Varanus salvadorii

Varanus salvadorii was first described as Monitor salvadorii by Wilhelm Peters and Giacomo Doria in 1878 based on a female specimen with a snout-to-vent length of {{cvt|48|cm}}, and a {{cvt|114|cm}} long tail. It was subordinated to the genus Varanus under the name Varanus salvadorii by George Albert Boulenger in 1885.{{cite book |author1=Netherton, J. |author2=Badger, D. P. |title=Lizards: A Natural History of Some Uncommon Creatures--Extraordinary Chameleons, Iguanas, Geckos, and More |url=https://archive.org/details/lizards00davi/page/140 |url-access=registration |publisher=Voyageur Press |location=Stillwater, MN |year=2002 |pages=140–141 |isbn=978-0-7603-2579-7}}

There are no formally recognized subspecies of V. salvadorii, but the captive reptiles market distinguishes those from Sorong, Jayapura and Merauke based on the color of their snout and the overall brightness of their color pattern.

The generic name, Varanus, is derived from the Arabic waral ({{lang|ar|ورل}}), meaning "lizard". The term "monitor" is thought to have come about from confusion between waral and the German {{lang|de|warnen}}, meaning "warning". The term "goanna" came about as a corruption of the name "iguana". The specific name, salvadorii, is derived from a Latinization of Tommaso Salvadori,Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. (Varanus salvadorii, p. 232). an Italian ornithologist who worked in New Guinea.

The genus Varanus originated in Asia about 40 million years ago (Mya). Around 15 Mya, a tectonic connection between Australia and Southeast Asia allowed the varanids to spread into what is now the Indonesian archipelago.{{cite journal |author=Ciofi, Claudio |journal=Scientific American |url=http://www.sciam.com/article.cfm?id=the-komodo-dragon |title=The Komodo Dragon|year=1999 |volume=280 |issue=3 |pages=84–91 |doi=10.1038/scientificamerican0399-84 |bibcode=1999SciAm.280c..84C |access-date=2006-12-21 |url-access=subscription }}

Based upon DNA sequences of three nuclear and two mitochondrial genes, cladistic analysis identifies the crocodile monitor as a member of a species cluster that includes the lace monitor (V. varius) and the Komodo dragon (V. komodoensis).{{cite journal|last1= Vidal|first1= N.|last2= Marin|first2= J.|last3= Sassi|first3= J.|last4= Battistuzzi|first4= F.U.|last5= Donnellan|first5= S.|last6= Fitch|first6= A.J.|last7= Fry|first7= B.G.|last8= Vonk|first8= F.J.|last9= Rodriguez de la Vega|first9= R.C.|last10= Couloux|first10= A.|last11= Hedges|first11= S.B.|title= Molecular evidence for an Asian origin of monitor lizards followed by Tertiary dispersals to Africa and Australasia |journal= Biology Letters|volume= 8|issue= 5|year= 2012|pages= 853–855|doi= 10.1098/rsbl.2012.0460|pmid= 22809723|pmc= 3441001|doi-access= free|bibcode= 2012BiLet...8..853V}} Morphological considerations suggest that the megalania (V. priscus) was also a member of the group.{{cite journal|last1= Conrad|first1= J.L.|last2= Ast|first2= J.C.|last3= Montanari|first3= S.|last4= Norell|first4= M.A.|title=A combined evidence phylogenetic analysis of Anguimorpha (Reptilia: Squamata) |journal= Cladistics|volume= 27|issue= 3|year =2011|pages= 230–277|doi= 10.1111/j.1096-0031.2010.00330.x|pmid= 34875778|s2cid= 84301257|doi-access= free}} Monitors apparently colonized Australasia from Asia about 32 Mya; the varius clade then arose about 17 Mya.

The largest of the seven species of monitors found on the island of New Guinea, crocodile monitors occur in both the state Papua New Guinea and the Indonesian region of West Papua. It inhabits the high and low canopies of the lowland rainforests and coastal mangrove swamps, sometimes venturing out of these areas during floods in the rainy seasons. No detailed field investigation data are available for V. salvadorii, so the full extent of its range is unknown. Its remote and generally inaccessible habitat is an obstacle to detailed study of this monitor in its natural habitat.

File:Varanus Salvadorii Köln Zoo 31122014 2.jpg]]

A characteristic feature of the crocodile monitor is its blunt, bulbous snout, which makes it look different from every other monitor on New Guinea, and suggested the common name "tree crocodile". The body of the lizard is dark green with rings of yellow spots.{{cite web | title = New Guinea Crocodile Monitor |publisher = Central Florida Zoo and Botanial Gardens | url = http://www.centralfloridazoo.org/our-animals/new-guinea-monitor.shtml | access-date = 2008-08-21 |archive-url = https://web.archive.org/web/20080528025013/http://www.centralfloridazoo.org/our-animals/new-guinea-monitor.shtml |archive-date = May 28, 2008}} The tail is banded yellow and black and is extremely long.

Its teeth are long, straight, and sharp. Its claws are prominent and strongly curved.{{cite web |title=Crocodile Monitor |work=Leeward Community College's Zoology 101 |publisher=Honolulu Zoo |url= http://www.honoluluzoo.org/crocodile_monitor.htm |access-date=2008-08-21 |archive-url=https://web.archive.org/web/20081004211439/http://www.honoluluzoo.org/crocodile_monitor.htm |archive-date=2008-10-04 |url-status=dead}} Males reach a considerably larger size than females in both weight and length, and also tend to have a more robust head.{{citation | editor=Reh, B. | year=2021 | title=Best Practice Guidelines for the Crocodile Monitor (Varanus salvadorii) | publisher=EAZA Reptile Taxon Advisory Group | edition=1 }}

File:CROCODILE MONITOR.jpg in the background.]]

Like many monitor species, the crocodile monitor has mammal-like aerobic abilities; a positive pressure gular pump in the animal's throat assists lung ventilation. Unlike most lizards that cannot breathe efficiently while running, because of Carrier's constraint, the gular pump of monitor lizards enables them to overcome the effect of one lung at a time being compressed by their running gait.{{cite news| last=Brainerd| first = E. |title=Research by UMass Amherst Biologist Suggests that Lizards Offer Evolutionary Freeze-Frame| publisher=UMass Amherst |date=1999 |url=http://www.umass.edu/newsoffice/newsreleases/articles/12664.php |access-date=19 December 2008 |archive-url=https://web.archive.org/web/20090630230838/http://www.umass.edu/newsoffice/newsreleases/articles/12664.php |archive-date=30 June 2009 |url-status=dead |df=dmy-all}} The evolutionary development of the gular pump is functionally analogous to that of the diaphragm in mammals, which ventilates the lung independently of locomotion. Even amongst monitors, the crocodile monitor is one of the most agile species, quickly running up tree trunks and leaping from branch to branch. Investigation supports the idea that gular breathing is an evolutionary development that masks the effect of Carrier's constraint.{{cite journal |author1=Owerkowicz, T. |author2=Farmer, C. G. |author3=Hicks, J. W. |author4=Brainerd, E. L. |title=Contribution of Gular Pumping to Lung Ventilation in Monitor Lizards | journal = Science |volume=284 |issue=5420 |pages=1661–1663 |date=1999 |doi=10.1126/science.284.5420.1661 |pmid=10356394 |bibcode=1999Sci...284.1661O |citeseerx=10.1.1.486.481}}

The crocodile monitor's typical reported length is less than {{cvt|200|cm}} with a matching body mass of about {{cvt|20|kg}}.{{cite journal |last1=Turner |first1=Frederick B. |last2=Jennrich |first2=Robert I. |last3=Weintraub |first3=Joel D. |title=Home ranges and body size of lizards |journal=Ecology |date=1969 |volume=50 |issue=6 |pages=1076–1081 |doi=10.2307/1936898 |jstor=1936898 |bibcode=1969Ecol...50.1076T}}{{cite book |author1=Pianka, E. |author2=King, D. |author3=King, R. |year=2004 |title=Varanoid Lizards of the World |place=Bloomington |publisher=Indiana University Press}} Such a weight is questionable for healthy individuals of this slender species, and a review of healthy captive adults found that a typical weight was up to {{cvt|6|kg}}. Ten specimens were found to weigh only {{cvt|5|to|6.38|kg}} at a length of {{cvt|1.16|to|2.25|m}}.{{cite web |url=http://memim.com/varanus-salvadorii.html |title=Varanus salvadorii |publisher=Memim Encyclopedia |access-date=2015-06-09}} The average size of crocodile monitors caught in one study was {{cvt|99.2|cm}} with a weight of {{cvt|2.02|kg}}, but these must have been young specimens.{{cite journal |author1=Iyai, D.A. |author2=Murwanto, A.G. |author3=Killian, A.M. |year=2011 |title=Hunting and Ethnozoology Systems of Monitor Lizards (Fam. Varanidae) Utilized by Yaur Tribe at National Park of Cenderawasih Gulf |journal=Biota |volume=16 |issue=2 |pages=278−286}}

Crocodile monitors are unique among extant varanid species in that its tail is much longer than the snout-to-vent length in both juveniles and adults. The tail generally is 2–2.7 times the snout-to-vent length.{{cite book |author=Sprackland, R. G. |title=Giant lizards |publisher=T.F.H. Publications |location=Neptune, NJ |year=1992 |isbn=978-0-86622-634-9}}

Crocodile monitors upon hatching measure about {{cvt|45|cm}} long and they reach maturity when about {{cvt|170|cm}}.{{cite journal |last1=Auliya |first1=M. |last2=Koch |first2=A. |year=2020 |title=Visual Identification Guide to the Monitor Lizard Species of the World (Genus Varanus) |publisher=Federal Agency for Nature Conservation, IUCN SSC Monitor Lizard Specialist Group |journal=BFN-Skripten |volume=552}} Reports of the maximal length vary greatly and are the subject of much dispute. It possibly attains the greatest length among extant species of lizards, although it is considerably less massive than the Komodo dragon.{{cite book |author=Wood, G. |url=https://archive.org/details/guinnessbookofan00wood |title=The Guinness Book of Animal Facts and Feats |year=1983 |publisher=Guinness Superlatives |isbn=978-0-85112-235-9}} Crocodile monitors have been confirmed to reach up to {{cvt|255|cm}} in length (record by a specimen at Museum Koenig).{{cite journal |last1=Böhme |first1=W. |last2=Ziegler |first2=T. |year=1997 |title=Großwarane im Museum Koenig, mit Bemerkungen zu Afrikas größter Echse |journal=Tier und Museum |volume=5 |issue=3 |pages=65–74}} Some have been claimed to be much larger, including an individual from Konedobu that reportedly was {{cvt|323|cm}} long, one from Kikori that reportedly was {{cvt|427|cm}} and an individual from Port Moresby that reportedly was {{cvt|475|cm}} long, but these sizes are unverified.

Claims of crocodile monitors attaining large weights also are unverified; the species is much more slender than Komodo dragons of comparable length.{{cite web|url=http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/crocodile-monitor.htm|title=ANIMAL BYTES - Crocodile Monitor |work=Seaworld |access-date=2013-04-22|archive-date=2007-12-14 |archive-url=https://web.archive.org/web/20071214161143/http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/crocodile-monitor.htm|url-status=dead}}

File:CrocMonitor.jpg]]

The crocodile monitor is a highly arboreal lizard. It can hang onto branches with its rear legs, and occasionally use its tail as a prehensile grip. The primary function of the tail, however, is as a counterbalance when leaping from branch to branch. As in some other Varanus species, the tail also may be used for defense, as captive specimens may attempt to lash keepers with their tails.{{cite web|last=Stafford |first=Grey |title=Aloha to three crocodile monitors |publisher=Wildlife World Zoo |url=http://www.azfamily.com/3tvexclusives/stories/KTVKZooTales20070424_crocodile-monitors.3cd03e2.html |access-date=2008-08-21 |url-status=dead |archive-url=https://web.archive.org/web/20090701023157/http://www.azfamily.com/3tvexclusives/stories/KTVKZooTales20070424_crocodile-monitors.3cd03e2.html |archive-date=July 1, 2009 }} This species occasionally is seen in the pet trade, but has a reputation for aggression and unpredictability.{{cite journal | last = Bayless | first = Mark K. | title = The Artellia: Dragons of the Trees | journal = Reptiles | volume = 6 | issue = 6 | pages = 32–47 | date = June 1, 1998 }} Although they are known to rest and bask in trees, they sleep on the ground or submerged in water.

These monitors rise up on their hind legs to check their surroundings, behaviour that also has been documented in Gould's monitors (V. gouldii). They are known to exhibit a warning posture, in which they carry their tails rolled up behind them. According to native belief, they give a warning call if they see crocodiles. In general crocodile monitors avoid human contact, but their bite is capable of causing infection, like the Komodo dragon's. One fatality was reported from a bite in 1983 when a Papuan woman was bitten and later died from an infection.

File:Varanus salvadorii skull (cropped).png

The teeth of crocodile monitors do not resemble those of other monitor species, which typically are blunt, peglike, and face slightly rearward. Their upper teeth are long, fang-like, set vertically in the jawbone, adapted to hooking into fast-moving prey such as birds, bats, and rodents. Their lower teeth are housed in a fleshy sheath. In the wild, crocodile monitors are the top predator in New Guinea, feeding on birds (such as Cacatua sp.), eggs, small mammals (such as rats and bandicoots), frogs, reptiles, and carrion.{{Cite web|url=https://animaldiversity.org/accounts/Varanus_salvadorii/|title = Varanus salvadorii (Crocodile Monitor)| website=Animal Diversity Web }}{{cite web | url=https://biocyclopedia.com/index/monitor_lizards/varanus_salvadorii.php | title=Varanus Salvadorii }} Natives have reported that it can take down pigs, deer, and hunting dogs, and hauls its prey into the canopy to consume it. Captive specimens have been known to eat fish, frogs, rodents, chickens, and dog food.{{cite book |author1=McDade, Melissa C. |author2=Grzimek, Bernhard |author3=Schlager, Neil |author4=Hutchins, Michael |author5=Trumpey, Joseph E. |author6=Olendorf, Donna |title=Grzimek's Animal Life Encyclopedia |publisher=Thomson/Gale |location=Detroit |year=2004 |isbn=978-0-7876-5362-0 |page=368}}

This species has been observed hunting prey in a unique fashion for monitor lizards. Rather than following its prey to ambush it from behind, the crocodile monitor may stalk its prey and anticipate where it will run, meeting it headlong.

Reproduction of crocodile monitors has only been observed in captivity, so nothing is known about its reproduction in the wild. The egg clutches, comprising four to 12 eggs, are deposited around October to January, with the eggs showing a difference in dimensions, a phenomenon for which no explanation is known. Dimensions vary from {{cvt|7.5|x|3.4|to|10|x|4.5|cm}}, while weight varies from {{cvt|43.3|to|60.8|g}}. Most clutches laid in captivity have been infertile, and only four successful breedings have been documented thus far. Hatchlings are about {{cvt|18|in|order=flip}} long and weigh around {{cvt|56|g}}. Like those of many other monitors, hatchling crocodile monitors are more colourful than adults and feed primarily on insects and small reptiles.{{cite book|author=Gressitt, J. L. |title=Biogeography and Ecology of New Guinea |publisher=W. Junk |location=Hague |year=1982 |volume=2 |pages=803–813 |isbn=978-90-6193-094-5}}

Varanus salvadorii is currently protected under the CITES Appendix II,{{cite web |url=http://www.cites.org/eng/app/appendices.shtml |title=Appendices I, II and III |access-date=2008-11-08}} which requires an exportation permit for international trade. It is not listed as a threatened species on the IUCN Red List or on the Endangered Species Act.{{cite web |title=Crocodile Monitor |work=Seaworld |url=http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/crocodile-monitor.htm|access-date=2008-12-07 |archive-date=2007-12-14|archive-url=https://web.archive.org/web/20071214161143/http://www.seaworld.org/animal-info/animal-bytes/animalia/eumetazoa/coelomates/deuterostomes/chordata/craniata/reptilia/squamata/crocodile-monitor.htm|url-status=dead}} It faces threats from deforestation and poaching, as it is hunted and skinned by native peoples, who consider the monitor an evil spirit that "climbs trees, walks upright, breathes fire, and kills men", to make drums.

In 2008, 52 individuals were maintained at 17 zoological parks in the United States, and an unknown number in private collections.{{cite web |title=New Guinea Crocodile Monitor |publisher=Central Florida Zoo and Botanial Gardens |url=http://www.centralfloridazoo.org/our-animals/new-guinea-monitor.shtml |access-date=2008-08-21 |archive-url=https://web.archive.org/web/20080528025013/http://www.centralfloridazoo.org/our-animals/new-guinea-monitor.shtml |archive-date=May 28, 2008}}

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• [https://web.archive.org/web/20081004211439/http://www.honoluluzoo.org/crocodile_monitor.htm Honoluluzoo.org]

{{Varanoidea}}

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Category:Varanus

Category:Monitor lizards of New Guinea

Category:Reptiles of Western New Guinea

Category:Reptiles of Papua New Guinea

Category:Endemic fauna of New Guinea

Category:Reptiles described in 1878

Category:Taxa named by Wilhelm Peters

Category:Taxa named by Giacomo Doria

Category:Apex predators