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The Brackenridge Field Laboratory

George Washington Brackenridge had big plans for the 500-acres of Colorado Riverfront property he purchased.  It was downriver from the future site of the Austin Dam; the Austin Dam which would be built with stone quarried from his property and that was expected to generate the power needed to jumpstart industrial development in Austin.  Brackenridge planned to sell sites along the river to the cotton mills that were sure to come. But the Colorado River never provided the steady power needed to light the growing city of Austin, much less drive mills. Then in 1900 the dam spectacularly broke and attempts to rebuild it failed twice.  So Brackenridge, a regent at the University of Texas, donated the tract to the University in 1910 with the hope of moving the campus there where it would become known as “The University on the Lake.” Again his hopes were dashed when his longtime rival, George Littlefield, donated a million dollars to the University with the stipulation that the campus never be moved.

Amazingly, Brackenridge’s tract of now extremely-valuable riverfront property is still owned by UT. Most of the land was used for housing but in 1966, a biological field station was established on 82 acres of the land.  It was named the Brackenridge Field Lab (BFL). Fast forward to the present: for fifty years, data has been continuously collected on the BFL’s four main habitats: the Upper Terrace, the Old Quarry, the Pasture and the River Terrace.  There have been 1200 species of Lepidoptera, over 160 species of birds, 370 species of plants and 200 species of native bees documented on the BFL.  More than 500 students take courses every year at BFL and do research in its 18,000 square-foot laboratory. Research conducted at BFL has led to successful biocontrol measures against invasive fire ants (RIFA) with phorid flies and against Arundo donax with wasps. 

CAMN has entered into a partnership with BLF to provide assistance with field research, resource management and public outreach.  CAMN members conduct flora and fauna surveys to document arrivals, departures and behaviors related to seasonal changes. Decades of urban landscaping resulted in significant encroachment of invasive species which CAMN members are helping to mitigate.  CAMN members also plan to develop guided hikes curriculum to introduce the public to the wonders of this hidden urban ecological gem.  
 BFL is a unique site in Texas to study and observe how habitats, plants and animals respond to environmental changes and urban disturbance.  If you would like to be a part of this unique opportunity, check out the volunteer opportunities in the volunteer section. 

The Bracken Bat Brigade

Before my first CAMN field trip, it hadn’t rained for weeks. The ground and grass had long gone dry and crackly. I didn’t even think to check the forecast before leaving the house.

But Texas weather always punishes the complacent and unprepared.

My carpool group arrived early at Bracken Cave. We wanted extra time to chat with fellow CAMNers and eat the dinner and snacks we’d brought. Instead, as soon as we pulled up, it began to pour with raindrops so heavy they sounded like hail on the roof of the car. We waited, and I started to worry we’d miss the bats or the rain would prevent their emergence.

Just as I was pulling up the weather radar on my phone, the rain stopped. We got out of our cars and were met by a volunteer from the Lindheimer Chapter of TxMN. He gave us a quick overview of the bats living in Bracken Cave.

The facts surrounding Bracken Cave are near unbelievable.

Holding up to 20 million bats in the summer months, Bracken Cave contains the world’s highest concentration of mammals. As our guide pointed out, Tokyo and Delhi can’t compare. 500 baby bats can fit in just 1 square foot of ceiling space in the cave. 

So many mammals in one spot creates quite the stink too. Ammonia from the guano wafted up towards our viewing point above. Our guide informed us that over 70 feet of bat droppings filled the bottom of the cave. 

I knew I was about to see A LOT of bats, but knowing is one thing, experiencing the sheer numbers up close and in person is something else. The group grew quiet as the first bats started flickering around the entrance. They swiftly grew into a large, swirling cloud that our guide called a “bat-nado.” The sound of their wings was similar to the sound of a soft, pattering rain.

Dark ribbons of bats formed. They rippled in a drifting stream, which rose above the trees and stretched out towards the horizon. 

It began to rain again, and the bats stopped emerging. However, our guide said this brief (30 minute) interruption had been happening each night even without the rain. We took the intermission to hike to an old guano mine shaft and learn more about the land’s history and Bat Conservation International’s stewardship. 

Eventually we returned to the cave to watch more bats emerge and were told that they would continue to stream out until almost midnight. Our group stayed until lightning lit up distant thunderclouds, and it got too dark to see the bats – although we could still hear their fluttering wings.

Trips to Bracken Cave are limited. One of the best ways to get out there is through an organized CAMN field trip. To find out more about visiting go to Bat Conservation International’s FAQ page.

Meet the Webmasters of CAMN

Every week the members of CAMN volunteer their time in support of the great conservation and education work being done throughout the parks and natural areas of Travis County. The coordination of these efforts is no small feat! There is a team of CAMNers working behind the scenes every week to make sure that all your digital resource and website needs are available and up to date.

When prospective naturalists go through the application process for CAMN, the tech team creates and manages the online application and provides support for applicants. Throughout the training year, the tech team works with the class coordinators to provide an online resource for class schedules and training information.
More recently, the tech team has made a big effort to provide more content for CAMN members on the website through regular blog posts and an up-to-date calendar featuring volunteer and advanced training opportunities.

Of course, there are also a slew of small tech tasks that CAMN needs for day to day management: email aliases, website hosting, all that fun stuff. But don’t be fooled by their technical prowess, the tech team – Dan Galewsky and Leslie Lilly – still prefers to spend most days out in the woods.

To reach them and say “hello” email

Join us at the next Communication Team meeting to learn how you can help with CAMN’s website, social media, and the Reader:

Saturday, September 7th | 3:00pm – 4:30pm @ Cherrywood Coffeehouse

To get involved in other ways behind the scenes with CAMN attend the next Chapter Board meeting (open to all members): 

Thursday, September 12th | 6:30pm – 8:00pm @ the Austin Nature & Science Center

A day of weather, climate and water birds at Hornsby Bend

The 2016 Trainees completed their second class recently. It was held at Hornsby Bend’s Center for Environmental Research, a department of Austin Water Utility. Dr. Kevin Anderson (director of the CER) lectured on the history of ecology in the U.S. and Texas. Jon W. Zeitler (Science and Operations Officer, National Weather Service, Austin-San Antonio) spoke on the complex topic of what defines weather and climate, while Dr. Ruth Buskirk (University of Texas at Austin) introduced the trainees to taxonomy.

After lunch, Dr. Anderson gave the group a tour of the biosolids composting facilities, and led a hike through a small part of the 1,200 acres of riparian forest habitat at Hornsby. The walk highlights the bird blind built to facilitate watching the spectacular diversity of migrating waterfowl. At another stop, he discusses the progression some of the land made from being accidentally-bulldozed for a parking lot to becoming the mid successional forest that is present today.

Native Plant Sale

LBJWCLBJWC Public Spring Native Plant Sale will be April 11-12, with the Members-Only Sale on April 10. You’ll be able to choose from nearly 300 species of hardy Texas natives bred to thrive with our Central Texas climate.

Admission: $10 adults, $8 seniors and students, $4 children 5 through 17, and members and children under 5 are free.

  • Please bring your own wagon to haul your purchases.
  • We have free cold filtered water, but bring your reusable water bottle or buy one in the store
  • We will not be recycling plastic pots at this plant sale, please
    consider recycling them at your local recycling center

Full details:

Mike Quinn

Happy Trails

Lace cactus in Bauerle Ranch
Lace cactus in Bauerle Ranch

Got a chance to hike with CAMN member Michelle P. yesterday, one last time before she leaves Austin on her big adventure north. We hiked a few of the trails over in Bauerle Ranch, stopping to admire a ridge of lace cacti and watch a grey fox cross our paths, as well as the many things starting to bud or bloom.

We’ll miss Michelle. CAMN will be just a little less bright without her unwavering presence at our training classes and events, not to mention her cheerful willingness to help with any task that needs doing.

Best of luck, Michelle, and may the trail rise up to greet you (and may it loop back to Austin every now and again!)

December Monthly Meeting


Join us December 3 at 6:30 pm to hear Wizzie Brown (Urban IPM), Entomologist with Texas A&M AgriLife Extension Service speak on ants, both native and invasive. She may include information on Austin’s newest invader, the Tawny Crazy Ant… the one that makes people wish they had their imported fire ants back.

Event is free and the public is welcome, as well as friends, spouses, random people off the street. For CAMN members, this is our last meeting of the year, and your last CAMN-organized chance for Advanced Training.

Located at the Austin Nature & Science Center. Parking is under the Mopac bridge on Stratford Dr.

Light refreshments served.