The Argus monitor (Varanus panoptes) is an intriguing and active lizard that demands specific care and attention to thrive in captivity. Endemic to the southern coastal, grass, riparian, and woodland habitats of the island of New Guinea, both Indonesian and Papua New Guinea countries, and some islands of the Torres Straits, understanding their natural environment is key to replicating suitable conditions in a vivarium. This article will delve into the essential aspects of Argus monitor diet and care, providing a comprehensive guide for enthusiasts and experienced keepers alike.
Natural Habitat and Subspecies
The Argus monitor's natural range extends across diverse habitats. The subspecies horni is replaced by V. p. panoptes in Australia, ranging from the Cape York peninsula of Queensland and going west across the top end of the continent into Western Australia province. A third subspecies, V. p. rubidus, is exclusively found in Western Australia, distinguished by its reddish coloration and high-contrast spotting.
Physical Characteristics and Growth
Newly born neonates typically measure 10 to 12 inches in length and exhibit rapid growth. Adults display sexual dimorphism, with males often reaching a total length of 4½ to 5 feet. Male Argus monitors are generally more robustly built than females, possessing more powerful, bulky front legs. Baby Argus monitors boast brighter colors and patterns compared to their adult counterparts.
Housing
Given that an adult male Argus monitor can reach up to 5 feet in total length, appropriate caging is paramount. Constructing a custom vivarium no smaller than 8 feet in length by 4 feet in width is generally recommended. A height of at least 5 feet is advisable, allowing for 2 feet of substrate at the bottom.
Enclosure Construction and Alternatives
Plywood and wooden support beams are suitable materials for constructing Argus monitor cages. An alternative design involves using a metal cattle watering trough with a wooden box constructed over it. A pre-framed window or custom glass sliders can be inserted into the wooden top portion for enclosure access.
Read also: Water Monitor Feeding Habits
Substrate
Argus monitors are adept diggers, creating tunnels and refugia within the substrate. Suitable substrate options include cypress mulch chips, pure sand, topsoil, plantation soils, and coconut husk/coir byproducts. A preferred mix consists of "diggable" sandy soil found outside combined with 25 to 50 percent coconut coir. The coir enhances humidity retention and facilitates the creation of non-collapsing burrow systems. This coir and sand mixture will not stain a lizard’s skin, either, so the animals look nice in their cages under high-quality lighting. Avoid commercial potting soils due to potential caustic additives like nitrogen and time-released fertilizer spheres, which can be harmful and stain the lizards' skin.
Temperature Gradient and Lighting
An Argus monitor cage should maintain a temperature gradient, with an air temperature of 75 degrees Fahrenheit on the cool end and 100 degrees on the warm side. A basking temperature of approximately 115 degrees directly beneath a basking light is essential, as indicated by a thermometer. When using a non-contact infrared temp gun, aim for a reading of 125 to 135 degrees.
Due to the size of adult Argus monitors, using multiple lamps to create a basking area is preferable to a single lamp. A lizard exceeding 4 feet in length (with a 2-foot snout-to-vent length) may risk skin burns if exposed to a single spotlight with a narrowly focused cone of light and heat for extended periods.
The necessity of UV-producing lights in monitor lizard keeping remains a topic of debate. Monitors have been successfully raised and reproduced using simple incandescent lighting and a proper diet of whole-prey items supplemented with vitamins and minerals.
Humidity and Water
A large tub or pool for swimming and soaking is highly beneficial for Argus monitors. While they can tolerate a range of humidity levels, a more humid environment promotes easier shedding and overall well-being. Maintaining a relative humidity of 70 to 80 percent mid-enclosure is generally acceptable. Avoid housing Argus monitors in fish tanks with screen lids and overhead heat sources, as this can create a desiccating effect.
Read also: Ackie Monitor: Diet and Care
Diet and Feeding
Argus monitors readily associate their keeper with food. They are intelligent animals with a relatively high metabolism. Typical dietary items include insects such as crickets or super worms, pre-killed and thawed mice of the proper size, day-old chicks, fish, crayfish, and most other whole-animal prey items. Whole prey items are considered superior to feeding strips of meat, eggs, and organ meat, which are often high in phosphorus and lack essential nutrients.
Behavior and Temperament
The Argus monitor is an active and often defensive species. Defensive individuals may exhibit "tripodding," standing on their hind legs and tails while inflating their throat to appear larger and more formidable. They may also emit a long, slow, deep hissing noise as a warning.
While Argus monitors typically do not bite out of fear, caution is advised, especially during feeding. Some individuals, particularly older males, may tolerate handling and interaction, but this is not a universal trait. Like most monitor lizards, Argus monitors generally dislike being subdued and held.
Read also: Savannah Monitor Feeding