Bangkok's Giant Monitor Lizards Find a Home in Parks, Canals and City Life

Hundreds of Giant Lizards Share Bangkok's Green Heart

Several hundred Asian water monitors are thought to live in and around Bangkok's Lumphini Park, sharing one of the capital's largest inner city green spaces with runners, picnickers and visitors. Nearly two metres long when fully grown, these reptiles belong to the world's second largest lizard species, surpassed only by the Komodo dragon.

As of January 24, 2026, their presence tells a story that stretches beyond a park attraction. Thousands live across Bangkok's canal network, finding food, shelter and routes through a city where buildings and expressways have replaced much of an older landscape of wetlands and waterways.

Before dawn, the canals and large ponds around Lumphini Park can be almost still. As the sun rises, scaly snouts emerge from the water, followed by long, muscular bodies moving onto muddy banks. An early morning walk offers a chance to watch the animals bask beside people going about their daily routines, without a ticket, guide or enclosed wildlife display.

Bangkok, described as the world's most visited city, offers travellers an unusual encounter with a species whose history stretches back millions of years. The lizards are not a traditional tourist attraction, yet their presence gives visitors a glimpse of the city's ecological past.

Lumphini Park is the most accessible place to see them, but their habitat extends into residential backstreets and busy commercial districts. Once pushed towards the city's edges, the reptiles have adapted to the metropolis. Their growing visibility has brought admiration, amusement and practical problems, changing how residents and authorities respond to animals long associated with bad luck.

Why the City Provides So Much Food

Michael Cota, a retired associate at Thailand's National Science Museum who has studied Asian water monitors extensively, explained their success from his study in northern Thailand. He pointed to both the size of Bangkok's population and the animals' willingness to eat almost anything.

Their population in Bangkok is much, much greater than you'd ever see in the wild. When it comes to food, they'll eat anything they can get a hold of, dead or alive. They're extreme generalists.

A generalist is an animal that can use many kinds of food rather than depending on a narrow diet. Bangkok's monitors eat fish, birds, smaller animals, carrion and discarded food waste. Carrion means the remains of dead animals. This flexibility lets them use resources that other species might leave untouched.

Food in the wild can be scarce or unpredictable. Bangkok supplies a steady stream of scraps and other material to eat, helping the lizards survive amid dense development. Their feeding also provides useful services: they help control rat populations and remove organic waste.

Natural predators are another part of the explanation. In their natural habitats, young monitors can be eaten by crocodiles and large birds of prey. Those major predators are absent from the heart of Bangkok, giving the lizards fewer natural threats and a high chance of survival.

Bangkok's tropical climate and abundant water complete a favourable setting. Together, food, water and the lack of natural predators allow the population to grow and adults to reach impressive sizes. The same conditions that support the reptiles also bring them close to people, because food and waterways run through places where residents live, work and exercise.

Canals Connect More Than Parks

Almost 1,700 canals, known locally as khlongs, thread through Bangkok's neighbourhoods. For water monitors, they function as a transport network, connecting places to feed and shelter without requiring the animals to cross busy roads.

A recent study using citizen science records from the Global Biodiversity Information Facility examined Asian water monitor sightings across major Southeast Asian cities. Citizen science data includes observations recorded by members of the public. Researchers used those records to investigate where the animals occur within urban areas.

Parks and gardens were the main places the lizards occupied across the cities examined. Singapore and Jakarta had sightings heavily concentrated in designated parks. Bangkok stood out because a substantial percentage of observations occurred outside those green areas.

The study suggested that Bangkok's canals, and even its sewage systems, help explain that pattern. Water channels connect separate patches of suitable habitat and allow monitors to travel from the outskirts into the dense city centre. A park can therefore be one stop within a much larger living space.

Urban development often harms reptiles by removing habitat and creating pollution. Asian water monitors have become an exception, making use of structures built by people. The study described them as the largest lizard with established urban populations, while noting that they have received relatively little attention from ecologists.

The research also suggested that their arrival in different cities probably involved independent instances of adaptation. In simple terms, monitors in separate places appear to have found their own ways to live in urban surroundings, rather than all being part of one expansion into cities.

How an Unwelcome Animal Became a Lucky Visitor

Thai attitudes towards water monitors have long been shaped by fear and dislike. Their common name, hia, became one of the language's most offensive insults. The animal's reputation was therefore carried in an everyday word as well as in beliefs about bad luck.

That stigma likely began when families lived in open shelters beside waterways. Scavenging monitors would search for food and sometimes locate the bodies of people who had died before their families discovered them. This association helped create a lasting aversion to the reptiles.

Ice Russameesritrakul, a restaurant owner in Bangkok's Chinatown, described a change in how some younger residents view the animals. Her account connects an older belief in misfortune with a newer association with luck.

In old times, people said they were unlucky. But right now, their symbolism is changing. Some younger people think they're cute and lucky. I know lots of people who will drop everything to buy a lottery ticket if a big water monitor accidentally finds its way inside their home.

A lizard entering a house can still cause alarm and require removal. For some residents, however, the same unexpected visit now provides a reason to buy a lottery ticket. Different reactions exist side by side as the animals become more visible.

From a Convenience Store to Tourist Photographs

TikTok and Instagram have helped turn Bangkok's monitors into familiar characters. Videos show them moving through shopping centres, interrupting runners and swimming in park canals. Scenes that once might have prompted only fear now also draw amusement and affection.

A video from 2021 showing a monitor climbing a convenience store shelf became a widely shared example of that shift. The response was largely amused and affectionate, helping make an animal with an unwelcome reputation a social media attraction.

Tourists now visit Lumphini Park hoping to photograph the reptiles or take a selfie with Bangkok's "Godzillas". The attraction is rooted in the unusual sight of very large wild lizards living beside the ordinary routines of a major city.

Park authorities have installed a giant water monitor statue in the centre of Lumphini Park. The statue signals official acceptance of the reptiles as part of the city's ecosystem and reflects their growing appeal to visitors. Their popularity, however, exists alongside the work needed to manage encounters in homes, businesses and public spaces.

Firefighters Handle Reptile Calls Too

Golden Mount Fire Station, a few kilometres from Lumphini Park, frequently receives calls about monitors that have wandered into homes or businesses. Its emergency work includes dealing with wildlife as well as responding to fires.

S Ruengdach, a firefighter with 30 years of experience, described the frequency of animal calls and the effect of wetter weather on monitor activity.

On average, we get more calls about rescuing water monitor lizards and removing snakes than fires here. They like the rain, so they venture out more in public during wetter weather,

Monitors are generally harmless to people, but a large reptile appearing indoors can be startling. The animals have also raided livestock and moved into popular fishing spots, bringing their search for food into conflict with residents' activities.

Rain makes these encounters more likely because the reptiles venture into public more often during wetter conditions. Their ability to move through water and use a wide range of food sources helps them survive, while also taking them beyond places where people expect to see wildlife.

Keeping Space Between People and Lizards

Lumphini Park's runners face a more immediate practical problem: a monitor crossing a path can become a tripping hazard. Sharing the park requires attention to animals moving between the water, banks and other parts of the grounds.

Residents describe large adults as slow and relatively easy to avoid. Smaller juveniles move faster and can be more aggressive, making them harder to dodge. Size alone therefore does not explain how an encounter may unfold.

Authorities advise people to keep a healthy distance, never feed the animals and avoid approaching them on land, where they may feel threatened. Visitors drawn by photographs still need to leave the reptiles enough space.

Those precautions fit the way the monitors live: they are free to move through the park and the wider canal network. A close encounter is part of sharing that space with wild animals, whether someone regards them as lucky, frightening or simply interesting.

Why the 2016 Removal Had Only Temporary Results

In 2016, authorities launched a large operation to remove monitors from Lumphini Park because of concerns about overcrowding. The effort reduced numbers only temporarily, and the population rebounded.

A female water monitor can lay a clutch of about 20 eggs at a time. That reproductive capacity helped numbers recover after the removal operation. The reptiles are now more visible than ever, and the management approach has shifted from removal towards accommodation.

The main developments trace a change in both official action and public attitudes:

• In 2016, authorities carried out a large removal operation in Lumphini Park over overcrowding concerns.
• In 2021, a video of a monitor climbing a convenience store shelf became a social media touchstone.
• By January 24, 2026, monitors had become a tourist draw, park authorities had installed a giant monitor statue, and restricted commercial breeding permits had recently been issued.

The population's recovery helps explain why removing animals from one park offers only a temporary response. Bangkok continues to provide the food, waterways and favourable conditions that have supported their success across the city.

Commercial Breeding Joins the Management Debate

The Thai government has recently issued permits allowing restricted breeding of water monitors for commercial purposes, including leather goods. The move adds a commercial element to a management approach that also recognises the animals' tourism value.

Officials believe permitted breeding could benefit communities that face conflicts with monitors while reducing illegal hunting. The policy connects the reptiles' economic value with efforts to manage their relationship with people.

Bangkok's experience brings several roles together in one animal. Monitors attract visitors, remove organic waste and eat rats, yet they also enter buildings, disturb fishing spots and sometimes raid livestock. Their usefulness and their nuisance value are both part of daily coexistence.

The city's canals remain central to that relationship. They preserve routes through a landscape transformed by development, allowing these descendants of an ancient species to live in a modern metropolis. Bangkok's giant reptiles are a living link to its wetland past, supported by the conditions of its concrete present.

The Essentials

• Asian water monitors are the world's second largest lizard species after the Komodo dragon and can approach two metres in length.
• Several hundred are thought to live in and around Lumphini Park, with thousands across Bangkok's canal network.
• Almost 1,700 canals help the reptiles move through residential and commercial neighbourhoods.
• A broad diet, abundant water and the absence of major natural predators support their urban population.
• Research found a substantial share of Bangkok sightings outside green spaces, unlike the strong park concentrations in Singapore and Jakarta.
• Public attitudes have shifted from associations with bad luck towards affection, tourism and, for some residents, good fortune.
• A removal operation in 2016 had temporary results; females can lay about 20 eggs in a clutch.
• Authorities have recently allowed restricted commercial breeding, including for leather goods.
• Visitors should keep their distance, never feed monitors and avoid approaching them on land.