Dumeril's monitor (''Varanus dumerilii'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of lizard in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Varanidae The Varanidae are a family of lizards in the superfamily Varanoidea within the Anguimorpha group. The family, a group of carnivorous and frugivorous lizards, includes the living genus '' Varanus'' and a number of extinct genera more closely rel ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...

Etymology and naming

The specific name, ''dumerilii'', is in honour of the French

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and d ...

André Marie Constant Duméril. In

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

, ''V. dumerilii'' is known by the common name, ''túdtū̀'' (ตุ๊ดตู่), which is an animal that appeared in children's folk songs.

Geographic range

Dumeril's monitor is found in southern

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

and north of the

Isthmus of Kra The Kra Isthmus ( th, คอคอดกระ, ) in Thailand is the narrowest part of the Malay Peninsula. The western part of the isthmus belongs to Ranong Province and the eastern part to Chumphon Province, both in Southern Thailand. The ...

Kanchanaburi Kanchanaburi ( th, กาญจนบุรี, ) is a town municipality (''thesaban mueang'') in the west of Thailand and part of Kanchanaburi Province. In 2006 it had a population of 31,327. That number was reduced to 25,651 in 2017. The town ...

Province in

,Cota M, Chan-ard T, Mekchai S, Laoteaw S (2008). "Geographical Distribution, Instinctive Feeding Behavior and Report of Nocturnal Activity of ''Varanus dumerilii'' in Thailand". ''Biawak'' 2 (4): 152-158. as well as in

Peninsular Malaysia Peninsular Malaysia ( ms, Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), or the States of Malaya ( ms, Negeri-negeri Tanah Melayu; Jawi: نڬري-نڬري تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, ...

, throughout

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and ea ...

, Sumatra,

Riau Riau is a province of Indonesia. It is located on the central eastern coast of Sumatra along the Strait of Malacca. The province shares land borders with North Sumatra to the northwest, West Sumatra to the west, and Jambi to the south. Acco ...

, Bangka–Belitung and other smaller islands of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. www.reptile-database.org

Habitat

The preferred

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of ''V. dumerilii'' is dense evergreen forests with high humidity and mangrove swamps, at altitudes from sea level to .

Diet

''V. dumerilii'' is a crab specialist; however, it has been observed eating

snail A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class G ...

s, other molluscs,

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

eggs,

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, and smaller

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

s. Little is known overall about this species compared to other monitor lizards.

Description

Adult Dumeril's monitors are largely dark brown, with occasional brighter indistinct crossbars. For juveniles the colors and patterns are quite different. "The major color is a dark varnish black which is interrupted by several yellow crossways bars on the back." The head of juveniles is shiny orange-red or sometimes yellow. This juvenile coloration disappears after only 4–8 weeks. Adult Dumeril's monitors can reach up to in total length (including tail) although typical total length is .

Behavior

''V. dumerilii'' is

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

and diurnal.

Reproduction

''V. dumerilii'' is oviparous. Clutch size is 4–23 eggs. Hatchlings have a snout-to-vent length (SVL) of about , and a tail slightly longer than SVL.

Subspecies

There are two described subspecies: *''Varanus dumerilii dumerilii'' *''Varanus dumerilii heteropholis'' Note: Sprackland made ''V. d. heteropholis'' a synonym of ''V. d. dumerilii''. Sprackland RG (1993). "The taxonomic status of the monitor lizard ''Varanus dumerilii heteropholis'' BOULENGER 1892 (Reptilia: Varanidae)". ''Sarawak Museum Journal'' 44 (65): 113-121.

References

*Amer, Sayed A. M.; Kumazawa, Yoshinori (2008). "Timing of a mtDNA gene rearrangement and intercontinental dispersal of varanid lizards". ''Genes Genet. Syst.'' 83: 275–280. * Auffenberg W (1988). ''Gray's monitor lizard''. Gainesville: University of Florida. *Ávalos, J. de; Martínez Carrión, P. (1997). "''Warane'' ". ''Reptilia'' (Münster) 2 (5): 16-21. (in German). * Barbour T (1921). "Aquatic skinks and arboreal monitors". ''Copeia'' 1921 (1): 42-44. * Boulenger GA (1885). ''Catalogue of lizards in the British Museum (Natural History). Second Edition. Volume II ... Varanidæ ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 497 pp. + Plates I-XXIV. (''Varanus dumerilii'', pp. 312–313). *Brandenberg T (1983). ''Monitors in the Indo-Australian Archipelago''. Leiden: E.J. Brill. 121 pp. *Coborn, John (1987). ''Snakes and lizards: Their care and breeding in captivity''. Newton Abbott: David and Charles Publishing. * Cota M, Chan-ard T, Mekchai S, Laoteaw S (2008). "Geographical Distribution, Instinctive Feeding Behavior and Report of Nocturnal Activity of ''Varanus dumerilii'' in Thailand". ''Biawak'' 2 (4): 152-158. * Cox MJ, van Dijk PP, Nabhitabhata J, Thirakhupt K (1998). ''A Photographic Guide to Snakes and other Reptiles of Peninsular Malaysia, Singapore and Thailand''. Ralph Curtis Publishing. 144 pp. *Davis R, Darling R, Darlington A (1986). "Ritualised combat in captive ''V. dumerilii'' ". ''Herpetological Review'' 17 (4): 85-86. *Davis RB, Phillips LG (1991). "A method of sexing Dumeril's monitor ''Varanus dumerili'' ". ''Herp. Review'' 22 (1): 18-19. *Harrison JL, Boo-Liat L (1957). "Monitors of Malaya". ''Malay Nature Journal'' 12 (1): 1-10. * Horn H-G, Schulz B (1977). "Varanus dumerilii, ''wie ihn nicht jeder kennt'' ". ''Das Aquarium'' 11 (9): 37-38. (in German). * Lekagul B (1969). "Monitors of Thailand". ''Conservation News of S.E. Asia'' 8: 31-32. * Losos JB, Greene HW (1988). "Ecological and evolutionary implications of diet in monitor lizards". ''Biological Journal of the Linnean Society'' 35: 379-407. * Mertens R (1942). "''Die Familie der Waranae (Varanidae)'' ". ''Abhandlungen der Senckenberischen Naturforschenden Gesellschaft'' 462; 465; 466. (in German). * Nutphand W (no date). ''The Monitors of Thailand''. Bangkok: Mitphadung Publishing Office. * Pitman CRS (1962). "More snake and lizard predators of birds". ''Bulletin of the British Ornithologists' Club'' 82 (3): 45-55. *Radford L, Payne FL (1989). "The reproduction and management of ''Varanus dumerilii'' ". ''International Zoo Yearbook'' 28: 153-155. *Raven HC (1946). "Predators eating green turtle eggs in the East Indies". ''Copeia'' 1946 (1): 48. * de Rooij N (1915). ''The Reptiles of the Indo-Australian Archipelago''. Leiden: E.J. Brill. * Schlegel H (1839). ''Abbildungen neuer oder unvollständig bekannter AMPHIBIEN, nach der Natur oder dem Leben entworfen herausgegeben und mit einem erläuternden Texte begleitet.'' Düsseldorf: Arnz & Comp. xiv + 141 pp. (''Monitor dumerilii'', new species, p. 78). (in German). * Smith MA (1922). "On a Collection of Reptiles and Batrachians from the mountains of Pahang, Malay Peninsula". ''Journal of the Federated Malay States'' 10: 263-282. (''Varanus dumerilii'', p. 269). *Smith HC (1930). "The monitor lizards of Burma". ''Journal of the Bombay Natural History Society'' 34: 367-373. * Taylor EH (1963). "Lizards of Thailand". ''University of Kansas Science Bulletin'' 44 (14): 687-1077. (''Varanus dumerilii'', pp. 915, 918-920). * Sprackland RG (1976). "Notes on Dumeril's monitor lizard ''Varanus dumerili'' (Schlegel)". ''Sarawak Museum Journal'' 24 (45): 287-291.

External links

Photo of Dumeril's Monitor at Whozoo.org
{{DEFAULTSORT:Dumeril's Monitor Varanus Reptiles of Indonesia Reptiles of Thailand Reptiles of Myanmar Reptiles of Malaysia Reptiles of Borneo Reptiles described in 1839 Taxa named by Hermann Schlegel