Colei Monitor (Varanus colei)

Common Name: Colei Monitor
Scientific Name: Varanus colei
Source: CBID
Adult Size: Typically 80–100cm total length
Native Range: including parts of Papua and surrounding island groups

Enclosure: A custom-built Viperia PVC vivarium sized to suit — use the Vivarium Calculator to spec the right dimensions. This active, semi-arboreal monitor requires a large, well-ventilated enclosure with a deep substrate layer for digging, sturdy climbing branches, secure hides at both the warm and cool ends, and a robust basking platform beneath the heat source.
Heating: Basking spot of 40–45°C, with an ambient (background) temperature of 28–32°C on the warm side and 24–26°C on the cool side; a night-time drop to around 22–24°C is acceptable and natural.
Humidity: Aim for 70–85%, reflecting the humid tropical island environments this species inhabits. Achieve this through regular light misting, a moisture-retaining substrate such as coco fibre or topsoil mix, and a partially covered top or reduced ventilation panel if needed.
UVB: A 12% UVB tube run along most of the vivarium's width, positioned so the animal can bask 25–35cm from the lamp. As a diurnal (active by day), open-habitat basking monitor, V. indicus colei receives intense natural sunlight and requires strong UVB provision in captivity to support vitamin D3 synthesis and long-term bone health.
Diet: Colei monitors are carnivorous and should be offered a varied diet of appropriately sized whole prey items — including mice, chicks, quail, large insects (such as locusts and roaches), and occasional shellfish or whole fish. Juveniles can be fed every 1–2 days; adults every 2–3 days. Prey should be dusted with a quality calcium and vitamin supplement 2–3 times per week.

ABOUT THIS SPECIES

The Colei monitor is a striking species of the wide-ranging Mangrove monitor (Varanus indicus), found across humid tropical island habitats in the western Pacific. These lizards are bold, intelligent, and visually impressive — typically displaying vivid yellow spotting against a dark base colour that makes them one of the more eye-catching monitors available in the hobby.

These are active, curious monitors that reward experienced keepers with genuinely engaging behaviour, though they do require a confident and consistent handler to settle well. They are best suited to keepers who already have some experience with medium to large monitors and can commit to a spacious, carefully maintained setup and a varied, high-quality diet.