Black Tree Monitor (Varanus beccari)

Common Name: Black Tree Monitor
Scientific Name: Varanus beccari
Source: CBID
Adult Size: Up to 90–110cm total length, with the tail comprising roughly two-thirds of that length
Native Range: Aru Islands, Indonesia

Enclosure: A minimum 120x60x180cm Viperia PVC vivarium — this species is highly arboreal (tree-dwelling) and needs significant vertical height; furnish the enclosure with thick, branching climbing structures, cork bark tubes for shelter, and a deep leaf-litter substrate to retain humidity
Heating: Basking spot of 40-45°C, with an ambient (background) temperature of 28–32°C across the warm side; allow a night-time drop to around 22–24°C
Humidity: 70–90%; achieved through daily misting, a humid substrate mix such as coconut fibre blended with orchid bark, and good-but-controlled ventilation to prevent stagnation
UVB: A 6% UVB tube run along most of the vivarium's width, positioned so the animal can bask at around 20–30cm from the lamp; black tree monitors are diurnal (active by day) and receive meaningful sun exposure in the wild, making quality UVB provision essential for long-term health
Diet: Primarily insects and other invertebrates — feed a varied rotation of locusts, dubia roaches, crickets, and occasional waxworms or mealworms; larger adults can take the occasional pinky mouse as a supplement, though invertebrates should form the bulk of the diet. Juveniles can be fed daily; adults every two to three days. Dust prey with a calcium and vitamin D3 supplement on most feeds

ABOUT THIS SPECIES

The black tree monitor is one of the most visually striking lizards in the hobby — a sleek, jet-black monitor native to the rainforest canopy of the Aru Islands in Indonesia, where it spends the vast majority of its life high off the ground. Its prehensile (gripping) tail, elongated toes, and lightweight build are all adaptations for life in the treetops, and in captivity that same athleticism makes it endlessly fascinating to watch.

These are active, intelligent lizards that can become relatively tolerant of their keeper with consistent, patient handling from a young age, though they are not typically a hands-on species and are best appreciated as a display animal. They suit experienced reptile keepers who are comfortable managing high humidity environments and providing the enriched, vertically spacious setup this species genuinely needs to thrive.