Cool Lizards in the City: How Irrigation is Changing Urban Wildlife

Have you ever noticed a lizard basking on a sidewalk or darting across a college campus? It turns out, these urban reptiles might be living a very different life than their wild cousins! Our Cool Lizards in the City project—a collaboration with 11 universities in Southern California—is investigating a fascinating question:

👉 Do animals living near humans benefit from irrigation systems that provide a constant water source?

An urban lizard "chilling" in a crack in a wall.

Lizards & Sprinklers: A Surprising Connection

In cities, irrigation keeps parks, lawns, and gardens green, even in the middle of scorching summers. But could this steady water supply also be shaping the lives of western fence lizards (Sceloporus occidentalis)? We think so! These little guys thrive in urban areas, and we suspect that access to extra water might be keeping them:

✅ Cooler in the heat

✅ More hydrated 

✅ Active for longer periods throughout the day

How We’re Testing This

To find out, we’re placing environmental data loggers across urban college campuses and natural non-urban sites. These devices record temperature, humidity, and soil moisture, helping us compare how microclimates differ between urban and wild areas.

A data logger collecting temperature and soil moisture readings at an off-campus natural site.

We’re also tracking lizard body temperature, hydration levels, and activity patterns to see if urban lizards really do have an advantage thanks to all that extra water.

More Than Just Lizards: Training Future Ecologists!

What’s even cooler? This project isn’t just about lizards—it’s also about training the next generation of ecological leaders! At each participating university, a faculty member is working with an undergraduate researcher who is directly contributing to this project.

We’re partially funded by RESCUE-Net (https://rescue-net.org/), a research collaboration network that supports student training in ecological research. Together, we’re giving students hands-on experience in fieldwork, data collection, and ecological analysis—preparing them for future careers in science and conservation.

Why Does This Matter?

Urbanization is changing landscapes worldwide, and while some animals struggle to adapt, others—like fence lizards—may actually be thriving. Understanding how urban environments impact wildlife helps us better protect biodiversity in a rapidly urbanizing world.

So next time you spot a lizard chilling on a campus walkway, remember—they might just be living the high life, thanks to human-made watering systems! 💦🦎

Stay tuned for our results—these cool city lizards have a lot to teach us! 😎

Elmer proposes his thesis!

BREE Lab Master's student (now candidate!), Elmer Gutierrez, successfully proposed his thesis at the end of spring semester. He is looking at how predation risk is modified in burned habitats and whether lizards exhibit enhanced reliance on color-matching in these areas where most of the above-ground vegetation has been burned. He has worked so hard on this project and I can't wait to see what we find!

BREE Lab Represents at SCAS!

BREE Lab graduate students got a chance to present their research at the annual Southern California Academy of Sciences Meeting (https://scas.nhm.org/annual-meeting) at Chapman University over the weekend. Daisy presented her preliminary results on how urbanization affects (or not!) lizard limb and toe morphology and locomotor performance, while Emily presented her final results (yay!) on how native lizards bask less in the presence of an invasive competitor. Congrats on great oral presentations!

In addition, Taylor, who is a mentee in the Natural History Museum's UNLAB program (https://nhm.org/unlab), co-mentored by Dr. Putman, presented a poster on her research examining rodenticide exposure in Southern California snakes! About a third of the snakes we processed tested positive for rodenticides.

It was a great time for the students and trainees to gain more public speaking experience and to catch up with old colleagues and meet new friends.