Perentie | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Family: | Varanidae |
Genus: | Varanus |
Subgenus: | Varanus |
Species: | V. giganteus |
Binomial name | |
Varanus giganteus (Gray, 1845) | |
Distribution of the perentie | |
Synonyms [2] | |
Hydrosaurus giganteus, Gray |
The perentie (Varanus giganteus) is a species of monitor lizard. It is one of the largest living lizards on earth, after the Komodo dragon, Asian water monitor, and the Crocodile monitor. [3] [4] 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.
Its status in many Aboriginal cultures is evident in the totemic relationships, and part of the Ngiṉṯaka dreaming, as well as bush tucker. It was a favoured food item among desert Aboriginal tribes, and the fat was used for medicinal and ceremonial purposes.
British zoologist John Edward Gray described the perentie in 1845 as Hydrosaurus giganteus, calling it the "gigantic water lizard". [5] George Albert Boulenger moved it to the genus Varanus. [6]
Within the monitor genus Varanus , it lies within the subgenus Varanus. Its closest relatives belong to a lineage that gave rise to the sand goanna and the Argus monitor.
Perenties are the largest living species of lizard in Australia. Perenties can grow to lengths of 2.5 m (8 ft 2 in) and weigh up to 20 kg (44 lb), possibly up to 3 m (9 ft 10 in) and 40 kg (88 lb), making it the fourth-largest extant species of lizard (exceeded in size only by the Komodo dragon, Asian water monitor and crocodile monitor). [7] [8] [9] However, perenties are very lean among large monitors, making it significantly less bulky than the rock monitor at a similar size.
In late 2005, University of Melbourne researchers discovered that all monitors may be somewhat venomous. Previously, bites inflicted by monitors were thought to be prone to infection because of bacteria in their mouths, but the researchers showed that the immediate effects are caused by mild envenomation. Bites on the hand by Komodo dragons (V. komodensis), perenties (V. giganteus), lace monitors (V. varius), and spotted tree monitors (V. scalaris) have been observed to cause swelling within minutes, localised disruption of blood clotting, and shooting pain up to the elbow, which can often last for several hours. [10]
University of Washington biologist Kenneth V. Kardong and toxicologists Scott A. Weinstein and Tamara L. Smith have argued that the suggestion of venom glands "... has had the effect of underestimating the variety of complex roles played by oral secretions in the biology of reptiles, produced a very narrow view of oral secretions and resulted in misinterpretation of reptilian evolution". According to the scientists "... reptilian oral secretions contribute to many biological roles other than to quickly dispatch prey". They concluded, "Calling all in this clade venomous implies an overall potential danger that does not exist, misleads in the assessment of medical risks, and confuses the biological assessment of squamate biochemical systems". [11]
Perenties are found in the arid desert areas of Western Australia, South Australia, the Northern Territory, and Queensland. Their habitats consist of rocky outcroppings and gorges, with hard-packed soil and loose stones.
Perenties generally avoid human contact and often retreat before they are seen. Being able diggers, they can excavate a burrow for shelter in only minutes. Their long claws enable them to climb trees easily. They often stand on their back legs and tails to gain a better view of the surrounding terrain. This behavior, known as "tripoding", is quite common in monitor species. Perenties are fast sprinters and can run using either all four legs or just their hind legs.
Typical of most goannas, the perentie either freezes (lying flat on the ground, and remaining very still until the danger has passed) or runs if detected. If cornered, this powerful carnivore stands its ground and uses its arsenal of claws, teeth, and whip-like tail to defend itself. It can inflate its throat and hiss as a defensive or aggressive display and can strike at opponents with its muscular tail. It may also lunge forward with an open mouth, either as a bluff or attack. The bite of a perentie can do much damage, not only from the teeth but also because of the oral secretions.
The perenties are apex predators that do not have natural predators in their range. [12] They are highly active carnivores that feed on mostly reptiles, small mammals, and less commonly birds such as diamond doves. [13] They hunt live prey, but also scavenge carrion. Reptilian prey includes mostly lizards (such as skinks and agamids) and more seldom snakes, but this species also displays a notable example of intraguild predation, as it eats an unusually large number of other monitor lizard species such as ridge-tailed monitors, black-headed monitors, Gould's monitors, and even Argus monitors. [14] [15] [16] Perenties also eat smaller members of their own species; such is the case of a 2 m (6 ft 7 in) perentie killing and eating a 1.5 m (4 ft 11 in) perentie. [17] Other lizard prey include central bearded dragons and long-nosed water dragons. Coastal and island individuals often eat a large number of sea turtle eggs and hatchlings and hide under vehicles to ambush scavenging gulls. Mammalian prey includes bats, young kangaroos other small marsupials, and rodents. They have also been occasionally seen foraging for food in shallow water. They are able to kill kangaroos and dismember those too large to be swallowed whole using their powerful forelimbs and claws. [18] Although adults feed predominantly on vertebrate prey, young perenties eat mostly arthropods, especially grasshoppers and centipedes. [19] [17] [20]
Prey is typically swallowed whole, but if the food item is too large, chunks are ripped off for ease of consumption. [21]
The perentie can lay its eggs in termite mounds or the soil. [22]
The Komodo dragon, also known as the Komodo monitor, is a large reptile of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant species of lizard, with the males growing to a maximum length of 3 m (9.8 ft) and weighing up to 150 kg (330 lb).
Lizard is the common name used for all squamate reptiles other than snakes, encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The grouping is paraphyletic as some lizards are more closely related to snakes than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon.
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.
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, but the fragmentary nature of known remains make estimates highly uncertain. Recent studies suggest that most known specimens would have reached around 3 m (9.8 ft) or more excluding the tail, while larger individuals would have reached at least over 7 m (23 ft) long.
A goanna is any one of several species of lizard of the genus Varanus found in Australia and Southeast Asia.
Toxicofera is a proposed clade of scaled reptiles (squamates) that includes the Serpentes (snakes), Anguimorpha and Iguania. Toxicofera contains about 4,600 species, of extant Squamata. It encompasses all venomous reptile species, as well as numerous related non-venomous species. There is little morphological evidence to support this grouping; however, it has been recovered by all molecular analyses as of 2012.
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.
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.
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.
The sand goanna, also known commonly as Gould's monitor, the racehorse goanna, and the sand monitor, is a species of large Australian monitor lizard in the family Varanidae.
The crocodile monitor, also known as the Papuan monitor or Salvadori's monitor, is a species of monitor lizard endemic to New Guinea. It is the largest monitor lizard in New Guinea and is one of the longest lizards, verified at up to 255 cm (100 in). Its tail is exceptionally long, with some specimens having been claimed to exceed the length of the Komodo dragon, however less massive.
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.
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.
The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to Varanus and Anguis than Scincus. These lizards, along with iguanians and snakes, constitute the proposed "venom clade" Toxicofera of all venomous reptiles.
The rock monitor is a species of monitor lizard in the family Varanidae. The species is endemic to Sub-Saharan Africa, where, on average it is the largest lizard found on the continent. It is called leguaan or likkewaan in some areas.
The pygmy mulga monitor, also known commonly as Gillen's monitor or just the mulga monitor, is a species of lizard in the family Varanidae. The species is endemic to Australia.
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 the IUCN 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.
Hapturosaurus, sometimes known as the tree monitors, is a subgenus of lizards, consisting of slender-bodied arboreal monitor lizards mostly found in the tropical rainforests of Indonesia and Papua New Guinea.
Varanus, commonly known as true monitors, is one of the 11 subgenera of the genus Varanus. All of its species are found in the Australasian realm, among which are the world's largest lizards.