fight each other by grappling while standing on the hind legs in the breeding season, and up to six males may gather around a receptive female to try and court her. Mating takes several hours.File:Lace Monitors fighting.jpgFemales lay an average of eight eggs in active termite nests either on the ground or in the trees, although they may lay as many as 12 eggs. When such nests are in short supply, females often fight over them or lay the eggs in burrows and perhaps hollow logs. The eggs overwinter to hatch 6–7 months later. Hatchlings remain around the nest for about a week or more before leaving its vicinity. Females may return to the same termite nest to lay their next clutch of eggs. These monitors can potentially live to reach over 20 years of age.

Lace monitors are predominantly carrion eaters, feeding on already dead carcasses of other wildlife. They consist of insects, reptiles, small mammals, birds, with eggs and young birds and mammals making up a larger part of their diet in spring and early summer.{{cite journal |doi=10.1071/WR01001|title=Diet of a large carnivorous lizard, Varanus varius|year=2001|last1=Guarino|first1=Fiorenzo|journal=Wildlife Research|volume=28|issue=6|page=627}} Lace monitors search for food on the ground, retreating to a nearby tree if disturbed. They also forage in areas inhabited by people, raiding chicken coops for poultry and eggs, and rummaging through unprotected domestic garbage bags and rubbish bins in picnic and recreational areas.

A 2012 study in Gippsland found that populations of lace monitors near two rubbish tips were thirty five times greater, with individuals around twice as heavy, as populations in natural forest. The lizards near rubbish tips foraged predominantly on food waste there, with a greater caloric intake. These populations had 5.3 males for each female, compared with 1.9 males per female in natural areas. Despite the apparent increase in population and size, the long-term effect of human impact on the species is unclear.{{cite journal |doi=10.1371/journal.pone.0034069|title=Demographic and Phenotypic Effects of Human Mediated Trophic Subsidy on a Large Australian Lizard (Varanus varius): Meal Ticket or Last Supper?|year=2012|last1=Jessop|first1=Tim S.|last2=Smissen|first2=Peter|last3=Scheelings|first3=Franciscus|last4=Dempster|first4=Tim|journal=PLOS ONE|volume=7|issue=4|pages=e34069|pmid=22509271|pmc=3317928|bibcode=2012PLoSO...734069J|doi-access=free}}

As they often swallow meat whole, they can be at risk of harm from some meat scraps; one was reported with a T-bone steak bone stuck in its throat and another with a plastic fork in its stomach.{{cite journal |last1=Gillett |first1=Amber |last2=Jackson | first2=Richard |title=Human Food Scrap Ingestion in Two Wild Lace Monitors Varanus varius |journal=Biawak |date=2010 |volume=4 |issue=3 |pages=99–102 |url=http://varanidae.org/4_3.pdf}} Another swallowed six golf balls that a chicken owner had placed in their coop to prompt their chickens to lay eggs.{{cite news |last1=Huxley |first1=Jennifer |first2= Joanne |last2=Shoebridge | first3= Damien | last3=Larkins |title=Goanna narrowly avoids surgery after swallowing six golf balls in chicken coop raid |url=https://www.abc.net.au/news/2019-04-02/goanna-swallows-six-golf-balls/10961784 |access-date=10 September 2019 |agency=ABC News |publisher=Australian Broadcasting Corporation |date=2 April 2019}}

They frequently attack the large composting nests of scrub turkeys to steal their eggs, and often show injuries on their tails inflicted by male scrub turkeys pecking at them to drive them away.

The species (particularly larger individuals) declined in numbers when the species encountered the advancing cane toad; however, lace monitors were abundant in some areas where cane toads had been established for many years. Fieldwork published in 2016 found that larger individuals were less cautious in what they ate, but all lace monitors quickly learned to avoid toads after they had been poisoned.{{cite journal |doi=10.1007/s10530-016-1097-2|title=The impacts of a toxic invasive prey species (The cane toad, Rhinella marina) on a vulnerable predator (The lace monitor, Varanus varius)|year=2016|last1=Jolly|first1=Christopher J.|last2=Shine|first2=Richard|last3=Greenlees|first3=Matthew J.|journal=Biological Invasions|volume=18|issue=5|pages=1499–1509|bibcode=2016BiInv..18.1499J |s2cid=14921372}}

Lace monitors are close to the top of the food chain, though dingo packs, wedge-tailed eagles, and wild boars occasionally prey upon them.{{usurped|1=[https://web.archive.org/web/20160601013321/http://www.spiffa.org/uploads/2/6/7/5/2675656/do_ecosystems_need_top_predators_in_south_east_australia.pdf Do ecosystems need top predators? A brief review of predator-prey imbalances in south-east Australia with reference to tree dieback on the Mornington Peninsula]}}Webb, JONATHAN K. "Observation of three dingoes killing a large lace monitor (Varanus varius)." Australian Mammalogy 19.1 (1996): 55-56.Geary, N. "Notes on the Wedge-tailed Eagle." Emu - Austral Ornithology 31.4 (1932): 288-289.

File:Lace Monitor, Varanus Varius.jpg (NSW)]]Venom glands in lace monitors have been confirmed. The venom is similar to that produced by snakes but not enough to cause serious harm.{{cite web | last = Smith | first = Deborah | title = Venom research bad-mouths goannas | publisher = Sydney Morning Herald | date = 2005-11-18 | url = https://www.smh.com.au/national/venom-research-bad-mouths-goannas-20051118-gdmglo.html| doi = | accessdate = 2022-11-21}} In late 2005, University of Melbourne researchers discovered that all monitors may be somewhat venomous. Previously, bites inflicted by monitors were thought to be prone to infection because of bacteria in their mouths, but the researchers showed that the immediate effects were more likely caused by envenomation. Bites on the hand by lace monitors have been observed to cause swelling within minutes, localised disruption of blood clotting, and shooting pain up to the elbow, which can often last for several hours.{{Cite journal|last1=Fry|first1=Bryan G.|last2=Vidal|first2=Nicolas|last3=Norman|first3=Janette A.|last4=Vonk|first4=Freek J.|last5=Scheib|first5=Holger|last6=Ramjan|first6=S. F. Ryan|last7=Kuruppu|first7=Sanjaya|last8=Fung|first8=Kim|last9=Hedges|first9=S. Blair|date=16 November 2005|title=Early evolution of the venom system in lizards and snakes|journal=Nature|language=En|volume=439|issue=7076|pages=584–588|doi=10.1038/nature04328|pmid=16292255|bibcode=2006Natur.439..584F |s2cid=4386245|issn=1476-4687}}

In vitro testing showed lace monitor mouth secretion impacts on platelet aggregation, drops blood pressure and relaxes smooth muscle; the last effect mediated by an agent with the same activity as brain natriuretic peptide. Liquid chromatography/mass spectrometry found ample proteins with molecular masses of 2-4 kilodaltons (corresponding with natriuretic peptide), 15 kilodaltons (type III Phospholipase A2), and 23-25 kilodaltons (cysteine-rich secretory proteins and kallikrein) in these secretions.

Washington State University biologist Kenneth V. Kardong and toxicologists Scott A. Weinstein and Tamara L. Smith, have cautioned that labelling these species as venomous oversimplifies the diversity of oral secretions in reptiles, and overestimates the medical risk of bite victims.{{cite book|last1=Weinstein|first1=Scott A.|last2=Smith|first2=Tamara L.|last3=Kardong|first3=Kenneth V.|editor=Stephen P. Mackessy|title=Handbook of Venoms and Toxins of Reptiles|chapter-url=https://books.google.com/books?id=x_vME799de4C&pg=PA84|access-date=18 July 2013|date=14 July 2009|publisher=Taylor & Francis|isbn=978-1-4200-0866-1|pages=76–84|chapter=Reptile Venom Glands Form, Function, and Future }}

The lace monitor was eaten by the Wiradjuri people; local wisdom advised eating lace monitors that came down from trees as those that had eaten on the ground tasted of rotting meat. The Tharawal ate the species' eggs, collecting them in sand on riverbanks in the Nattai and Wollondilly.{{cite book |last1=Wesson |first1=Sue |url= |title=Murni Dhungang Jirrar: Living in the Illawarra |publisher=Department of Education and Communities, NSW Government |citeseerx=10.1.1.729.6424}} Goanna remains have been recovered in middens in what is now Sydney.{{Cite book| title = Sydney's Aboriginal past: investigating the archaeological and historical records | last = Attenbrow | first = Val | year = 2010

| publisher = UNSW Press | location = Sydney | page = 74 | isbn = 978-1-74-223116-7| oclc = 659579866 }} The lace monitor is bred in captivity as an exotic pet.

File:Goanna Varianus varius.jpg|Underside markings

File:Goana lace monitor.jpg|Climbing a tree

File:Goana444.jpg|Climbing a tree

File:Wild Lace Monitor in Brisbane Forest Park.jpg|Brisbane Forest Park, Queensland

File:Varanus varius (12209494164).jpg|Head closeup

File:Lace monitor444.jpg|Demonstrating camouflage

File:Lace monitor (goanna).jpg|Cairns, Queensland

File:Lace Monitors.jpg|Lace monitors fighting

File:Varanus varius -Airlie Beach, Queensland, Australia -molting-8.jpg|Molting in Queensland

File:Lace Monitor at Peacock - Richmond Range National Park.jpg|At Peacock - Richmond Range National Park

File:Lace Monitor at The Pass, Byron Bay.jpg|Lace monitor at the pass, Byron Bay, New South Wales

File:Goannayeramba.jpg|Yeramba Lagoon

File:Close up of Lace monitor in Healesville Sanctuary, Victoria, Australia.jpg|Healesville Sanctuary, Victoria, Australia

File:Lace monitor, Sydney, 2023.webm|Audley, Sydney

File:Lace monitor at Lane Cove National Park.jpg|Lane Cove National Park

File:Lace Monitor (Glenrock State Conservation Area).jpg|Glenrock State Conservation Area, Newcastle, New South Wales

{{Reflist}}

• King, Dennis & Green, Brian. (1999). Goannas: The Biology of Varanid Lizards. University of New South Wales Press. {{ISBN|0-86840-456-X}}
• Wilson, Steven & Swan Gerry (2003). A Complete Guide to Reptiles of Australia. Reed New Holland Australia {{ISBN|1-876334-72-X}}
• Wilson, Stephen K. (1985). Australia's Reptiles. {{ISBN|0-207-17707-4}}.

{{Varanoidea}}

{{Taxonbar|from=Q924941}}

Category:Varanus

Category:Monitor lizards of Australia

Category:Reptiles described in 1790

Category:Reptiles of New South Wales

Category:Taxa named by George Shaw