Student to Teacher

Mentors, volunteers & lasting lessons of wildlife biology

a box on a stick
The song meter records frog calls. “It’s basically a little green box,” says Saenz. “It doesn’t look fancy, but it’s full of electronics.” Photo by Dan Saenz, USFS.

In Nacogdoches, Texas, a USDA Forest Service office is located on the campus of Stephen F. Austin State University (SFA). When not in the field, it’s where research wildlife biologist Dan Saenz works.

Saenz works closely with SFA professors. As a guest lecturer in 2007, he met Erin Childress, who was an undergraduate student at the time. Childress would go on to work with Saenz for years, finish her undergraduate and graduate work, and become a professor at SFA.

Along the way, Childress listened to a lot of frog calls. Like birds, frogs have many songs. Some of their calls are unpleasant, like the nasal braying of a Woodhouse’s Toad. “It’s fine if it’s just one Woodhouse’s Toad,” says Childress. “But if you get more than five all at the same time, it hurts your ears.”

Listening to frog calls and identifying the species – especially when a whole chorus of frogs of multiple species calls at the same time – is a challenge. “It’s tedious work, and it requires a lot of skill,” says Saenz.

Today, recorders are digital, and the calls they record can easily be shown visually – in waveform or in a sonogram. Saenz loaned one of these recorders, called a song meter, to Childress so two of her students could record frog calls for a project. The students are high school seniors and are part of the SFA Science, Technology, Engineering, and Math Academy.

The song meter is attached to a tree by a private pond. “It’s basically a little green box,” says Saenz. “It doesn’t look fancy, but it’s full of electronics.”

The students program and check on the logger, download the data, and will soon compare their data with another dataset Saenz collected from a similar pond on the Davey Crockett National Forest.

Saenz has been recording frog calls in national forests across Texas for years. “I have so much data,” he says, “That’s what happens when you automate sampling. I’m really glad the students can use some of it.”

students look at song meter attached to tree
Childress’ students are recording frog calls and will analyze the data. Photo by Suzy Jungmann, STEM Coordinator with Lufkin Independent School District.

Saenz and his colleagues have found that, as the climate warms, the timing of frog calls has shifted. And much of our knowledge of Chinese tallow tree and its effects on amphibians is from Saenz and his team – which includes Childress, who contributed to a 2013 study on the interactions between climate change, Chinese tallow tree, and frog survival.

“My work with Dan and others in the office was instrumental in my learning process,” says Childress. “It was extremely beneficial. Project based experiences – setting up a design, collecting and analyzing data – that’s an experience you don’t always get at school. I’ve really tried to provide that experience to my students.”

Before working with Saenz, Childress volunteered with Craig Rudolph, an SRS researcher who recently retired. After she completed her Bachelor’s degree in 2009, she began working on her Master’s degree, and Saenz became her co-advisor.

Over the years, Saenz has worked with many students. Childress is part of a whole cohort of student volunteers – and students who were so skilled and successful that they became paid contract technicians or permanent employees.

Cory Adams and Josh Pierce started as volunteers,” recalls Saenz. “So did James Childress, who’s now a contract biologist [and Erin Childress’ spouse]. Brad Johnson did too; he’s now a professor at West Texas A&M University. Robert Allen was a volunteer, and now he’s a wildlife biologist at U.S. Fish and Wildlife Service. There are many more, I could name maybe 20 people.”

The experiences give students a chance to see what wildlife research is like. Those who enjoy the work and stay often get paid for their time and expertise. “I don’t like people to work for free for too long,” says Saenz. “I like finding a way to pay them because they really help us out.”

tape recorder and a timer
Early technology used to record frog calls. “In 1999, I took a prototype to my colleague and friend who works in the SFA physics department,” says Saenz. “He said, ‘I can do way better than that.’ He designed and built this programmable audio recorder that we used for years.” Photo by Dan Saenz, USFS.

Childress still volunteers with Saenz occasionally. “Out of the kindness of her heart, Erin keeps our weather data up to date,” says Saenz. And she still listens to frog calls sometimes.

But between working with high school students through the SFA STEM Academy, getting ready for a new role as interim director of pre-health, and teaching university students, there isn’t much time. Childress teaches zoology, anatomy and physiology, and several other classes.

“As I’m teaching my classes, especially zoology, evolution is a big chapter that I like to cover right off because it’s so foundational. It’s the overarching link to all sciences,” says Childress, whose Ed.D. thesis discusses student’s perceptions of evolution. “Students can hold religious beliefs and accept evolution. And without strong scientific education, misconceptions flourish and major scientific issues in our society will be ignored.”

Read more about wildlife research at SRS.

For more information, email Dan Saenz at or Erin Childress at

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