Editing Earless monitor lizard

{{Short description|Species of lizard}}
{{Speciesbox
| image = Real Lanthanotus borneensis.jpg
| display_parents = 3
| grandparent_authority = Steindachner, 1877
| genus = Lanthanotus
| parent_authority = [[Franz Steindachner|Steindachner]], 1878
| species = borneensis
| authority = [[Franz Steindachner|Steindachner]], 1878
| status = EN
| status_system = IUCN3.1
| status_ref = <ref>{{cite iucn |author=Das, I. |author2=Auliya, M. |year=2021 |title=''Lanthanotus borneensis'' |volume=2021 |page=e.T102342572A102342580 |doi=10.2305/IUCN.UK.2021-2.RLTS.T102342572A102342580.en |access-date=21 January 2022}}</ref>
| status2 = CITES_A2 
| status2_system = CITES 
| status2_ref = <ref>{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}</ref>
}}
[[File:Lanthanotus skulls (cropped).png|thumb|227x227px|Earless monitor skull]]
The '''earless monitor lizard''' ('''''Lanthanotus borneensis''''') is a [[semiaquatic]], brown lizard native to the [[Southeast Asia]]n island of [[Borneo]]. It is the [[monotypic|only living species]] in the family '''Lanthanotidae''' and it is related to the true [[monitor lizard]]s.<ref>{{NRDB family |family=Lanthanotidae |date=19 January |year=2021}}</ref><ref name=EoR>{{cite book |editor1=Cogger, H.G. |editor2=Zweifel, R.G. |author= Bauer, Aaron M.|year=1998|title=Encyclopedia of Reptiles and Amphibians|publisher= Academic Press|location=San Diego|pages= 156–157|isbn= 0-12-178560-2}}</ref><ref name=Das2013>{{cite journal | author=Das, I. | year=2013 | title=''Lanthanotus borneensis'', the Bornean Earless Monitor | journal=Herpetological Review | volume=44 | issue=4 | page=553 |url=http://theherpetofaunalbiologygroup.weebly.com/uploads/1/4/1/5/14155652/415-_das_hr_cover_dec2013.pdf }}</ref>

==Taxonomy==
The earless monitor lizard was [[species description|described]] in 1878 by [[Franz Steindachner]].<ref name=ReptileDatabase>{{NRDB species |genus=Lanthanotus |species=borneensis |accessdate=19 January 2021}}</ref> The [[genus]] name ''Lanthanotus'' means "hidden ear" and the species name ''borneensis'' refers to its home island of [[Borneo]].<ref name="Sprackland1999">{{cite journal |author=Sprackland, R.G. |year=1999 |title=Sarawak's Earless Monitor Lizard (''Lanthanotus borneensis'') |journal=Reptiles |issue=March |pages=72–79}}</ref> The uniqueness of the species was immediately recognized and Steindachner placed it in its own family, Lanthanotidae. In 1899, [[George Albert Boulenger]] relegated it to the family [[Helodermatidae]], together with the [[Heloderma|beaded lizards]] and [[Gila monster]], on the basis of morphological similarities.<ref name="Sprackland1999" /> Further studies were conducted in the 1950s where it was found that although it is related to Helodermatidae, this relationship is relatively distant. The similarity is in part the result of [[convergent evolution]] and they should be recognized as separate families.<ref name="Sprackland1999" /> Both are part of a broader [[Anguimorpha]], but the relationship among the various families has been a matter of dispute. Several earlier studies have placed the earless monitor lizard together with Helodermatidae and [[Varanidae]] (true monitor lizards) in [[Varanoidea]].<ref name=Ast2001>{{cite journal | author=Ast, J.C. | year=2001 | title=Mitochondrial DNA evidence and evolution in Varanoidea (Squamata) | journal=Cladistics | volume=17 | issue=11 | pages=211–226 | doi=10.1111/j.1096-0031.2001.tb00118.x| pmid=34911248 | hdl=2027.42/72302 | s2cid=53623809 | hdl-access=free }}</ref> More recent [[Genetics|genetic]] evidence has found that the nearest relative of the earless monitor lizard is Varanidae.<ref name=Wiens2012>{{cite journal |last1=Wiens |first1=John J. |last2=Hutter |first2=Carl R. |last3=Mulcahy |first3=Daniel G. |last4=Noonan |first4=Brice P. |last5=Townsend |first5=Ted M. |last6=Sites |first6=Jack W. |last7=Reeder |first7=Tod W. |title=Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species |journal=Biology Letters |date=2012 |volume=8 |issue=6 |pages=1043–1046 |doi=10.1098/rsbl.2012.0703 | pmid=22993238 | pmc=3497141 }}</ref><ref name=Pyron2013>{{cite journal |last1=Pyron |first1=R. Alexander |last2=Burbrink |first2=Frank T. |last3=Wiens |first3=John J. | year=2013 | title=A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes | journal=BMC Evolutionary Biology | volume=13 | issue=1 | page=93 | doi=10.1186/1471-2148-13-93| pmid=23627680 | pmc=3682911 |doi-access=free |bibcode=2013BMCEE..13...93P }}</ref> Most authorities continue to recognize them as separate families as the [[Genetic divergence|divergence]] between them is deep,<ref name=ReptileDatabase/><ref name=Wiens2012/><ref name=Pyron2013/> but some have suggested that the earless monitor lizard should be included as a subfamily, Lanthanotinae, of the Varanidae.<ref>{{cite journal |last1=Conrad |first1=Jack L. |last2=Rieppel |first2=Olivier |last3=Grande |first3=Lance |title=Re-assessment of varanid evolution based on new data from ''Saniwa ensidens'' Leidy, 1870 (Squamata, Reptilia) |journal=American Museum Novitates |date=2008 |issue=3630 |pages=1–15 |doi=10.1206/596.1 | hdl=2246/5939 | s2cid=83550662 |url=https://www.biodiversitylibrary.org/itempdf/280854 }}</ref> Together they form a [[clade]] and its [[sister group]] is [[Shinisauridae]]; at a higher level the sister groups of these three are Helodermatidae and others families in Anguimorpha.<ref name=Wiens2012/><ref name=Pyron2013/> The [[most recent common ancestor]] diverged in the mid-[[Cretaceous]].<ref name=Das2013/><ref>{{cite journal |last1=Douglas |first1=Michael E. |last2=Douglas |first2=Marlis R. |last3=Schuett |first3=Gordon W. |last4=Beck |first4=Daniel D. |last5=Sullivan |first5=Brian K. |title=Conservation phylogenetics of helodermatid lizards using multiple molecular markers and a supertree approach |journal=Molecular Phylogenetics and Evolution |date=April 2010 |volume=55 |issue=1 |pages=153–167 |doi=10.1016/j.ympev.2009.12.009 |pmid=20006722|bibcode=2010MolPE..55..153D }}</ref>

The extinct ''[[Cherminotus]]'' known from [[Late Cretaceous]] fossil remains in [[Mongolia]] has been considered a member of Lanthanotidae, but this is disputed.<ref>{{cite journal | author1=Gao, K. | author2=M.A. Norell | year=2000 | title=Taxonomic composition and systematics of Late Cretaceous lizard assemblages from Ukhaa Tolgod and adjacent localities, Mongolia, Gobi desert | journal=Bulletin of the American Museum of Natural History | volume=249 | pages=1–118 | doi=10.1206/0003-0090(2000)249<0001:tcasol>2.0.co;2 | hdl=2246/1596 | s2cid=129367764 | url=https://zenodo.org/record/5350258 |hdl-access=free}}</ref>

==Distribution and habitat==
The earless monitor lizard is [[Endemism|endemic]] to the Southeast Asian island of Borneo, where it is known from [[Sarawak]] in [[East Malaysia]], as well as [[West Kalimantan|West]] and [[North Kalimantan]] in [[Indonesia]].<ref name=Yapp2012>{{cite journal |last1=Yaap |first1=B. |last2=Paoli |first2=G.D. |last3=Angki |first3=A. |last4=Wells |first4=P.L. |last5=Wahyudi |first5=D. |last6=Auliya |first6=M. | year=2012 | title=First record of the Borneo Earless Monitor ''Lanthanotus borneensis'' (Steindachner, 1877) (Reptilia:Lanthanotidae) in West Kalimantan (Indonesian Borneo) | journal=Journal of Threatened Taxa | volume=4 | issue=11 | pages=3067–3074 | doi=10.11609/JoTT.o3055.3067-74| doi-access=free |s2cid=52023963 }}</ref><ref name=Vergner2013>{{cite journal | author=Vergner, I. | year=2013 | title=První nález varanovce bornejského ve Východním Kalimantanu a další setkání se vzácným ještěrem [First Discovery of the Earless Monitor Lizard in Eastern Kalimantan] | journal=Živa | issue=March | pages=131–133 | language=cs }}</ref><ref name=Langner2017>{{cite journal | author=Langner, C. | year=2017 | title=Hidden in the heart of Borneo — Shedding light on some mysteries of an enigmatic lizard: First records of habitat use, behavior, and food items of ''Lanthanotus borneensis'' Steindachner, 1878 in its natural habitat | journal=Russian Journal of Herpetology | volume=24 | issue=1 | pages=1–10 | doi=10.30906/1026-2296-2019-24-1-1-10}}</ref> Until late 2012, its known range in North Kalimantan was a part of [[East Kalimantan]].<ref>{{cite web | title=House agrees on creation of Indonesia's 34th province: 'North Kalimantan' | date=23 October 2012 | url=http://www.theborneopost.com/2012/10/23/house-agrees-on-creation-of-indonesias-34th-province-north-kalimantan/ | publisher=The Borneo Post | access-date=26 June 2017}}</ref> It was also confirmed to be found in [[Brunei]] for the first time in 2022, in the country's [[Temburong District]].<ref>{{Cite web |date=2022-10-22 |title=Treasured find in Green Jewel » Borneo Bulletin Online |url=https://borneobulletin.com.bn/treasured-find-in-green-jewel/ |access-date=2022-10-22 |website=Treasured find in Green Jewel |language=en-US}}</ref> Prior to the discovery, it was believed that they may occur there and has been recorded c. {{convert|100|km|mi|abbr=on|-1}} from the border.<ref name="CITESprop">{{cite journal | title=Considerations of proposals for amendment of Appendices I and II | date=5 October 2016 | url=https://cites.org/sites/default/files/eng/cop/17/prop/060216/E-CoP17-Prop-32.pdf | publisher=[[Convention on International Trade in Endangered Species of Wild Fauna and Flora]], Seventeenth meeting of the Conference of the Parties Johannesburg (South Africa) | journal=CoP17 | volume=32 | pages=1–9 | access-date=25 June 2017}}</ref> There are no records from [[Sabah]], [[Central Kalimantan]] or [[South Kalimantan]].<ref name=Langner2017/><ref name=CITESprop/>

It is found in lowlands at elevations below {{convert|300|m|ft|abbr=on|-2}} near streams and marshes.<ref name=Das2010>{{cite book | author=Das, I. | year=2010 | title=Reptiles of South-East Asia | publisher=New Holland | page=226 | isbn=978-1-84773-347-4}}</ref><ref name=Traffic2015>{{Cite journal | author1=Stoner, S.S. | author2=V. Nijman | year=2015 | title=The case for CITES Appendix I-listing of Earless Monitor Lizards ''Lanthanotus borneensis'' | journal=TRAFFIC Bulletin | volume=27 | issue=2 | pages=55–58}}</ref> These are typically in [[Borneo lowland rain forests|rainforests]], but it is also found in streams flowing through degraded habitats such as agricultural land, mature fruit tree gardens and [[palm oil]] plantations, and reportedly may occur in [[rice paddies]].<ref name=Yapp2012/><ref name=Langner2017/><ref name=Das2010/> The streams it inhabits are often rocky.<ref name=Yapp2012/><ref name=Langner2017/> Its habitat is tropical with air and water temperatures that generally are about {{convert|22-29|C|F|abbr=on}},<ref name=Vergner2013/><ref name=Langner2017/> and captives reportedly prefer {{convert|24-28|C|F|abbr=on}}.<ref name=Pianka2004>{{cite book |editor=Pianka |editor2=King |editor3=King | year=2004 | title=Varanoid Lizards of the World | publisher=Indiana University Press | pages=535–538 | isbn=0-253-34366-6}}</ref> At a site with a high density of earless monitor lizards the water was clear and had a neutral [[pH]].<ref name=Langner2017/> It is associated with the same microhabitat as ''[[Tropidophorus]]'' water skinks and in some places its range overlaps with ''[[Tropidophorus brookei|T. brookei]]''.<ref name=Langner2017/>

==Appearance==
Earless monitor lizards have a cylindrical body, long neck, short limbs, long sharp claws, small eyes, semitransparent lower eyelids, and six longitudinal rows of strongly [[keeled scales]].<ref name=Das2010/><ref name=Pianka2006>{{Cite book | title=Lizards: Windows to the Evolution of Diversity | author1=Pianka, E.R. | author2=L.J. Vitt | publisher=University of California Press | year=2006 | isbn=978-0520248472 | pages=[https://archive.org/details/lizardswindowsto00pian/page/240 240–241, 253] | url=https://archive.org/details/lizardswindowsto00pian/page/240 }}</ref> The species is extensively covered in [[Osteoderm|osteoderms]].<ref>{{Cite journal |last1=Anderson Maisano |first1=Jessica |last2=Bell |first2=Christopher J. |last3=Gauthier |first3=Jacques A. |last4=Rowe |first4=Timothy |date=December 2002 |title=The Osteoderms and Palpebral in Lanthanotus borneensis (Squamata: Anguimorpha) |url=http://www.bioone.org/doi/abs/10.1670/0022-1511%282002%29036%5B0678%3ATOAPIL%5D2.0.CO%3B2 |journal=Journal of Herpetology |language=en |volume=36 |issue=4 |pages=678–682 |doi=10.1670/0022-1511(2002)036[0678:TOAPIL]2.0.CO;2 |issn=0022-1511|url-access=subscription }}</ref> Despite the name, they are capable of hearing, although lack a [[eardrum|tympanum]], an ear opening and other externally visible signs of ears.<ref name=EoR/><ref>{{cite journal | author=McDowell, S.B. | year=1967 | title=The extracolumella and tympanic cavity of the "earless" monitor lizard, ''Lanthanotus borneensis'' | journal=Copeia | volume=1967 | issue=1 | pages=154–159 | doi=10.2307/1442189| jstor=1442189 }}</ref> The upperparts are orangish-brown, and the underside is mottled dark brown and whitish, pale yellowish, [[ochre]] or [[Rust (color)|rusty]].<ref name=Sprackland1999/><ref name=Yapp2012/><ref name=Das2010/> The tail is [[Prehensile tail|prehensile]] and if it is lost, it is not regenerated.<ref name=Pianka2006/> The skin is [[Moulting|shed]] infrequently, possibly less than once a year.<ref name=Pianka2006/> There are both reports of the skin shedding in one piece (similar to snakes),<ref name=Pianka2006/> or in smaller pieces (as typical of lizards).<ref name=BTDescription>{{cite web | title=Lanthanotus borneensis – Description | url=https://www.borneo-taubwaran.de/en/description/description/ | publisher=borneo-taubwaran.de | access-date=27 July 2019 }}</ref> Overall the sexes are alike, but males have a distinctly broader head and broader tail base than females.<ref name=Langner2017/> The differences between the sexes are clearly noticeable from an age of about three years.<ref name=BTGeschlechtsunterschiede>{{cite web | title=Geschlechtsunterschiede | url=https://borneo-taubwaran.de/haltung/geschlechtsunterschiede/ | publisher=borneo-taubwaran.de | access-date=13 July 2018 | language=de | archive-url=https://web.archive.org/web/20180813175229/https://borneo-taubwaran.de/haltung/geschlechtsunterschiede/ | archive-date=13 August 2018 | url-status=dead }}</ref> They sometimes oscillate the throat (similar to frogs) and the [[forked tongue]] is sometimes flicked (similar to snakes).<ref name=Langner2017/> They can make a gentle, squeaky vocalization.<ref name=Langner2017/>

===Size===
Adult earless monitor lizards typically have a snout-to-[[Cloaca|vent]] length (SVL) of about {{convert|20|cm|in|abbr=on|0}},<ref name=Das2010/> and a total length of about {{convert|40|cm|in|abbr=on|0}}.<ref name=BTDescription/> Eighteen wild individuals, six males and twelve females, ranged from {{convert|15.6|to(-)|22|cm|in|abbr=on}} in SVL, {{convert|17.4|to(-)|22.1|cm|in|abbr=on}} in tail length (disregarding one individual missing much of its tail), and {{convert|48|to(-)|120|g|oz|abbr=on}} in weight (disregarding one sickly and skinny individual).<ref name=Langner2017/> Among these, the largest total length (SVL+tail) was a male that measured {{convert|44.1|cm|in|abbr=on}}, which also is the longest recorded in the wild.<ref name=Langner2017/> A [[Zoological specimen|specimen]] collected in the 1960s has a total length of {{convert|20|in|cm|abbr=on|disp=flip}},<ref name=Sprackland1999/> and near the time of its death an individual kept at the [[Bronx Zoo]] from 1968 to 1976 had a total length of {{convert|47|cm|in|abbr=on|1}} and weighed {{convert|209|g|oz|abbr=on}}, but it was highly obese.<ref name=Mendyk2015>{{cite journal | author=Mendyk |author2=Shuter |author3=Kathriner | year=2015 | title=Historical notes on a living specimen of ''Lanthanotus borneensis'' (Squamata: Sauria: Lanthanotidae) maintained at the Bronx Zoo from 1968 to 1976 | journal=Biawak | volume=9 | issue=2 | pages=44–49 }}</ref> When hatching the total length of the young is about {{convert|7-14|cm|in|abbr=on|0}}.<ref name=Vergner2013/><ref name=Shirawa2015>{{cite journal | author1=Shirawa, T. | author2=S. Bacchini | year=2015 | title=Captive Maintenance and the First Reproduction of Borneo Earless Monitors (''Lanthanotus borneensis'') | journal=Herp Nation | volume=18}}</ref><ref name=ViennaOnline2017>{{cite web | title=Taubwarane: Tiergarten Schönbrunn verzeichnet seltenen Zuchterfolg | url=http://www.vienna.at/taubwarane-tiergarten-schoenbrunn-verzeichnet-seltenen-zuchterfolg/5175066 | publisher=Vienna Online | date=7 March 2017| access-date=25 June 2017 | language=de}}</ref> When one year old, their total length is about {{convert|23-25|cm|in|abbr=on|0}}.<ref name=BTAufzucht>{{cite web | title=Aufzucht | url=https://borneo-taubwaran.de/haltung/aufzucht/ | publisher=borneo-taubwaran.de | access-date=13 July 2018 | language=de | archive-url=https://web.archive.org/web/20180813175217/https://borneo-taubwaran.de/haltung/aufzucht/ | archive-date=13 August 2018 | url-status=dead }}</ref>The Record size of earless monitor is 55 cm.<ref>https://muse.jhu.edu/pub/3/edited_volume/chapter/1930780</ref>

==Behavior==
Earless monitor lizards are generally strictly nocturnal animals, although exceptional daytime observations in the open have been reported.<ref name=Yapp2012/><ref name=Langner2017/> The day is usually spent near water in burrows that can be up to {{convert|30|cm|ft|abbr=on|0}} long or under logs, rocks or vegetation.<ref name=Das2013/><ref name=Das2010/> They are generally quite inactive and not agile, but can make surprisingly fast spurts when startled,<ref name=Langner2017/> and will rapidly catch prey items placed in front of them.<ref name=Shirawa2015/> During one study where 19 individuals were located during the night, about half were in the water and the other half near water on land.<ref name=Langner2017/> In captivity they sometimes remain virtually immobile underwater for hours, periodically lifting the nose above the water's surface to breathe.<ref name=BTVerhalten>{{cite web | title=Verhalten im Terrarium | url=https://borneo-taubwaran.de/haltung/verhalten-im-terrarium/ | publisher=borneo-taubwaran.de | access-date=13 July 2018 | language=de | archive-url=https://web.archive.org/web/20180813210256/https://borneo-taubwaran.de/haltung/verhalten-im-terrarium/ | archive-date=13 August 2018 | url-status=dead }}</ref> When underwater, the semitransparent lower eyelids are generally closed, covering the eyes.<ref name=Langner2017/> It has been speculated that the prehensile tail is wrapped around stones, roots and other things underwater to avoid being swept along during floods.<ref name=Shirawa2015/>

===Bite===
{{See also|Toxicofera}}

Although generally docile and inactive when handled, males are usually more aggressive than females when caught.<ref name=Langner2017/> In one case, a scientist received a deep bite in his finger, but did not experience any effects that could indicate a presence of venom in the bite (unlike the related and venomous beaded lizards, Gila monster and some monitor lizards).<ref name=Langner2017/> This supported decades-old dissection studies where no venom glands or grooves in the teeth were found.<ref name=Sprackland1999/> Others kept in captivity were found to bite often, resulting in wounds that are relatively deep (compared to those from similar-sized lizards) and can bleed extensively,<ref name=Shirawa2015/> with [[blood clotting]] reportedly being slower than in normal wounds.<ref name=BTDescription/> Recent studies have found both venom glands,<ref>{{cite journal | author1=Fry BG | author2=Winter K | author3=Norman JA | author4=Roelants K | author5=Nabuurs RJ | author6=van Osch MJ | author7=Teeuwisse WM | author8=van der Weerd L | author9=McNaughtan JE | author10=Kwok HF | author11=Scheib H | author12=Greisman L | author13=Kochva E | author14=Miller LJ | author15=Gao F | author16=Karas J | author17=Scanlon D | author18=Lin F | author19=Kuruppu S | author20=Shaw C | author21=Wong L | author22=Hodgson WC | year=2010 | title=Functional and structural diversification of the Anguimorpha lizard venom system | journal=Molecular & Cellular Proteomics | volume=9 | issue=11 | pages=2369–2390 | doi=10.1074/mcp.M110.001370 | doi-access=free | pmid=20631207 | pmc=2984233 }}</ref> and toxic compounds in the bite of this species.<ref name=Koludarov2017>{{cite journal | author1=Koludarov I | author2=Jackson TN | author3=Brouw BOD | author4=Dobson J | author5=Dashevsky D | author6=Arbuckle K | author7=Clemente CJ | author8=Stockdale EJ | author9=Cochran C | author10=Debono J | author11=Stephens C | author12=Panagides N | author13=Li B | author14=Manchadi MR | author15=Violette A | author16=Fourmy R | author17=Hendrikx I | author18=Nouwens A | author19=Clements J | author20=Martelli P | author21=Kwok HF | author22=Fry BG | year=2017 | title=Enter the dragon: the dynamic and multifunctional evolution of anguimorpha lizard venoms | journal=Toxins |location=Basel | volume=9 | issue=8 | page=242 | doi=10.3390/toxins9080242 | pmid=28783084 | pmc=5577576 | doi-access=free }}</ref> The main components are [[kallikrein]]s (to a lesser degree [[Cysteine-rich secretory protein|CRiSP]]) with the primary effect being the cleaving of [[fibrinogen]], which is important for blood clotting.<ref name=Koludarov2017/> However, this effect is quite weak in the venom of the earless monitor lizard compared to that of many other venomous reptiles, including some of the true monitor lizards.<ref name=Dobson2019>{{cite journal | author1=Dobson, J.S. | author2=C.N. Zdenek | author3=C. Hay | author4=A. Violette | author5=R. Fourmy | author6=C. Cochran | author7=B.G. Fry | year=2019 | title=Varanid lizard venoms disrupt the clotting ability of human fibrinogen through destructive cleavage | journal=Toxins |location=Basel | volume=11 | issue=5 | page=255 | doi=10.3390/toxins11050255| pmc=6563220 | pmid=31067768 | doi-access=free }}</ref>

===Feeding===
They typically feed on [[earthworm]]s, [[crustacean]]s and fish.<ref name=Das2010/> In captivity, they will eat fish (both whole and pieces), earthworms, [[squid]], [[shrimp]], [[tadpole]]s, [[yolk]] from [[green sea turtle]] eggs, pieces of pig and chicken liver, baby mice and [[mussel]]s, but refuse to take bird eggs and legs of frog.<ref name=Langner2017/><ref name=Mendyk2015/><ref name=ViennaOnline2017/><ref name=BTVerhalten/> In captivity adults typically eat once or twice per week, but sometimes enter longer periods where they do not feed.<ref name=BTVerhalten/> Unusually for a lizard, they can swallow prey while submerged underwater. The only other monitor species reported to do this is [[Mertens' water monitor]].<ref name=Mendyk2015/> They appear to be able to do this by draining water from their nostrils, similar to turtles.<ref name=Shirawa2015/>

===Breeding and life cycle===
Like their closest relatives, they are [[oviparous]], although little is known about their reproduction.<ref name=EoR/> Based on captive observations a pair will mate repeatedly over a period of a few months, with each session lasting for hours.<ref name=MReising>{{cite web | author=Reising, M. | title=Lanthanotus borneensis | url=http://s592754522.website-start.de/artenteil/lanthanotus-borneensis/ | publisher=Heloderma | access-date=26 June 2017 | language=de}}</ref> In one case, a single mating lasted 44 hours.<ref name=Shirawa2015/> They mate in the water.<ref name=MReising/><ref name=BTPaarung>{{cite web | title=Paarung | url=https://borneo-taubwaran.de/haltung/paarung/ | publisher=borneo-taubwaran.de | access-date=13 July 2018 | language=de | archive-url=https://web.archive.org/web/20180813210246/https://borneo-taubwaran.de/haltung/paarung/ | archive-date=13 August 2018 | url-status=dead }}</ref> In the wild mating has been seen in February,<ref name=Das2013/> and a female caught in April was likely [[Gravidity and parity#Gravidity in biology|gravid]].<ref name=Langner2017/> The 2–12 (average 8) oval eggs measure about {{convert|3|cm|in|abbr=on}} long and have a leathery white shell.<ref name=Sprackland1999/><ref name=Das2010/><ref name=Shirawa2015/><ref name=BTEiablageInkubationSchlupf>{{cite web | title=Eiablage, Inkubation und Schlupf | url=https://borneo-taubwaran.de/haltung/eiablage-inkubation-und-schlupf/ | publisher=borneo-taubwaran.de | access-date=13 July 2018 | language=de | archive-url=https://web.archive.org/web/20180813175328/https://borneo-taubwaran.de/haltung/eiablage-inkubation-und-schlupf/ | archive-date=13 August 2018 | url-status=dead }}</ref> They are deposited on land.<ref name=BTEiablageInkubationSchlupf/> In captivity the eggs hatch after about three months at a temperature of {{convert|27|C|F|abbr=on}}.<ref name=Shirawa2015/><ref name=ViennaOnline2017/> Adult males are likely [[Territory (animal)|territorially]] aggressive, as a survey of a locality found twice as many females as males, and most of the males (but no females) had various injuries, such as loss of toes or tail, and scarring on the head or neck.<ref name=Langner2017/> In captivity, young up to 6 months old have been kept in groups, and adults have been kept singly, as pairs or a single male with several females; more than one adult male causes problems.<ref name=BTVerhalten/> The lifespan is unknown, but—despite the very limited knowledge of reptile keeping at the time—an individual that entered captivity as a young adult in the 1960s lived for more than 7.5 years after its capture (growing from {{convert|38.2|to|47|cm|in|abbr=on|disp=or}} in total length),<ref name=Mendyk2015/> and others have reportedly surpassed a decade in captivity.<ref name=Sprackland1999/>

== Status and conservation ==
The earless monitor lizard has been rated by the [[IUCN]] as [[Endangered species|endangered]] (its range covers less than {{convert|500|km2|mi2|abbr=on|disp=or}}).<ref name=Traffic2015/> The species is usually considered very rare, but it is easily overlooked and as recently as 1999 the only published confirmed records were from Sarawak.<ref name=Sprackland1999/> Confirmation from [[Kalimantan]] only appeared later.<ref name=Langner2017/> In some areas locals are unaware of its presence or consider it rare, but in others it may be common. At one site in West Kalimantan, 17 of 21 locals asked were aware of its presence and most of these considered it common.<ref name=Yapp2012/> At three other sites in the region the majority asked were aware of its presence, but less than half considered it common.<ref name=Yapp2012/> Elsewhere in West Kalimantan, a three-night survey of a {{convert|400|m|ft|abbr=on}} long section of a stream, as well as two adjacent streams, located 19 earless monitor lizards, representing an unusually high density for a lizard of this size.<ref name=Langner2017/> Despite this high density in a stream used by locals for washing, fishing and as a source of drinking water, they only reported seeing the species very rarely and some had never seen it.<ref name=Langner2017/> Nevertheless, at present the earless monitor lizard is only known for certain from a relatively small number of sites.<ref name=CITESprop/><ref name=Traffic2015/>

About 100 museum specimens are known and most major [[natural history museum]]s have one or more in their collection.<ref name=Sprackland1999/> These were generally collected in the 1960s–1980s or earlier,<ref name=Vergner2013/> often during floods when earless monitor lizards were swept along the current and ended up in [[fishing trap]]s.<ref name=Sprackland1999/><ref name=Pianka2006/> From the 1960s to the 1990s small numbers entered the pet trade.<ref name=Mendyk2015/> In 2012 it was featured in a [[Japan]]ese reptile keepers magazine and in the following years a larger number of individuals entered captivity.<ref name=CITESprop/><ref name=TodayOnline2016>{{Cite web | title=Malaysia goes to battle for Godzilla-like lizard | url=http://www.todayonline.com/world/asia/malaysia-goes-battle-godzilla-lizard | publisher=Today Online | date=5 August 2016 | access-date=25 June 2017}}</ref> From May 2014 to October 2015 at least 95 earless monitor lizards appeared in the trade in Asia ([[Hong Kong]], Indonesia, Japan and Malaysia), [[Europe]] (Czech Republic, France, Germany, Netherlands, Russia, Ukraine and the United Kingdom) and the United States.<ref name=Traffic2014>{{Cite book| title=Keeping an ear to the ground: monitoring the trade in Earless Monitor Lizards | author1=Nijman, V. | author2=S.S. Stoner | publisher=TRAFFIC | year=2014 | isbn=978-983-3393-41-1 | location=Petaling Jaya, Selangor, Malaysia}}</ref> Collecting the species from the wild is illegal; the earless monitor lizard has been protected in Malaysia since 1971, in Brunei since 1978 and in Indonesia since 1980.<ref name=Traffic2014/> Penalties range from a fine of US$1,600 and one year's imprisonment (Brunei) to $7,850 and three years' imprisonment (Malaysia), to $8,600 and five years' imprisonment (Indonesia).<ref name=Traffic2014/> As a precaution some scientists that have discovered individuals in the wild have refused to provide the exact location, only describing it in very broad terms, citing fears of alerting wildlife traders.<ref name=Yapp2012/><ref name=Langner2017/> In 2015, a smuggler was caught in an Indonesian airport with 8 individuals and in 2016 another was caught in an Indonesian airport with 17 individuals.<ref name=TodayOnline2016/> This trade is supported by the very high price. When first entering the market in Japan, a pair sold for [[Japanese yen|¥]]3 million (more than US$25,000). Although the price has since fallen by more than 90% due to increased availability, it remains valuable.<ref name=TodayOnline2016/> Significant declines in price have also been noted elsewhere.<ref name=Guardian2015>{{Cite web | author= Neslen, A. | title=Lizard traffickers exploit legal loopholes to trade at world's biggest fair | url=https://www.theguardian.com/environment/2015/nov/11/lizard-traffickers-exploit-legal-loopholes-to-trade-at-worlds-biggest-fair | work=The Guardian | date=11 November 2015 | access-date=25 June 2017}}</ref> Unlike all other monitor species, the earless monitor lizard was not listed on [[CITES]], which would restrict trade at an international level.<ref name=TodayOnline2016/><ref name=Traffic2014/> In 2016 it was proposed that it should be placed on [[CITES Appendix I]],<ref name=CITESprop/> and in 2017 it was afforded a level of protection when placed on [[CITES Appendix II|Appendix II]] (export quota is zero for wild individuals for commercial purposes).<ref name=CITES2017>{{Cite web | title=Appendices I, II and III | url=https://www.cites.org/eng/app/appendices.php | publisher=[[CITES]] | date=4 April 2017 | access-date=25 June 2017}}</ref>

The first confirmed captive breeding was at a zoo in Japan in 2014.<ref name=Mendyk2015/><ref name=Shirawa2015/> A couple of years later a few European zoos initiated a [[breeding program]]; in 2017 it was bred at [[Schönbrunn Zoo]] in Austria, and in 2018 it was bred a [[Prague Zoo]] in the Czech Republic and [[Moscow Zoo]] in Russia.<ref name=ViennaOnline2017/><ref>Archived at [https://ghostarchive.org/varchive/youtube/20211211/AcCoFxhBgPg Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20200618214114/https://www.youtube.com/watch?v=AcCoFxhBgPg&gl=US&hl=en Wayback Machine]{{cbignore}}: {{cite web | title=Seltener Zuchterfolg: Taubwarane im Tiergarten Schönbrunn | date=7 March 2017 | url=https://www.youtube.com/watch?v=AcCoFxhBgPg | publisher= Zoovienna Tiergarten Schönbrunn | language=de | access-date=25 June 2017}}{{cbignore}}</ref><ref>{{cite web | title="Holy Grail" of lizard species born in Prague Zoo | date=16 October 2018 | url=https://www.reuters.com/article/us-czech-lizard/holy-grail-of-lizard-species-born-in-prague-zoo-idUSKCN1MQ2BL | publisher=Reuters | access-date=27 July 2019 }}</ref><ref>{{cite journal | author1=Voronin, A.N. | author2=S.V. Kudryavtsev | year=2019 | title=''Lanthanotus borneensis'' (Steindachner, 1878): Captive husbandry and breeding | journal=Russian Journal of Herpetology | volume=26 | issue=1 | pages=57–62 | doi=10.30906/1026-2296-2019-26-1-57-62 | s2cid=214465130 }}</ref> There have been other breeding reports by private keepers and captive bred individuals have been offered for sale, but some of these may not involve genuine cases of captive breeding.<ref name=Traffic2015/>

[[Habitat destruction|Habitat loss]] represents another serious threat, as forests in Borneo rapidly are being replaced by oil palm plantations.<ref name=Langner2017/><ref name=Pianka2006/><ref name=TodayOnline2016/> However, the earless monitor lizard can survive in high densities in areas surrounded by degraded habitats (including oil palm plantations), and rocky streams, possibly its preferred habitat, are relatively unaffected by humans.<ref name=Langner2017/>

==References==
{{Reflist}}

==External links==
{{Wikispecies|Lanthanotus borneensis|''Lanthanotus borneensis''}}
{{Commons category}}
* Maisano, Jessie (2001). [http://digimorph.org/specimens/Lanthanotus_borneensis/ Lanthanotus borneensis]. Digital Morphology. Accessed June 20, 2010.
{{Squamata families}}
{{Varanoidea}}
{{Taxonbar|from1=Q904780|from2=Q14177398|from3=Q13033818}}

[[Category:Monitor lizards]]
[[Category:Lizards of Asia]]
[[Category:Endemic fauna of Borneo]]
[[Category:Reptiles of Indonesia]]
[[Category:Reptiles of Malaysia]]
[[Category:Reptiles described in 1878]]
[[Category:Taxa named by Franz Steindachner]]
[[Category:Reptiles of Borneo]]
[[Category:Fauna of the Borneo lowland rain forests]]