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That’s the curse of radio reporters. If you hear something mysterious, unexpected, or new, you want to get that sound. It doesn’t matter what time of day. It doesn’t matter what else you do. You want to film it. What if you never hear from him again? What if it is important? You have to get it.

I’ve had this compulsion with a specific sound in my neighborhood for years. I hear it mostly, but not exclusively, in the spring and early summer. And it is not, strictly speaking, a sound.

Instead, it’s a collection of sounds that seem to come from the same source. It’s a high-pitched, peeping, whistling, chirping kind of thing. It comes from trees, rocks, walls and yards. At times it even seems to come from the ground. And it always seems to be the same animal making the noise.

It confused me because it sounded like it could be a lot of different things, and going through the dozens of recordings I made didn’t narrow it down.

I thought they were birds chirping in their nest. It can sound almost exactly like that, except there’s a flickering, screeching component that comes in to ruin the impression.

This screeching sound is reminiscent of crickets or katydids and for a while I thought it must be a bug.

But the noises seem scattered and irregular. They do not follow the rhythm of insects. They also sometimes sound almost like a whistle, which I’ve never heard a cricket do.

I even briefly entertained the idea that geckos were the cause. I had heard that geckos could make sounds and the sounds started in the spring about when I started noticing them in my yard.

But some theories point to a less organic origin. A neighbor of mine even thought the squealing was coming from burst or over-pressurizing water pipes.

I have seen many things in my yard: bugs, birds, snakes, lizards, frogs, raccoons, and water pipes.

I’ve never seen a frog.

They turned out to be frogs.

People hear frogs all the time, but they never see them

There’s a place on the UT Austin campus that Tom DeWitt calls “the frog room.” It is aptly named as it contains shelves of terrariums, each home to a different species of frog.

Devitt is a professor and researcher at UT Austin who specializes in amphibians. After emailing some experts about our neighborhood mystery, I contacted him and he invited me into the frog room to uncover the likely source.

“A lot of people have never seen one, but you hear them all the time,” he said as he took down a terrarium that appeared to be filled mostly with a piece of limestone.

From inside this stone Devitt brought out a small frog. It was no more than an inch and a half long, brown in color with brown spots. He looked very shy.

“This species is called the chirping rock frog,” he said. “They are a native species.”

Devitt calls them mysterious. Small, good at hiding, hard to find.

He said that’s the challenge of studying them: They’re really hard to observe in the wild. There are also different species of chirping frogs around Austin.

The rock-chirping frogs prefer rocky outcrops on the west side of town: hence the limestone. But DeWitt suspects that what I heard in my yard might be the chirping of Rio Grande frogs.

They are closely related species that are more likely to make their home among trees and vegetation. They are also more recent arrivals to Austin, possibly coming from South Texas as potted plants.

“There was a big nursery in Brownsville, which is kind of where they’re from,” he said. “We think they probably came from there, but we can’t be sure.”

Rio Grande chirping frogs have spread across much of Texas and Louisiana. Until now, they appear to have occupied a slightly different ecological niche than rock frogs and offered little competition.

Frogs are everywhere, but we don’t know much about them

Chirping frogs aren’t like most frogs you’ve heard of.

For one thing, they don’t need a lot of water. There is no tadpole stage for these frogs. They simply lay eggs and the young hatch directly from them as baby frogs. So they can live in yards, like mine, without regular irrigation.

Since they lay eggs, they also behave differently. Whereas most frogs simply fertilize their eggs in water and leave them to their own devices. The chirping frogs hover around and take care of them.

In fact, male frogs may actually be their primary caregivers.

“They will sit on the eggs. Move them around,” Devitt said. “I think they’re usually just keeping them from predators is the idea.”

They somehow survive the droughts and heat waves of Texas – probably by slowing down their metabolism. But how exactly it works, and how they know when to do it, is not entirely clear.

In fact, the more we talked, the more it became apparent that there was a lot we didn’t know about these frogs. Although they are everywhere.

“I think it’s fascinating that we have biodiversity around us that we know almost nothing about,” Devitt said.

But he wants to know.

How exactly do they reproduce without water? How far do they travel in their lifetime? How long do they live?

“We have no idea,” he said.

In fact, it’s not even entirely clear why they make these strange sounds.

“They’re having two kinds of conversations,” Devitt said. “One is kind of like a slight shaking noise. The other is a kind of whistling or chirping of insects.

A sound is probably used to attract mates. The other to guard territory. But again, Devitt has to study them to find out.

“I want to know everything about these frogs and what it’s like to be one,” he says. “That’s what I’m all about.”

To do this, you need to find them.

So a few weeks later. KUT photographer Michael Minasi and I joined Devitt at the Brackenridge Field Lab off Lake Austin Boulevard on a frog hunt.

Michael Minasi

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CORNER News

Come on a frog hunt

The trail Devitt chose is perfectly suited for rock frog hunting. It runs past what used to be a quarry where stone blasting has exposed a limestone rock face, providing ideal habitat.

Walking the trail at night my microphone picks up bugs, birds, wildlife rustling in the bushes. But one thing we didn’t hear much was the chirping of frogs.

“As it’s gotten later in the season, they’ve been coming out less and less,” he warned.

Fortunately, he didn’t need to hear them to catch them.

One by one, Devitt spotted the frogs like shiny pennies on the rock in our flashlight beams.

We found four that night, despite their reluctance to chirp. Some were very small, maybe half an inch long.

“It makes me wonder if these are the ones that hatched this year,” he said.

The little ones he left behind. But he took one male to take to the lab.

He hoped to see if the frogs would mate in captivity to learn more about how they reproduce and raise young.

But when I called to check a few weeks later, he said he had no luck and released them back into the wild.

He thinks he may have waited too long into the year and collected frogs that were no longer interested in mating.

One reason for this theory? These super tiny frogs we found. If they were newly hatched, did they signal the end of the frogs’ mating season?

“I don’t want to speculate too much,” he said. “But…it’s not that often you see the little ones and we saw a few of them pretty quickly.”

So instead of answers, we end this story with another question about the mysterious chirping frogs of Central Texas.

Did we help welcome into the world this year’s new generation of chirping rock birds, freshly hatched from some hidden clutch of eggs?

For now, we have no way of knowing. But Devitt plans to look for answers next year, when that strange screeching, whistling and chirping sound once again fills the air.