Yellow-spotted monitor

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Yellow-spotted monitor
ArgusMonitorCincinnati.jpg
A yellow-spotted monitor at the Cincinnati Zoo and Botanical Garden
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Varanidae
Genus: Varanus
Subgenus: Varanus
Species:
V. panoptes
Binomial name
Varanus panoptes
(Storr, 1980)
Subspecies
  • V. p. panoptes
  • V. p. rubidus
  • V. p. horni

The yellow-spotted monitor [1] [2] [3] (Varanus panoptes), also known as the Argus monitor, [4] is a monitor lizard found in northern and western regions of Australia and southern New Guinea. [1] [2]

Contents

Taxonomy

The first description of the species was provided in a revision of the varanids of Western Australia, where the family is represented by diverse taxa in a wide variety of habitats. Early collections and descriptions of the region's species have historically been uncertain, leading the ICZN to issue an opinion that related to this taxon. [5] A third subspecies was published in 1988, based on specimens from southern New Guinea. The describing author discovered that the specimen selected as the type of Varanus gouldii was in fact assignable to this species, recently described by reptile specialist Glenn Storr. By issuing an opinion on the various taxonomic considerations, the voting members conserved the name published with John Edward Gray's description and stabilised the nomenclature of this species name. [6]

Three subspecies are recognised by the Australian Faunal Directory [3] and the Reptile Database: [2]

The epithet panoptes was inspired by a mythological figure with one hundred eyes, the protector of Princess Io named Argus Panoptes. [7] The species may be referred to as the floodplains goanna in the northern regions of Australia. [6]

Description

Juvenile Varanus panoptes (15848624016) 2.jpg
Juvenile

A ground-dwelling species of Varanus , it somewhat resembles the widespread sand goanna (Varanus gouldii). Large, dark spots appear in rows along its back, becoming especially distinct at the center of the back where they are interspersed with smaller and paler spots. Bands of color occur toward the tip of the tail. The overall coloration is brownish in the nominate subspecies, V. panoptes panoptes, and reddish in V. panoptes rubidus. [7]

Yellow-spotted monitor (left), lace monitor (right) Argus Monitor and Lace Monitor.jpg
Yellow-spotted monitor (left), lace monitor (right)

The yellow-spotted monitor displays great sexual dimorphism, with the female reaching an average total length of three feet (90 cm), while the male reaches an average of 4–5 feet (120–150 cm). [9] The largest specimens can have a length in 1.6 m (5 ft 3 in) and a mass in 7 kg (15 lb). [10] [11] It's the third largest lizard in Australia, after perentie and lace monitor. The larger subspecies is V. panoptes panoptes and the smaller one is V. panoptes horni. It is a reasonably lean monitor and does not put on the bulk that other monitors in Africa and Asia do. Most Varanus panoptes are yellow in color, with a background of brown or dark tan, but their color often varies on an individual basis or on their place of origin.

Breeding

In Arnhem Land, they lay 6 to 13 eggs between January and February. [8] Due to similar genetic structures, the yellow-spotted monitor is able to naturally hybridise with the Gould's monitor with a stable hybrid zone.

Behavior

Yellow-spotted monitor "tripod" stance Monitor1.jpg
Yellow-spotted monitor "tripod" stance

Varanus panoptes is a versatile predator and inhabits a large variety of biomes and habitats. They are primarily terrestrial, meaning they spend a great deal of time on the ground. This species is an avid digger and will dig large burrows or take over an already existing burrow, where they spend a sizable portion of their time. Despite this, they will eagerly forage in trees and in the water. These large lizards are quite fast and will run up to 100 meters away to the nearest tree or burrow when they are chased. Varanus panoptes is riparian in habits and as such, it can usually be found around a permanent source of water. Varanus panoptes will often "tripod" in captivity and in the wild, raising up on their hind legs and supporting themselves with their tail. This unusual behavior is used to spot potential prey or enemies from a distance or when they are threatened. They exhibit this behavior regularly in captivity. This habit provides them a unique characteristic that separates them from most other monitors.

Its prey consists of almost anything that it can overpower. This includes fish, crabs, small birds, rodents, insects and even other monitors. They hunt for prey by keying in on movement, chasing it down and overpowering it. In captivity, this monitor has been observed swinging rodent prey around rapidly by the tail in what appears to be an attempt to stun the animal, before biting at the prey's neck. Varanus panoptes frequently preys on the dwarf monitors that it shares its range with. Spiny-tailed goannas and Kimberley rock monitors are eaten regularly. Varanus panoptes have great senses, with smell being the most acute. Like all monitors, Varanus panoptes has a forked tongue and a vomeronasal organ in the roof of its mouth. It uses this organ in the same manner as snakes and other varanids do and can often be seen flicking their tongues in search of a meal.

Recent studies suggest that the infestation of cane toads, a novel and toxic species, has severely damaged the population structure of Varanus panoptes within the Top End. It is estimated that numbers have dropped by as much as 90% in many areas. [12]

In captivity

Many individuals of this species are captive bred as a conservation effort against poisoning from the cane toad infestation of the species’ native range and as exotic pets. Varanus panoptes are fed insects, fish and mice. V. panoptes are husky lizards that can be a challenge to physically handle. They do not like to be restrained, and can use their sharp claws in their attempts to squirm free. If left to wander freely on open ground, their ability to suddenly flee makes escape likely. [4] V. panoptes prefer to bask each morning and return to bask as needed to maintain optimal body temperatures at 80 to 90 °F (26.7 to 32.2 °C). Night-time temperatures may drop 20 °F (11.1 °C) or more if the opportunity to warm up the next day exists.

Related Research Articles

Varanidae Family of lizards

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. Varanus includes the Komodo dragon, crocodile monitor, savannah monitor, the goannas of Australia and Southeast Asia, and various other species with a similarly distinctive appearance. Their closest living relatives are the anguid and helodermatid lizards.

Monitor lizard Genus of reptiles

Monitor lizards are lizards in the genus Varanus. 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.

<i>Megalania</i> Largest species of lizard (extinct)

Megalania is an extinct species of giant monitor lizard, part of the megafaunal assemblage that inhabited Australia during the Pleistocene. It is the largest terrestrial lizard known to have existed, reaching an estimated length of 3.5 to 7 metres, and weighing between 97–1,940 kg (214–4,277 lb), but the fragmentary nature of known remains make estimates highly uncertain. Megalania is thought to have had a similar ecology to the living Komodo dragon. The youngest fossil remains of giant monitor lizards in Australia date to around 50,000 years ago. The first indigenous settlers of Australia might have encountered Megalania, and been a factor in their extinction.

Goanna Several species of reptiles

A goanna is any one of several species of lizards of the genus Varanus found in Australia and Southeast Asia.

Argus Panoptes Giant in Greek mythology

Argus Panoptes or Argos is a many-eyed giant in Greek mythology.

Perentie Species of lizard

The perentie is the largest monitor lizard or goanna native to Australia. It is one of the largest living lizards on earth, after the Komodo dragon, Asian water monitor, crocodile monitor, and intersecting by size with Nile monitor. Found west of the Great Dividing Range in the arid areas of Australia, it is rarely seen, because of its shyness and the remoteness of much of its range from human habitation. The species is considered to be a least-concern species according to the International Union for Conservation of Nature.

Sand goanna Species of lizard

The sand goanna is a species of large Australian monitor lizard, also known as Gould's monitor, sand monitor, or racehorse goanna.

Mangrove monitor 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.

Rock monitor Species of reptile

The rock monitor is a species of monitor lizard in the family Varanidae. The species is endemic to Central, East, and southern Africa. It is the second-longest lizard found on the continent, and the heaviest-bodied; locally, it is called leguaan or likkewaan.

The Pilbara monitor, also known commonly as Bush's monitor, Bush's pygmy monitor, and the Pilbara mulga goanna, is a species of monitor lizard in the family Varanidae. The species is endemic to Australia.

Rosenbergs monitor 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.

Blue-tailed monitor 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.

The canopy goanna, Keith Horne's monitor, blue-nosed tree monitor, or Nesbit River monitor is a species of monitor lizards native to northeast Australia. It is a member of the Varanus prasinus species group.

Finsch's monitor is a species of monitor lizard in the family Varanidae. The species is found in New Guinea and Australia.

Kings monitor Species of lizard

Kings' monitor, also known commonly as Kings' goanna, Kings' rock monitor and pygmy rock monitor, is a small species of monitor lizard in the family Varanidae. The species is native to Australia.

The Rennell Island monitor is a species of monitor lizards found in the Solomon Islands archipelago. It is also known as the Hakoi Monitor. It belongs to the subgenus Euprepiosaurus along with the canopy goanna, the peach-throated monitor, Kalabeck's monitor, and others.

Mitchells water monitor 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 Dampier Peninsula monitor or Dampier Peninsula goanna, described in 2014, is the smallest known species of monitor lizard, growing up to 16.3 grams with a length of almost 23 cm and a SVL of 116 mm. It is believed to live only on the Dampier Peninsula of the Kimberley region north of Broome and Derby in Western Australia. It is highly active, making it difficult to photograph in the wild. It has short legs, an elongate body, a reddish-brown back with widely scattered black spots and "a ridged, circular and short prehensile tail."

"sparnos is Greek for 'rare' or 'scarce' in reference to this species' isolation and small range on the Dampier Peninsula. Latinised to sparnus, and used as an adjective".

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

Storr's monitor is a species of monitor lizard in the family Varanidae. The species is endemic to Australia.

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

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

References

  1. 1 2 3 4 Shea, G.; Allison, A.; Parker, F.; Tallowin, O.; Doughty, P. (2018). "Varanus panoptes". IUCN Red List of Threatened Species . 2018: e.T42485740A42485745. doi: 10.2305/IUCN.UK.2018-1.RLTS.T42485740A42485745.en . Retrieved 19 November 2021.
  2. 1 2 3 Varanus panoptes at the Reptarium.cz Reptile Database. Accessed 8 December 2020.
  3. 1 2 Australian Biological Resources Study (16 August 2012). "Subspecies Varanus panoptes Storr, 1980". Australian Faunal Directory. Canberra, Australian Capital Territory: Department of the Environment, Water, Heritage and the Arts, Australian Government. Retrieved 11 July 2019.
  4. 1 2 Burokas, Justin. "An Owner's Guide To The Argus Monitor". Reptiles Magazine. Retrieved 3 September 2017.
  5. ↑ Shea, G.M.; Cogger, H.G. (1998). "Comment On The Proposed Conservation Of The Names Hydrosaurus gouldii Gray, 1838 and Varanus panoptes Storr, 1980 (Reptilia, Squamata) By The Designation Of A Neotype For Hydrosaurus gouldii". The Bulletin of Zoological Nomenclature. 55: 106–111. doi: 10.5962/bhl.part.159 .
  6. 1 2 3 4 5 Pianka, E.R.; King, D.; King, R.A. (2004). Varanoid Lizards of the World. Indiana University Press. pp. 423, 428. ISBN   9780253343666.
  7. 1 2 3 4 Storr, G.M. (1980). "The monitor lizards (genus Varanus Merrem, 1820) of Western Australia". Records of the Western Australian Museum. 8 (2): 237–293.
  8. 1 2 Ehmann, Harald. (1992). Encyclopedia of Australian Animals: Reptiles, p. 152. Angus&Robertson. Pymble, Sydney, Australia. ISBN   0-207-17379-6
  9. ↑ "Argus Monitor". Reptile Range. Retrieved 11 August 2022.
  10. ↑ "Visual Identification Guide for the Monitor Lizard Species of the World (Genus Varanus)" (PDF). Bfn.de.
  11. ↑ Manh, Bui Duc. "Varanoid Lizards of the World". Academia.edu. Retrieved 2016-03-15.
  12. ↑ "Reptile watch". Australian Broadcasting Corporation . 2010-10-15.

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