Varanus brevicauda
The short-tailed pygmy monitor, *Varanus brevicauda*, is the second smallest living monitor lizard globally, reaching a maximum length of 25 cm. This secretive, terrestrial species inhabits central Australia, burrowing in sandy loam and gravel in spinifex-dominated areas. It is a strictly carnivorous diurnal forager, known for its keen senses and bold predatory nature despite its small size.
Key Facts
- ›Second smallest living monitor lizard in the world.
- ›Ranges throughout central Australia in spinifex-dominated arid regions.
- ›Strictly carnivorous, preying on insects, eggs, spiders, scorpions, and small vertebrates.
- ›Diurnal foragers with keen sight and hearing, relying heavily on chemical signals.
- ›Oviparous, with mating occurring in September and October after hibernation.
- ›Listed as 'least concern' by the IUCN, with predation being the main threat.
Short-Tailed Pygmy Monitor
Central Australia, Western Australia, Northern Territory, South Australia, Queensland
Arid Regions, Spinifex Grasslands, Compacted Sandy Loam, Gravel
- Second Smallest Living Monitor Lizard.
- Maximum Adult Length of 25 cm .
- Newly Hatched: 1-2 Inches Total Length, Weighing 1-2 Grams.
- Long Neck, Well-Developed Limbs With Five Toes Each.
- Strong Claws.
- Powerful Tail That Cannot Undergo Autotomy.
- Body Color: Drab Olive To Brown.
- Lighter Ocelli On the Trunk.
- Monomorphic; Sex Is Nearly Impossible To Determine By Outward Appearance.
Insects, Reptile Eggs, Isopods, Spiders, Scorpions, Centipedes, Small Lizards, Frogs, Small Snakes
- Solitary, Avoids Contact With Other Monitors.
- Secretive and Rarely Seen Active Above Ground.
- Active Diurnal Foragers.
- Keen Sense of Sight and Hearing.
- Attains Sensory Information Through Chemical Signals Via Jacobson's Organ.
- Males Engage In Combat For Mating Rights During the Breeding Season.
- Males Wrestle By Raising On Hind Limbs and Balancing On Tails.
Birds of Prey, Dingoes, Feral Cats, Feral Dogs, Owls, Certain Snakes, Introduced Red Foxes, Larger Monitor Species
Predation By Larger Animals
About Varanus brevicauda
Short-tailed Pygmy Monitor (Varanus brevicauda)
The short-tailed pygmy monitor, scientifically known as Varanus brevicauda, holds the distinction of being the second smallest living monitor lizard in the world. These diminutive reptiles are characterized by their secretive nature and a maximum adult length of approximately 25 centimeters (8 inches). They are primarily found in the arid interior of central Australia, inhabiting areas dominated by spinifex grass, where they burrow into compacted sandy loam and gravel.
Distribution and Habitat
The distribution of Varanus brevicauda spans a significant portion of central Australia, extending from the western coast of Western Australia eastward through the interior of the Northern Territory, and south into northwestern South Australia and western Queensland. Their preferred habitat consists of arid regions, specifically those with the presence of spinifex grasses, which form dense clumps providing suitable cover and burrowing substrate.
Physical Characteristics
As the smallest of the Varanid lizards, the short-tailed pygmy monitor possesses a long neck, well-developed limbs with five toes on each, and strong claws. Its tail is powerful but lacks the ability to undergo autotomy, meaning it cannot be shed. The body coloration typically ranges from a drab olive to brown, often adorned with lighter ocelli (eyespots) on the trunk. The species is monomorphic, making it nearly impossible to distinguish between males and females based on external appearance.
Behavior and Diet
These monitors are solitary by nature, generally avoiding interaction with other individuals, particularly larger ones that could pose a predatory threat. Despite their small size and burrowing habits, it is not uncommon to find dense populations in localized areas. Varanus brevicauda is a highly active diurnal forager, relying on its keen sense of sight and hearing, as well as chemical signals detected by the Jacobson's organ, for navigation and recognition. Their diet is strictly carnivorous, encompassing a variety of prey such as insects, reptile eggs, spiders, scorpions, small lizards, and occasionally frogs and snakes. They are noted for being bold and fierce predators relative to their size.
Reproduction
The short-tailed pygmy monitor is oviparous, reproducing through internal fertilization. The mating season occurs in September and October, following a period of hibernation. Eggs typically hatch by February. Clutch sizes usually consist of two to three eggs, though in some coastal regions, up to five eggs may be laid. Notably, reproduction is suppressed in dry years when food resources are scarce.
Conservation Status
The International Union for Conservation of Nature (IUCN) lists the short-tailed pygmy monitor as 'least concern.' The primary threat to the species' population is predation by a range of animals, including birds of prey, dingoes, feral cats and dogs, owls, various snakes, introduced red foxes, and potentially larger monitor species.
Source: Wikipedia ↗
Frequently Asked Questions
What is the maximum size of the short-tailed pygmy monitor?
The short-tailed pygmy monitor is the second smallest living monitor lizard and reaches a maximum adult length of about 25 cm (8 inches). Newly hatched individuals are much smaller, measuring only 1 to 2 inches in total length.
Where does the short-tailed pygmy monitor live?
This species is found throughout central Australia, extending from the coast of Western Australia across the interior of the Northern Territory, and from northwestern South Australia into western Queensland. They prefer arid regions with spinifex grass.
What does the short-tailed pygmy monitor eat?
The short-tailed pygmy monitor is strictly carnivorous. Its diet includes insects like grasshoppers and beetles, reptile eggs, isopods, spiders, scorpions, centipedes, small lizards, and occasionally frogs and small snakes.
How does the short-tailed pygmy monitor reproduce?
It is an oviparous species, meaning it lays eggs. Mating typically occurs in September and October after hibernation, with eggs hatching by February. Clutch sizes usually range from two to three eggs, but can be up to five in some coastal areas.
What are the main threats to the short-tailed pygmy monitor?
The primary threat to the short-tailed pygmy monitor is predation by larger animals. This includes birds of prey, dingoes, feral cats and dogs, owls, certain snakes, introduced red foxes, and potentially larger monitor lizard species.
Is the short-tailed pygmy monitor active at night?
No, the short-tailed pygmy monitor is a diurnal species. It is described as a very active diurnal forager, meaning it is primarily active and hunts during the daytime.
Related Lizards
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