Monitor lizards (Asian water monitor)

Summary

Large Asian water monitor lizards live on Koh Samui near streams, waterfalls and wetlands. They look intimidating but are shy and harmless if left alone.

Details

The Asian water monitor (Varanus salvator) is one of the largest lizards in the world, sometimes reaching two metres, and it lives on Koh Samui, especially near fresh water: streams, the Na Muang waterfall area, ponds and mangroves. Local wildlife guides class them as common. Monitors are strong swimmers and often seen swimming or basking. Despite their size and prehistoric look, they are not dangerous to humans if you keep distance: they almost always flee into water or bush when approached. Problems only arise if a monitor is cornered or grabbed - like any wild animal it can then bite, scratch or whip with its tail. Never feed them; feeding makes large lizards associate people with food and creates conflict. They are scavengers and predators that help control rodents, carrion and pests, so they are a useful part of the island ecosystem. Similar-looking but smaller garden lizards (Calotes species) and many geckos (including the loud tokay gecko, heard at night) also live on the island.

Safety and ethics

Observe from a few metres away; never corner, grab or feed a monitor; keep children and pets at a distance; a startled monitor near water will usually dive and disappear - give it the space to do so.

Frequently asked questions

Are the big lizards on Koh Samui dangerous?

No, not if left alone. Water monitors are shy and flee from people. They can only hurt you if cornered or handled - so simply keep your distance.

Where can I see a monitor lizard on Samui?

Near fresh water: around waterfalls like Na Muang, streams, ponds and mangrove edges, often swimming or basking at midday.

Can I feed a monitor lizard?

No. Feeding wild monitors teaches them to approach people and creates dangerous situations for the next visitors.