Roughneck monitor

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Rough-necked monitor
20230521 Varanus rudicollis.jpg
CITES Appendix II (CITES) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Varanidae
Genus: Varanus
Subgenus: Soterosaurus
Species:
V. rudicollis
Binomial name
Varanus rudicollis
(Gray, 1845) [3]

The black rough-necked monitor (Varanus rudicollis) is a species of monitor lizard found in Southeast Asian countries of Thailand, Burma, and Malaysia. It is also found in Indonesia on Sumatra and islands of the Riau Archipelago [4] It is sometimes known simply as the roughneck monitor. [5] In Thailand is called h̄èā cĥāng (Thai : เห่าช้าง; "elephant bark"). [6]

Contents

The habitat of Varanus rudicollis is limited to primary and secondary rainforest and mangrove swamps. [7] In the wild the black rough-necked monitor is very rarely seen, but whether this is because of its rarity or its very secretive behavior is uncertain. [3] They are often kept successfully in captivity, but have a shy disposition. [3] [8]

This species is most closely related to its sister group, the water monitor species complex (e.g., the Asian water monitor) which are also in the subgenus Soterosaurus , having split from them 14 million years ago in the middle Miocene. [9] [10]

Description

Hatchling Varanus rudicollis 8 days old copy.png
Hatchling

The black roughneck is a medium to large monitor. It usually reaches an average adult size of 3–4 ft. (90–120 cm), with a maximum length of 5 feet (150 cm), reported. [8] The black rough-necked monitor can be easily recognized by large pointed scales adorning the necks of adults. [4] They are a gracile, long-bodied lizard with a prominently pointed snout. Black roughnecks are known for their very calm temperament, rarely biting or tail whipping in captivity. When threatened they prefer to escape, urinate or defecate, puff up their throats or “go necrotic” by closing their eyes as if playing dead.

Diet habits

Adult male Adult male Varanus rudicollis.png
Adult male

The dietary habits of black rough-necked monitors have been the subject of various studies. Early research by Schnider (in Werner 1900) found insects in specimen from Sumatra. Mertens (1942) suggested that ants and possibly termites were a significant part of their diet, collected using their tongue. Auffenberg (1988) supported this by discovering termites, large stick insects, and tree centipedes in specimens from Malaysia. Brandenberg (1983) found a stomach full of large cockroaches and grasshoppers in one individual, while another from Surat Thani in Thailand had a stomach full of crabs (Nabhitabhata, pers. comm.). Further research by Losos and Greene (1988) revealed that the diet of V. rudicollis may include frogs and their eggs, spiders, scorpions, crabs, cockroaches, beetles, and orthopterans. [11]

These monitors may remain active throughout the year, with their presence most noticeable during months of heavy rainfall

Lifespan

The known lifespan of black rough-necked monitor is about 10–20 years in captivity. [8]

Related Research Articles

<span class="mw-page-title-main">Monitor lizard</span> Genus of reptiles

Monitor lizards are lizards in the genus Varanus, the only extant genus in the family Varanidae. They are native to Africa, Asia, and Oceania, and one species is also found in the Americas as an invasive species. About 80 species are recognized.

<span class="mw-page-title-main">Nile monitor</span> Species of lizard

The Nile monitor is a large member of the monitor family (Varanidae) found throughout most of Sub-Saharan Africa, particularly in drier regions, and along the Nile River and its tributaries in East Africa. Additionally, there are modern, invasive populations in North America. The population found in West African forests and savannahs is sometimes recognized as a separate species, the West African Nile monitor. While it is dwarfed by its larger relatives, such as the Komodo dragon, the Asian water monitor or the crocodile monitor, it is still one of the largest lizards in the world, reaching Australia’s perentie in size. Other common names include the African small-grain lizard, as well as iguana and various forms derived from it, such as guana, water leguaan or river leguaan.

<span class="mw-page-title-main">Bengal monitor</span> Species of lizard

The Bengal monitor, also called the Indian monitor, is a species of monitor lizard distributed widely in the Indian subcontinent, as well as parts of Southeast Asia and West Asia.

<span class="mw-page-title-main">Asian water monitor</span> Species of lizard

The Asian water monitor is a large varanid lizard native to South and Southeast Asia. It is widely considered to be the second-largest lizard species, after the Komodo dragon. It is distributed from eastern and northeastern India and Bangladesh, the Andaman and Nicobar Islands, Sri Lanka, through southern China and Hainan Island in the east to mainland Southeast Asia and the islands of Sumatra, Borneo, Java, Lombok, the Riau Archipelago, Sulawesi. It is one of the most widespread monitor lizards.

<span class="mw-page-title-main">Lace monitor</span> Species of lizard

The lace monitor, also known as the tree goanna, is a member of the monitor lizard family native to eastern Australia. A large lizard, it can reach 2 metres (6.6 ft) in total length and 14 kilograms (31 lb) in weight. The lace monitor is considered to be a least-concern species according to the International Union for Conservation of Nature.

<span class="mw-page-title-main">Black tree monitor</span> Species of reptile

The black tree monitor or Beccari's monitor is a species of lizard in the family Varanidae. The species is a relatively small member of the family, growing to about 90–120 cm (35–47 in) in total length. V. beccarii is endemic to the Aru Islands off New Guinea, living in an arboreal habitat. The skin color of adults is completely black, to which one common name refers.

<span class="mw-page-title-main">Savannah monitor</span> Species of lizard

The savannah monitor is a medium-sized species of monitor lizard native to Africa. The species is known as Bosc's monitor in Europe, since French scientist Louis Bosc first described the species. It belongs to the subgenus Polydaedalus.

<span class="mw-page-title-main">Mangrove monitor</span> Species of lizard

The mangrove monitor, mangrove goanna, or Western Pacific monitor lizard is a member of the monitor lizard family with a large distribution from northern Australia and New Guinea to the Moluccas and Solomon Islands. It grows to lengths of 3.5 to 4 ft. It is also known as wbl yb in the Kalam language of Papua New Guinea.

<span class="mw-page-title-main">Emerald tree monitor</span> Species of lizard

The emerald tree monitor or green tree monitor, is a small to medium-sized arboreal monitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, transversedorsal banding. This coloration helps camouflage it in its arboreal habitat. Its color also makes the emerald tree monitor highly prized in both the pet trade and zoos alike.

<span class="mw-page-title-main">Yellow-spotted monitor</span> Species of reptile

The yellow-spotted monitor, also known as the Argus monitor, is a monitor lizard found in northern and western regions of Australia and southern New Guinea.

<span class="mw-page-title-main">Clouded monitor</span> Species of lizard

The clouded monitor is a species of monitor lizard, native to Burma, Thailand and Indochina to West Malaysia, Singapore, Java, Sumatra, and Vietnam. They are excellent tree climbers. It belongs to the subgenus Empagusia along with the Bengal monitor, the Dumeril's monitor and other monitor lizards. It had previously been listed as a subspecies of Bengal monitor by some herpetologists. It is a diurnal monitor.

<span class="mw-page-title-main">Northern Sierra Madre forest monitor</span> Species of lizard

The Northern Sierra Madre forest monitor, also known by the local names bitatawa, baritatawa, and butikaw, is a large, arboreal, frugivorous lizard of the genus Varanus.

<span class="mw-page-title-main">Dumeril's monitor</span> Species of lizard

Dumeril's monitor is a species of lizard in the family Varanidae. The species is endemic to Southeast Asia.

<span class="mw-page-title-main">Marbled water monitor</span> Species of lizard

The marbled water monitor, also known commonly as the Philippine water monitor, is a large species of monitor lizard in the family Varanidae. The species is endemic to the Philippines.

<i>Varanus spinulosus</i> Species of lizard

Varanus spinulosus, the Solomon Island spiny monitor, Isabel monitor, or spiny-neck monitor, is a species of monitor lizard. It is endemic to the Solomon Islands archipelago and is also known from Santa Isabel Island, San Jorge Island and Bourgainville Island.

The Yemen monitor is a species of Varanus that lives in Yemen and southwestern Saudi Arabia.

<i>Varanus <span style="font-style:normal;">(</span>Odatria<span style="font-style:normal;">)</span></i> Subgenus of reptiles

Odatria, commonly known as dwarf monitors, consists of small monitor lizards found in Australia and Indonesia. Species in this subgenus include the smallest monitor species in the world, the tiny 16 gram Dampier Peninsula monitor, but also includes some more medium sized species such as the 240 gram black-palmed rock monitor.

<i>Varanus <span style="font-style:normal;">(</span>Empagusia<span style="font-style:normal;">)</span></i> Subgenus of lizards

Empagusia is a subgenus of monitor lizards in South to Southeast Asia, which includes medium to large species.

<i>Varanus</i> (Soterosaurus) Subgenus of reptiles

Soterosaurus is a subgenus of monitor lizards commonly known as Southeast Asian water monitors. Most species are endemic to the Philippines, but black rough-necked monitors, Asian water monitors, and Togian water monitors can be found elsewhere in Southeast Asia.

References

  1. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  2. Phimmachak, S.; Cota, M.; Grismer, L.; Quah, E.; Iskandar, D.; Wogan, G.; Arida, E. (2021). "Varanus rudicollis". IUCN Red List of Threatened Species . 2021: e.T83778529A83778660. Retrieved 19 November 2021.
  3. 1 2 3 "Monitor-lizards.net". Archived from the original on 2010-05-19.
  4. 1 2 "Indonesiatraveling.com".
  5. JCVI.org
  6. "อ.เจษฎา เร่งแจง เห่าช้าง เป็นสัตว์กลุ่มตะกวด ไม่ใช่งู-ไม่มีพิษ". Kapook.com (in Thai). 12 June 2015. Retrieved 16 June 2016.
  7. Mampam.com
  8. 1 2 3 "Herpcenter.com". Archived from the original on 2009-10-31.
  9. Welton, Luke J.; Wood, Perry L.; Oaks, Jamie R.; Siler, Cameron D.; Brown, Rafe M. (2014-05-01). "Fossil-calibrated phylogeny and historical biogeography of Southeast Asian water monitors (Varanus salvator Complex)". Molecular Phylogenetics and Evolution. 74: 29–37. doi:10.1016/j.ympev.2014.01.016. ISSN   1055-7903. PMID   24486878.
  10. Brennan, Ian G.; Lemmon, Alan R.; Lemmon, Emily Moriarty; Portik, Daniel M.; Weijola, Valter; Welton, Luke; Donnellan, Stephen C.; Keogh, J. Scott (2020-02-03), Phylogenomics of monitor lizards and the role of competition in dictating body size disparity, doi:10.1101/2020.02.02.931188 , retrieved 2024-05-18
  11. Daniel Bennett. 1995. A Little Book of Monitor Lizards. Viper Press U.K.

Further reading