INTRODUCTION

Blue-tongued skinks (Tiliqua spp.) are terrestrial lizards found throughout Australasia and Indonesia. Different species inhabit a range of environments including open woodland, forest–field margins and semi-desert habitats. The species most commonly kept in captivity include Tiliqua gigas (New Guinea Blue-tongued Skink), Tiliqua scincoides scincoides (Eastern or Common Blue-tongued Skink) and Tiliqua scincoides intermedia (Northern Blue-tongued Skink).

These lizards are robustly built with broad, blunt triangular heads, short limbs and the characteristic deep blue tongue used as a threat display. Adults typically measure 50–60 cm in length and may live up to 20 years in captivity.

Blue-tongued skinks are considered rewarding pets due to their hardiness and engaging behaviour, although improper trade and wild collection remain a concern. They should only be kept by knowledgeable and responsible keepers.

CAPTIVE HUSBANDRY

VIVARIUM

Blue-tongued skinks require a large, secure vivarium providing a suitable temperature gradient and multiple hiding areas. Environmental monitoring is essential to ensure correct temperature and humidity levels for the species. Spot-cleaning should be performed regularly, and the vivarium should be fully cleaned and disinfected approximately every two months.

Suitable substrates exclude materials that may be swallowed, such as sand, bark, wood chips or corn cobs, due to the risk of fatal gastrointestinal impactions. Newspaper is simple and easily replaced. Logs, rocks or purpose-built hides should be provided for shelter and security.

LIGHTING

Blue-tongued skinks require UVB lighting to support vitamin D3 synthesis and calcium metabolism. Natural sunlight is ideal but impractical in the UK climate. High-quality UVB sources such as Reptisun, Iguana Light or Life-Glo are suitable alternatives. UVB bulbs must be replaced every 6–9 months as their output declines. A 12-hour light/dark cycle should be provided as these lizards are diurnal.

TEMPERATURE AND HUMIDITY

The preferred optimum temperature zone (POTZ) is 25–34°C. A basking site of 30–35°C should be available for 12 hours per day. The remainder of the enclosure must provide a gradient from 30–35°C at the warm end to around 24°C at the cool end. Night-time temperatures may drop slightly but should not fall below 16°C (20°C for juveniles).

A gradient can be created using a heat mat under or on the side of the enclosure, or with ceramic heaters, spot bulbs or power plates. All internal heaters must be guarded to prevent burns. A basking lamp is required regardless of other heating methods. A thermostat is strongly recommended to regulate heat sources. Hot rocks should not be used.

Humidity should be maintained at 20–30%, with access to a slightly more humid area during shedding. A simple humidity chamber can be created using a plastic tub filled with damp moss, vermiculite or paper towels. The vivarium should be misted at least once daily. A shallow water dish should be available and cleaned daily.

DIET AND SUPPLEMENTATION

Blue-tongued skinks are omnivores with a diet based largely on insects and plant material. Suitable insect prey includes crickets, mealworms, locusts, cockroaches and waxworms. Adults may occasionally be fed pinkie mice. Some keepers offer dog food as part of the diet, although it should not be the primary food source.

Plant matter should make up approximately 25% of the diet and be offered daily. Vegetables should be finely chopped or grated and well mixed. Suitable vegetables include watercress, mustard cress, parsley, dandelion, clover, turnip greens, collard greens, endive, Chinese leaves, kohlrabi, escarole, carrot tops, green beans, peas, mange-tout, bean sprouts, grated carrot, sweet potato, peppers and sweetcorn.

Adults should be fed every one to two days; juveniles should be fed twice daily with smaller prey items. Cooling crickets in the fridge briefly can slow them down for easier capture. Uneaten insects should be removed to prevent injury.

FOOD DUSTING AND VITAMIN SUPPLEMENTATION

To ensure an appropriate calcium-to-phosphorus ratio, feeder insects must be gut-loaded for 48 hours using products such as Bug-Grub (Vetark). Prey should be dusted with a high-calcium supplement such as Nutrobal (Vetark). Juveniles require daily dusting, whereas adults may be supplemented weekly.