Introduction: The Concrete Jungle is Teeming with Life
Next time you walk through a city neighborhood, slow down and look around. What may seem like an empty lot of nothing but weeds, or a tiny park tucked between tall buildings, is often a vibrant ecosystem in disguise . It's easy to think that people are the only living things in a city, but a closer look reveals a flash of fur or a flutter of wings—hints of the many kinds of wildlife lurking in even the biggest cities .
Did You Know?
From coyotes and foxes to bees and rare slugs, our urban centers are bustling with non-human residents. This article explores the fascinating world of urban wildlife, the science behind how they survive, and how you can become a detective in your own neighborhood.
The Urban Jungle: Who Lives Here and How?
Not Just Pigeons and Squirrels
While pigeons and squirrels are the classic city survivors, urban areas host a much wider array of creatures . The Urban Wildlife Information Network (UWIN), a global alliance of scientists, works to document this diversity.
They've found that every urban region is different, each with its own unique suite of wildlife, which can include coyotes, foxes, and raptors adapting to city life 3 .
Secrets of City Survival
The city can be a tough place for wildlife. Buildings, roads, and sidewalks leave less space for plants to grow, which in turn affects the animals that rely on them for food and shelter .
So, what does it take to make it in the city?
- Adaptable Diets: The survivors are tough, scrappy, and not picky eaters .
- Innovative Homes: For a pigeon, a highway underpass or a building's eaves makes a perfect place to roost .
- Unexpected Sanctuaries: Sometimes, a pile of junk can serve as a cool, quiet hiding place for animals .
Adaptable Diets
A forest squirrel may live on acorns, but a city squirrel will happily eat acorns, garden plants, tulip bulbs, and even discarded pizza .
Innovative Homes
Raccoons and house sparrows often make their homes inside the walls of buildings .
Unexpected Sanctuaries
A pile of junk can mimic the rotten logs or rock holes animals would use in the wild .
A Key Experiment: The Mowing Frequency Study
To truly understand and foster urban biodiversity, scientists are conducting rigorous experiments. One such study, highlighted by the USDA Forest Service, examined a common practice in urban greenspace management: lawn mowing.
Methodology: Letting Lawns Grow
Researchers set out to determine how the frequency of mowing suburban yards affected local bee populations 6 .
Selection of Yards
Researchers identified a series of suburban residential lawns to be included in the study.
Application of Treatments
The yards were divided into different test groups with varying mowing frequencies.
Data Collection
Researchers regularly visited the yards to count bees and document lawn flowers.
Results and Analysis: More Flowers, More Bees
The results were clear and compelling. The yards that were mowed every two weeks saw a significant increase in both the number of lawn flowers and the number of bees compared to the yards mowed weekly 6 .
Impact of Mowing Frequency on Urban Bee Populations
| Mowing Frequency | Lawn Flower Abundance | Bee Abundance & Diversity | Key Implications |
|---|---|---|---|
| Weekly | Lower | Lower | Traditional lawn care creates anemic habitats for pollinators. |
| Every Two Weeks | Higher | Higher | Reduced mowing supports bee populations, saves time/money, and reduces emissions 6 . |
This study provided concrete evidence that simple, low-cost changes in yard management can have a profound positive impact on urban biodiversity. Mowing less frequently:
- Provides Food Sources: The allowed lawn flowers, such as dandelions and clover, offer crucial nectar and pollen for bees 6 .
- Increases Habitat: Longer grass provides more shelter and nesting resources for insects.
- Saves Time and Reduces Emissions: For residents, mowing less often is a time and cost savings, and it also reduces carbon emissions compared to weekly mowing 6 .
Simple changes can have big impacts on urban biodiversity
The Global Effort to Document Urban Nature
The movement to understand urban wildlife is not confined to research labs; it has become a global community effort. The City Nature Challenge (CNC) is a powerful example of this, a "global bioblitz" where cities compete to make the most nature observations.
A Phenomenal Growth
What began in 2016 as a friendly competition between Los Angeles and San Francisco has exploded into an international event. By its 10th anniversary in 2025, the challenge had generated staggering results from over 669 cities worldwide 8 .
City Nature Challenge 2025 Global Results
3,310,131
Observations
73,765+
Species Documented
102,945
People Participating
3,338
Rare/Endangered Species
Local Discoveries with Global Impact
The CNC has revealed the specific, and often surprising, biodiversity within individual cities. The 2025 results for Los Angeles County, for example, documented 2,803 different species from over 27,000 observations 8 .
Southern Alligator Lizards
A mating pair was an exciting find in a particularly dry year 8 .
San Clemente Island Fox
A subspecies listed as near threatened and endemic to the Channel Islands 8 .
Millipedes
A mass of millipedes observed by a new user, highlighting the hidden diversity in city parks 8 .
These observations are more than just pictures; they contribute to a real-time global database used by scientists to track changes in our planet's biodiversity 8 .
The Scientist's Toolkit: How We Study Urban Wildlife
So, how do researchers and community scientists uncover the lives of these elusive city dwellers? The field relies on a suite of specialized tools.
Essential Tools for Urban Wildlife Research
| Tool | Function | Real-World Application |
|---|---|---|
| Camera Traps | Motion-activated cameras that remotely capture images of wildlife. | The Urban Wildlife Information Network (UWIN) uses standardized camera trap surveys to collect comparable data on animal presence and behavior across cities globally 3 . |
| iNaturalist App | A digital platform and social network for sharing and identifying biodiversity observations. | The foundation of the City Nature Challenge; allows anyone to contribute photos, which are identified by a community of experts and amateurs, and become part of a global scientific database 8 9 . |
| Acoustic Monitors | Devices that record the soundscapes of an environment, from bird songs to bat echolocation. | UWIN is integrating acoustic monitoring with camera trap data to get a more complete picture of urban species, particularly those that are heard rather than seen 3 . |
| UV Flashlights | Ultraviolet lights used to detect organisms that fluoresce under UV light. | Used in workshops like "Not-So-Creepy Crawlers" to find scorpions in the Santa Monica Mountains at night, revealing a hidden layer of invertebrate life 1 . |
Camera Traps in Action
Camera traps have revolutionized urban wildlife research by providing non-invasive ways to monitor animal behavior and population dynamics in cities.
These devices can capture everything from nocturnal coyote movements to rare bird sightings, providing valuable data without disturbing the animals.
Citizen Science with iNaturalist
The iNaturalist app has democratized wildlife observation, allowing anyone with a smartphone to contribute to scientific research.
By simply taking photos of plants and animals, ordinary citizens can help scientists track species distributions, monitor population changes, and even discover new species in urban areas.
Conclusion: Coexisting in the Wild City
The evidence is clear: our cities are not biological deserts. They are dynamic, functioning ecosystems that provide a home for a remarkable array of species. The goal of urban wilding is not to let cities go completely feral, but to redesign our urban infrastructures to account for our non-human neighbours, moving beyond mere co-existence to a relationship that is mutually supportive 2 .
Taking Action
This involves everything from the simple act of mowing our lawns less often to participating in global community science projects.
- Reduce pesticide use in your garden
- Plant native species that support local wildlife
- Create habitats like birdhouses and insect hotels
- Participate in local biodiversity monitoring programs
A New Perspective
The future of urban wildlife depends on a radical transformation in how we view and plan our cities. It requires us to give citizenship and personhood to non-humans and to embrace the psychological and ecological benefits of a wilder city 2 .
You can be a part of this transformation. It starts by stepping outside, looking a little closer, and documenting what you find. The wild city is waiting for you.
To learn more about the Urban Wildlife Information Network, visit their website. To participate in the next City Nature Challenge, download the iNaturalist app and look for events in your city every April.