Reptiles in the city: Should we welcome our reptilian overlords?

Think about a classic urban species. The first ones that come to mind are usually rats, pigeons and cockroaches. I’d bet that less than 10% of people reading this thought of a reptile. With cockroaches (and possibly ants) being the exception, most big names of the city are birds and mammals. Rats, mice, squirrels, (feral) cats and dogs are all classic examples of mammals one might find in many cities. Pigeons, seagulls, crows and magpies are generally common urban representatives of the birds. Reptiles and amphibians are often overlooked when discussing urban wildlife. However, these creatures can also be considered urban classics! Lizards, frogs, and toads are found in many cities worldwide, though they are usually found in warmer climates compared to more familiar urban residents like rats and pigeons. Despite this, they are an integral part of the city ecosystem and can be beneficial to their human neighbors. While amphibians are just as fascinating and crucial as their reptilian cousins, this blog post will focus solely on reptiles. Amphibians deserve their own dedicated discussion, which could be explored in a future post.

A personal experience with urban reptiles I had was in Bangkok. My family and I were in the city for only a few days, as we were more interested in exploring the natural parts of Thailand. One of the first things we noticed were the enormous rats—some larger than rabbits—which were a significant problem for Bangkok citizens. Later, during a boat tour, we saw the banks of the rivers and canals teeming with enormous monitor lizards. Our guide told us that these lizards lived in gardens and on rooftops, basking in the sun. The locals weren’t scared of them; in fact, they welcomed these huge reptiles, some over two meters long, because the monitors helped control the rat population, keeping the food web in balance and preventing a so-called ‘giant rat plague’.

A more globally common example of urban reptile is the gecko (often Hemidactylus spp.). These small lizards are found in homes worldwide and are often considered a staple in many households. Although often labeled as the ‘friendly house gecko’, they can be any gecko species. They are found in cities with warm climates across the globe and are generally considered to be a beneficial guest by locals. This is because they eat mosquitoes, sometimes consuming up to a hundred a day, and are known to hang around light sources that attract potentially harmful mosquitoes such as Aedes aegypti (yellow fever mosquito). Being mostly nocturnal, geckos are a welcome presence in many bars, preying on insects drawn to the evening lights and thus reducing the insect nuisance for human guests.

Geckos are often regarded as docile (not looking at you, tokay gecko) and even cute household guests. They provide a beneficial service to humans by preying on mosquitoes. The monitor lizards in Bangkok also inhabit urban environments where they play a crucial role in controlling rat populations and, although potentially dangerous, are generally beneficial. The American Alligator (Alligator mississippiensis) is another formidable reptile, bigger than the monitor lizards and exhibiting a higher potential danger. However, its role in the urban ecosystem remains somewhat unknown. Frequently found in urban waterways and even on golf courses, it occasionally ventures into urban areas, evoking both fascination and concern among residents. They are not generally deemed as beneficial to an urban ecosystem but do prey on mammals which can be a nuisance (e.g., raccoons and rats). They are now considered true locals on Floridian golf courses, being recognized as integral inhabitants and are often named, thus adding to a cultural significance in urban areas.

Unlike most species named so far, snakes are almost always unwanted. They are often still seen as dangerous evil creatures (thank the Bible for that one) which couldn’t be further from the truth. In some cities, venomous and potentially dangerous snakes could be present, but usually more generalist species are more common. Returning to Bangkok, the generalist reticulated pythons actually serve the same role as the mentioned monitor lizards, preying on the rat population and keeping it in control. Yet, these snakes are usually removed when found and are not as welcomed as the lizards. They can grow to enormous lengths, giving rise to myths of them eating adult humans, which rarely happens and has never occurred in any city. However, they are just as effective at removing pests as monitor lizards and provide many benefits to the city. The misunderstanding of these animals could lead to an increase in pest populations, highlighting the importance of their presence in urban ecosystems. Despite their often negative reputation, snakes like reticulated pythons could play a vital role in controlling pests and maintaining ecological balance in cities.

In conclusion, while reptiles are often overlooked in discussions about urban wildlife, their presence and contributions are crucial. They provide many services, such as geckos eating pesky mosquitoes and monitors and pythons preying on pest animals like rats. In the case of Floridian alligators, they can even hold cultural significance. Integrating reptiles into our cities can enhance biodiversity, improve pest control, and create more balanced ecosystems. To truly integrate nature into our urban environments, it is essential to consider reptiles in our planning and conservation efforts. By doing so, we can foster healthier and more sustainable cities for both humans and wildlife.

 

Sources

A global assessment of research on urban ecology of reptiles: Patterns, gaps and future directions—Brum—2023—Animal Conservation—Wiley Online Library. (n.d.). Retrieved June 14, 2024, from https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/acv.12799

BBC Two—Cities: Nature’s New Wild—Snakes in the city. (n.d.). Retrieved June 14, 2024, from https://www.bbc.co.uk/programmes/articles/7fm2hSywLF648l4LJVxrBl/snakes-in-the-city

Golf course living leads to a diet shift for American alligators—Rosenblatt—2023—Ecology and Evolution—Wiley Online Library. (n.d.). Retrieved June 14, 2024, from https://onlinelibrary.wiley.com/doi/10.1002/ece3.10495

Thailand’s capital has a python problem: Snakes are invading homes | World News—Hindustan Times. (n.d.). Retrieved June 14, 2024, from https://www.hindustantimes.com/world-news/bangkok-snake-problem-bangkok-snake-complaints-thailand-s-capital-has-a-serious-problem-1-snake-encounter-every-15-minutes-101664774042516.html

The gecko: An environmentally friendly biological agent for mosquito control—PubMed. (n.d.). Retrieved June 14, 2024, from https://pubmed.ncbi.nlm.nih.gov/9430109/