Lumpini Park is famous for its population of free-roaming monitor lizards, specifically the Asian water monitor (Varanus salvator). As the world's second-largest lizard species, hundreds of these semi-aquatic reptiles live freely around the park's lakes, basking on the lawns, climbing trees, and acting as ecological scavengers.
Varanus salvatorWhile their large size can be intimidating, the monitor lizards in Lumpini Park are accustomed to humans and rarely behave aggressively unless provoked. As cold-blooded reptiles, they spend the early mornings lying on canal banks or asphalt paths to regulate their body temperature. These skilled swimmers use their long, flattened tails as rudders and can stay underwater for up to 30 minutes. They are also adept climbers, often scaling tall trees to seek food or escape threats.
As carnivores and active scavengers, these monitor lizards help maintain Lumpini Park's health. Their diet includes catfish, pigeons, turtles, and animal carcasses. By consuming organic waste and dead fish, the Asian water monitors prevent water contamination and naturally control rodent populations, occupying the top of the park's urban food chain.
Semi-aquatic behaviorWith an abundant food supply and no natural predators in the park, the monitor lizard population can grow rapidly. In 2016, the Bangkok Metropolitan Administration (BMA) relocated around 200 lizards to a wildlife breeding center in Ratchaburi following complaints of path damage and minor bicycle collisions. Today, park rangers actively monitor the population, which is estimated at 200–400 lizards.
Tua Ngoen Tua ThongThe monitor lizard has a dual reputation in Thai culture. Its formal Thai name, 'hia' (เหี้ย), is traditionally associated with bad luck and used as a strong swear word. To combat this stigma, locals refer to them as 'tua ngoen tua thong' (silver and gold creatures). Despite the cultural superstition, the Asian water monitor is officially protected under Thailand's Wild Animal Conservation and Protection Act B.E. 2562 (2019), making it illegal to harm or kill them.
How to safely observe the lizards
Water monitors are wild animals. They are not aggressive toward humans under normal circumstances, but they will defend themselves if they feel threatened. Follow these simple rules to ensure a safe visit.
Stay at least 2 to 3 meters away from the lizards. Do not try to touch, pet, or pose closely with them.
Feeding the lizards is strictly banned. Human food is bad for their health, and regular feeding makes them lose their fear of humans, leading to begging behavior.
Always leave an open escape route, especially toward the water. If startled, a lizard will run directly toward the lake and may knock down anything in its path.
Lizards often cross the running and cycling tracks or lie on the asphalt to warm up. Cyclists and runners should remain alert, particularly around bends.
While bites are rare, monitor lizards have sharp teeth and bacteria in their saliva. If bitten, wash the wound with soap and water immediately and seek prompt medical attention.
Answers to common questions about Lumpini Park's monitor lizards.
No. The lizards in Lumpini Park are Asian water monitors. Komodo dragons are a different species native to Indonesia. They are larger, hunt large mammals, and have venom. There are no Komodo dragons in Thailand.
They produce only a mild venom, not dangerous to humans, but their mouths harbor bacteria that can cause severe infections if a bite occurs. They generally run away from humans. They will only attack with their tail, claws, or teeth if they are provoked, cornered, or handled.
Do not try to push or scare it. Give it space and walk around it. The lizard will eventually return to the water on its own.
Yes. In Thailand, the Asian water monitor is a protected species under the Wild Animal Conservation and Protection Act B.E. 2562 (2019). It is illegal to harm, capture, or kill them, and violators face fines or imprisonment.
The population is estimated at 200–400 lizards. The city government periodically counts them and relocates some to wildlife breeding centers in Ratchaburi if the population grows too large for the park's resources.
