Q&A with David Hillis on Biodiversity in the Texas Hill Country

Author Q&A: David Hillis on Biodiversity in the Texas Hill Country

In his book Armadillos to Ziziphus: A Naturalist in the Texas Hill Country, Dr. David Hillis guides readers through the region’s plants and animals. His approachable essays on the ecology and preservation of the Texas Hill Country cover topics from the summer heat to the beloved animals of the region, including hummingbirds, deer, and even dung beetles. In this Q&A, he talks with us about the beauty and history of the Hill Country and the goals of his book.

Your book goes beyond the traditional nature guide, offering context and practical guidance on a number of topics. What will readers gain from this approach?

Cover Image for Armadillos to Ziziphus: A Naturalist in the Texas Hill Country by David M.Hillis

Each chapter of this book is a stand-alone essay that explores an aspect of the spectacular diversity of the Texas Hill Country. Understanding biodiversity leads to its greater appreciation, so I’ve written the essays to explain the complexity of nature in simple language. I hope the book helps people gain greater understanding and enjoyment of what they see when they visit or live in the area. 

I had several goals in writing this book. One was to discuss the reasons (geology, geography, climate, etc.) why the Texas Hill Country is such a beautiful and diverse place. It is a hot spot of biological diversity, with a fascinating mix of plants and animals from regions to the north, south, east, and west. People are drawn to the beauty of the Hill Country, and its plants and animals are a big part of the attraction. 

Another goal was to discuss aspects of the natural world of the Hill Country that people may see every day (or could see, if they knew to look), but likely have never thought much about. How do trees know when it is time to leaf out or bloom? Why are some grasses green in the winter and die back in the summer, whereas others do just the opposite? Why are flowers such a wide variety of different colors and shapes? 

I also wanted to describe the changes that have occurred to the biodiversity of the Hill Country over time, and what might be causing these changes. Why are many familiar animals—such as Horned Lizards, frogs, and quail—declining? Are there things we can do to reverse these declines? What are some of the practical things that landowners can do to preserve and restore properties to their former glory?

The book also introduces people to aspects of the Hill Country’s biodiversity that they never have seen or heard about, such as the wild and strange animals that live deep in the Edwards Aquifer or the diverse freshwater mussels of Hill Country rivers that have such an unusual way of reproducing. I think most readers will learn a great deal about plants and animals that they already know, while they also learn about fascinating species they never knew existed.

How do Texas Hill Country agricultural industries, including cattle ranching and wine, honey, and olive oil production, impact the biodiversity of the region?

The Hill Country has certainly experienced a lot of development in recent decades. But there are still lots of natural areas left, and much of the region’s agriculture can benefit from the presence of native plants and animals. Most of the Hill Country land is taken up by cattle and hunting ranches, and I discuss some of the ways that preserving native grasslands and other native plant communities has economic benefits to local communities.

What human activities impact the Texas Hill Country the most, and how has this changed in the region’s history?

The biggest concerns for the future of the Hill Country revolve around water use. The Hill Country is fortunate to have an abundant supply of water in its aquifers, springs, rivers, and lakes, but the water resources are finite. In the book, several sections explore the relationship between water and biodiversity, and discuss why conservation, restoration, and protection of water resources is critical to the future of the Hill Country, both for people and for native plants and animals.

Does the relationship between people and the Texas Hill Country need to change? If so, how?

As a landowner and rancher, my goals have been to find ways to live more gently on the land, and to work to protect and restore some of its natural beauty. I don’t claim that the approaches I’ve tried are the only way to do this, but I do discuss some solutions I’ve found that work. Readers who wish to help protect and restore the Hill Country for future generations to enjoy can decide what they would like to accomplish, and then pick and choose from the solutions I discuss.

What is one animal you wish people living in or visiting the Texas Hill Country thought about more often or thought about differently?

It is hard for me to pick just one. But I’ll mention one group that everyone loves: fireflies! I don’t know anyone who doesn’t delight in a field of fireflies as they flash their lights on a summer evening. But this is a sight that is becoming all too rare in the Hill Country. I discuss why fireflies are so much less common than they were in my youth, and the things that we can do to reverse this trend. That is a theme throughout this book—rather than simply lamenting the loss of biodiversity that we have witnessed in recent decades, I talk about how we can turn things around and bring back the populations of plants and animals that make the Hill Country such a beautiful place to live, work, and visit.

How has the Hill Country surprised you as a scientist and as a landowner?

The thing that first caught my attention is the thing that surprises most first-time visitors to the Hill Country: its beautiful, clear springs and rivers. What many may not know is that this abundance of water resources also helps make the Hill Country a global hot spot of biodiversity. We have many plants and animals that are found here and nowhere else in the world. I take readers underground to see the Hill Country’s unique aquatic cave life, on canoe trips down some of its magnificent rivers, and into seasonal spring pools to see what lives there. 

David Hillis is the director of the Biodiversity Center at the University of Texas at Austin’s College of Natural Sciences.