Rock monitor

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Rock monitor
White-throated Monitor (Varanus albigularis) (5984080381).jpg
A white-throated monitor at Kruger National Park, South Africa
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Varanidae
Genus: Varanus
Subgenus: Polydaedalus
Species:
V. albigularis
Binomial name
Varanus albigularis
(Daudin, 1802) [2] [3]
Synonyms [4]
  • Tupinambis albigularis
    Daudin, 1802
  • Monitor albigularis
    Gray, 1831
  • Varanus albogularis
    A.M.C. Duméril & Bibron, 1836
  • Regenia albogularis
    Günther, 1861
  • Varanus albigularis
    Boulenger, 1885
  • Varanus exanthematicus albigularis
    Schmidt, 1919
  • Varanus albigularis
    Böhme, 1988

The rock monitor (Varanus albigularis) is a species of monitor lizard in the family Varanidae. The species is endemic to Sub-Saharan Africa. It is on average the largest lizard found on the continent, and is locally called leguaan or likkewaan.

Contents

Taxonomy

First described by François Marie Daudin in 1802, [2] V. albigularis has been classified as a subspecies of V. exanthematicus , [5] but has since been declared a distinct species based upon differences in hemipenal morphology. [6] The generic name Varanus is derived from the Arabic word waral ورل, which is translated to English as "monitor". The specific name albigularis comes from a compound of two Latin words: albus meaning "white" and gula meaning "throat".

The subspecies of V. albigularis are:

Description

Varanus albigularis is on average the most massive lizard in Africa, as adult males average about 6 to 8 kg (13 to 18 lb) and females weigh from 3.2 to 5 kg (7.1 to 11.0 lb). [7] [8] [9] Large mature males can attain weights of 15 to 17 kg (33 to 37 lb), which would make it slightly smaller than the Nile monitor by maximum size. [10] It is the second longest African lizard after the Nile monitor. Mature specimens typically measure 0.85 to 1.5 meters (2 ft 9 in to 4 ft 11 in). [8] [10] The head and neck are the same length, and are distinct from each other. [11] The bulbous, convex snout gives an angular, box-like appearance. The forked tongue is pink or bluish, [11] and the body scales are usually a mottled gray-brown with yellowish or white markings. [11] Exceptionally large specimens reach 2 meters (6 ft 7 in) in total length (including tail), with its tail and body being of equal size. [12]

Geographic range and habitat

V. albigularis is found in Central Africa (Democratic Republic of the Congo/Zaire), Southern Africa (Namibia, Botswana, Republic of South Africa, Eswatini, Zimbabwe, Mozambique, Zambia, Angola), the African Great Lakes (Kenya, Uganda, Tanzania), and the Horn of Africa (Ethiopia, Somalia). [11] V. albigularis is found in a variety of dry habitats, including steppes, prairies, and savannahs, but is absent from desert interiors, rainforests, and thick scrub forests. [11]

Diet

V. albigularis are generalists, feeding opportunistically on a broad variety of prey in the wild, such as other lizards, amphibians, birds, snakes, tortoises, eggs and small mammals. [13] [14] Tortoises make up a significant part of their diet, and are swallowed whole due to the hard shell. Otherwise, this species consumes very little vertebrate prey, eating primarily invertebrates, especially millipedes, beetles, molluscs, orthopterans and scorpions. [15] Millipedes for example form nearly a quarter of their diet; the monitors are apparently resistant to its poisonous secretions. They are not averse to occasionally scavenging the corpses of vertebrate prey, even those as large as vervet monkeys, which are sometimes torn to pieces by "death rolling" like a crocodilian prior to consumption. [16] Live vertebrate prey other than tortoises are usually too fast to catch for these monitors, and therefore form very little of their diet. [17] This contrasts with what is often a diet of mostly vertebrates in captivity, such as rodents, poultry or fish. [18]

Predator

Natural predators of adult rock monitors include martial eagles and leopard. [19] [20]

Intelligence

An intelligent lizard, several specimens of V. albigularis have demonstrated the ability to count as high as six in an experiment conducted by Dr. John Philips at the San Diego Zoo in 1999. [21] Philips offered varying numbers of snails, and the monitors were able to distinguish numbers whenever one was missing. [22] [23]

Folklore

People living with the HIV/AIDS virus in Yumbe District of Uganda have been reported injecting themselves with the blood of rock monitors, which they believe to be a cure for the virus. [24] Many are reportedly discontinuing anti-retroviral therapy to pursue this anecdotal treatment. [24]

As a result, V. albigularis is reported to have become an expensive item in the Ugandan black market, selling for more than 175 US$ each. [24]

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.

François Marie Daudin was a French zoologist.

<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 and along the Nile, with invasive populations in North America. The population in West African forests and savannahs is sometimes recognized as a separate species, the West African Nile monitor. It is one of the largest lizards in the world reaching and even surpassing the perentie by 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. A feral population of the lizards, descended from escaped or intentionally released pets, has become established in several locations in Florida.

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

The Bengal monitor, also called the common Indian monitor, is a monitor lizard distributed widely in the Indian Subcontinent, as well as parts of Southeast Asia and West Asia. This large lizard is mainly a terrestrial animal, and its length ranges from about 61 to 175 cm from the tip of the snout to the end of the tail. Young monitors may be more arboreal, but adults mainly hunt on the ground, preying mainly on arthropods, but also taking small terrestrial vertebrates, ground birds, eggs and fish. Although large Bengal monitors have few predators apart from humans who hunt them for meat, younger individuals are hunted by many predators.

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

The desert monitor is a species of monitor lizard of the order Squamata found living throughout North Africa and Central and South Asia. The desert monitor is carnivorous, feeding on a wide range of vertebrates and invertebrates.

<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 one of the most common monitor lizards in Asia, ranging from coastal northeast India, Bangladesh, Sri Lanka, mainland Southeast Asia, and southern China to Indonesian islands where it lives close to water. It is listed as Least Concern on the IUCN Red List. It was described by Laurenti in 1768 and is among the largest squamates in the world.

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

The lace monitor or 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">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.

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

The spiny-tailed monitor, also known as the Australian spiny-tailed monitor, the ridge-tailed monitor the Ackie's dwarf monitor, and colloquially simply ackie monitor, is an Australian species of lizard belonging to the genus of monitor lizards (Varanus).

<span class="mw-page-title-main">White-throated monitor</span> Subspecies of lizard

The white-throated monitor is a lizard found in southern Africa. They are usually gray-brown with yellowish or white markings, and can reach up to 2 metres (6.6 ft) in length. They are found in Southern Africa, northwards to Angola, Zambia, and Mozambique.

<span class="mw-page-title-main">Black-throated monitor</span> Subspecies of lizard

The black-throated monitor is a subspecies of monitor lizard in the family Varanidae. The subspecies is native to Tanzania.

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

The peacock monitor, also known commonly as Auffenberg's monitor, is a species of small monitor lizard in the family Varanidae. The species, which belongs to the subgenus Odatria, is endemic to Rote Island, Indonesia.

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

The Rosenberg's monitor is an Australian species of varanid reptile found in southern regions of the continent. They are large and fast predators with rugged bodies and long tails, having a combined length up to 1.5 metres, that will consume any smaller animal that is pursued and captured or found while foraging. They occur in the Australian Capital Territory, New South Wales, South Australia, Victoria, where it may be rare or locally common, and more frequently observed in Western Australia, where it is sometimes abundant.

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

The blue-tailed monitor, blue-tailed tree monitor or Kalabeck's monitor, is a monitor lizard of the Varanidae family. It belongs to the V. doreanus group of the subgenus Euprepiosaurus.

<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">Mitchell's water monitor</span> Species of lizard

Mitchell's water monitor is a semiaquatic species of monitor lizard in the family Varanidae. The species is native to Australia. The species is native to the Northern regions of Australia, and is on IUCN's Red List as a critically endangered species. They can be distinguished by the orange or yellow stripes along their neck and dark spots along their back. They are mainly carnivorous, and eat small prey such as lizard, birds, and insects.

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

Hapturosaurus, sometimes known as the tree monitors, is a subgenus of lizrads, consisting of slender-bodied arboreal monitor lizards mostly found in the tropical rainforests of Indonesia and Papua New Guinea.

References

  1. Beraduccii, J.; Msuya, C.A.; Howell, K.; Ngalason, W. (2021). "Varanus albigularis". IUCN Red List of Threatened Species . 2021: e.T22473612A22473630. Retrieved 19 November 2021.
  2. 1 2 Daudin FM (1802). Histoire Naturelle, Génerale et Particulière des Reptiles; Ouvrage faisant suite à l'Histoire Naturelle, générale et particulière, composée par LECLERC DE BUFFON, et redigée par C. S. SONNINI, membre de plusieurs Sociétés savantes. Tome Troisième [Volume 3]. Paris: F. Dufart. 452 pp. + Plates I-XLV. (Tupinambis albigularis, new species, pp. 72-75 + Plate XXXII).
  3. "Varanus albigularis ". Integrated Taxonomic Information System . Retrieved 22 August 2008.
  4. 1 2 "Varanus albigularis ". The Reptile Database. www.reptile-database.org.
  5. Laurent RF (1964). "A new subspecies of Varanus exanthematicus (Sauria, Varanidae)". Breviora (199): 1-5. (Varanus exanthematicus ionidesii, new subspecies).
  6. Böhme W (1991). "New finding on the hemipenal morphology of monitor lizards and their systematic implications". Mertensiella2: 42-49.
  7. "White Throated Monitor – Varanus albigularis ". Reptiliana: Ultimate Reptile Resource. March 2008. Retrieved 2013-06-06.
  8. 1 2 "African Savannah Monitor – Varanus exanthematicus albigularis ". WAZA : World Association of Zoos and Aquariums. Retrieved 2013-06-06.
  9. Gardner BR, Barrows MG (2010). "Yolk coelomitis in a white-throated monitor lizard (Varanus albigularis)". Journal of the South African Veterinary Association81 (2): 121-122.
  10. 1 2 "Varanus albigularis ". Monitor-Lizards.net. Archived from the original on 2012-07-31. Retrieved 2013-06-06.
  11. 1 2 3 4 5 Alexander, Graham; Marais, Johan (2008). A Guide to the Reptiles of Southern Africa. South Africa: Struik Publishers. 408 pp. ISBN   978-1-77007-386-9.
  12. Carruthers, Vincent (June 5, 2008). The Wildlife of Southern Africa: The Larger Illustrated Guide to the Animals and Plants of the Region. South Africa: Struik Publishers. 320 pp. ISBN   978-1-77007-199-5.
  13. https://www.researchgate.net/publication/280597661_Varanus_albigularis_-_Diet [ bare URL ]
  14. "Varanus Albigularis".
  15. "Varanus Albigularis".
  16. Krebs, Uwe (January 2019). "Observations and Experiments on "Spinning Behavior" in Varanus albigularis". Biawak. 13 (1): 54–61.
  17. Dalhuijsen, Kim (10 December 2013). "A comparative analysis of the diets of Varanusalbigularis and Varanus niloticus in South Africa". African Zoology. 49 (1): 84–93.
  18. "Black-Throated Monitor 101: Care, Size, Diet & More!". 26 July 2022.
  19. "Eagle Rips Lizard's Eyes Apart As it Tries to Escape". Kruger sighting. September 15, 2020.
  20. Radloff, Frans GT, and Johan T. Du Toit. "Large predators and their prey in a southern African savanna: a predator's size determines its prey size range." Journal of Animal Ecology 73.3 (2004): 410-423.
  21. Pianka, Eric R.; Vitt, Laurie J. (2003). Lizards: Windows to the Evolution of Diversity . Berkeley, Los Angeles, London: University of California Press. 346 pp. ISBN   978-0-520-23401-7.
  22. King, Dennis; Green, Brian (1999). Goannas: The Biology of Varanid Lizards. University of New South Wales Press. ISBN   0-86840-456-X. p. 43.
  23. The Weekend Australian. July 24–25, 1999, p. 12.
  24. 1 2 3 "Ugandans turn to varanid lizard blood for AIDS cure" (PDF). BIAWAK. INTERNATIONAL VARANID INTEREST GROUP. 2 (1). February 2008. Retrieved 2008-08-27.

Further reading