A remarkable refuge for a vast ecosystem
02.11.26
By Steph Dodson
If you ask someone who has been to Bracken Cave Preserve why it is special, they won’t give you just one answer. Maybe it’s the breathtaking bat flights, the warmth of the staff and volunteers, or the rare feeling of being deeply connected to the land—but for most, it’s all of these at once. In 1992, the preserve was established with a 4.7-acre plot of land surrounding the world’s largest known bat colony.
Today, there are nearly 3,500 protected contiguous acres surrounding Bracken Cave, co-managed by Bat Conservation International (BCI) and The Nature Conservancy. The land around the cave is shielded from development that could bring light and noise pollution, factors known to disrupt bat behavior and potentially threaten the stability of the colony. The Mexican free-tailed bats (Tadarida brasiliensis) of Bracken Cave have now become a superstar umbrella species. Safeguarding this maternal colony creates a ripple effect, offering refuge to many other species.
From Batnado to Biodiversity Bloom
Bracken Cave Preserve also serves as a field research hotspot, attracting researchers studying not only bats but also birds, plants, and general ecology. The success of protecting the cave highlights how protecting one charismatic and ecologically pivotal species can have lasting benefits for an entire ecosystem.
What visitors see on the surface is only possible because of the work happening every day behind the scenes. BCI’s staff at Bracken, Director Fran Hutchins and Project Coordinator Krystie Miner, oversee a wide array of conservation activities throughout the year. A non-exhaustive list includes BioBlitz projects, guano DNA sampling, emergence data collection, Endangered golden-cheeked warbler surveys, cowbird trapping, legacy tree surveys, white-tailed deer population surveys, and cavity/roost searches.
Many of these efforts rely heavily on the dedication of Bracken’s 200+ member volunteer community. Some of Bracken’s longest-serving volunteers have been returning for nearly 20 years—a testament to the magic, awe, and wonder inspired by the preserve and its inhabitants. That same enchantment draws new volunteers each season, eager to be part of something extraordinary. Each year, bat flight tours attract thousands of visitors to witness one of nature’s most breathtaking spectacles, the legendary Batnado—the emergence of millions of Mexican free-tailed bats, as they spiral out of the cave at dusk for their nightly insect hunt.
A Living Classroom
Bracken isn’t just a preserve; it’s also a hub for scientific discovery. There are many students, at all levels of academia, who use Bracken for their studies. PhD candidate Kristin Dyer from the University of Oklahoma is studying the climatic drivers of Mexican free-tailed bat migration and the interactions between migratory timing, parasitism, and bat health. PhD candidate Amanda Waugh from Texas A&M University is studying the bioaccumulation of pesticides in bat blood and guano, exploring the broader implications for ecosystem health. Master’s student Megan Spina from Texas A&M University – Kingsville used the preserve as one of many sites as she studies the effects of urbanization on White-winged Dove (Zenaida asiatica) movement and breeding ecology in Texas.
The love for Bracken and its legacy as a research site even spans generations. Dr. Troy Murphy of Trinity University studies the ratio of males to females, and the interplay between social dynamics in the Black-crested Titmouse (Baeolophus atricristatus), examining the adaptive and biological drivers behind these patterns. His daughter, Caitlin Murphy, a high school senior, designed a project to measure predator abundance, primarily snakes, at varying distances from the bat cave as a prey source.
A Wealth of Species
My connection to Bracken deepened even further when I began my own research here. My practicum course, a component of earning my Associate’s of Applied Science in Conservation & Wildlife Management through Austin Community College, allowed me to partner with BCI in the Fall of 2025. Under the guidance of Fran Hutchins and Krystie Miner, part of my undergraduate research has centered on species richness: the diversity of species present across the preserve. Studies like this often serve as a first step in ecological research; after all, without understanding what species inhabit an area, we can’t accurately assess how human activity is impacting the environment.
Bracken isn’t just a preserve; it’s also a hub for scientific discovery.
As a starting point, I carried forward a project that first started in March 2025, when Dr. Sarah Fritts, a professor at Texas State University, brought her wildlife techniques class to the preserve to install six Adapted-Hunt Drift Fences (AHDriFT). The project launched with 12 camera traps across 6 distinct locations. Each AHDriFT setup included a five-gallon bucket at either end, with a traditional camera trap aimed downward to view inside—an approach designed to detect reptiles and small mammals that often go unnoticed by standard trail cameras. There were a total of 1,793 sampling days from March to the end of October, during which the AHDriFT cameras captured a total of 128,533 images. After collecting and analyzing the data, I found 3,172 images that contained wildlife, and the resulting species breakdown was ecologically fascinating.
The Sound of Texas Stars
As Craig Hensley, the biologist who first taught me about acoustic monitoring, often said, “the only way to 100 percent know which bat species is present in an area is to have it in your hands.” This means if you rely on acoustic monitoring software, you can be no more than 99 percent confident that a species is present, and even then, a keen eye for detail on the manual vetting of the echolocation calls is needed to confirm what the software is suggesting. These details can then be used as a starting point for deeper research into the other chiropterans using the preserve.
My love for Bracken Cave Preserve is deep, but it is not unique. As a volunteer, I’ve witnessed the joy, awe, and wonder on people’s faces time and time again, as they experience one of the greatest natural phenomena on Earth. As a researcher, I’ve held these bats in my hands and learned more from them than I ever expected. It’s hard to convey just how special this place is, and if you haven’t visited before, the season runs from May until September each year (something to dream about during the chilly winter months). The funds from tickets, memberships, and donations do more than safeguard millions of bats in Texas and across the globe; they also protect the many other species that rely on the preserve as a refuge from the relentless loss of wildlife habitat. Now, more than ever, protecting the land these animals call home is not just important; it is essential.
Bracken Cave Preserve serves as a field research hotspot, attracting researchers to study not only bats, but also birds, plants, and general ecology.
Learn more about visiting Bracken Cave Preserve
If you’re interested in doing research at Bracken Cave Preserve, contact Krystie Miner at [email protected]
Steph Dodson is a conservationist, field researcher, and lover of all wildlife. She earned her Associate’s of Applied Science in Conservation & Wildlife Management from Austin Community College in 2025 and is now pursuing her Bachelor’s of Applied Science with a focus in Conservation & Wildlife Biology from Texas State University. Find her on Instagram @wildlife.conservation.steph
