A Concert of Western Music

It’s March – and that means the early amphibian songs are filling wetlands, ponds, and vernal pools throughout NE Ohio. It’s always exiting to hear the explosion of song that proclaims the beginning of spring as frogs pour into the communal pools they will share for their brief annual period of reproduction. 

This year, many more people seem to be making brief videos to record the sounds they’re hearing. I love sharing their delight in the sounds of the natural world! I’m also receiving  inquiries about which species of frogs are singing. With the video clips they’ve made, I can answer their questions. 

There’s one identification question I’ve gotten from a number of people, and I think I can help clear up some amphibian song confusion right here in Listening in Nature.

It's the Western Chorus Frog, who makes one of my very favorite amphibian songs. 

Those of us who live in Cleveland and the Northeast Ohio snow belt counties hear a LOT of very loud Spring Peepers every year, so that's a song most of us know. Some people may feel they’ve experienced permanent hearing loss after spending a couple hour by a pond, vernal pool, or marshy area that’s filled with these boisterous little frogs. 

 

Some of us also know the Wood Frogs singing in vernal pools. Their songs are often compared to quacking ducks – very different from the treble voices of the Spring Peepers. Here's a whole crowd of them in a NE Ohio vernal pool.

Western Chorus Frogs, however, are more common a little west and southwest of my area, so I have to travel a bit to hear them. It is well worth it! 

Tiny and very well concealed, they're probably going to be in some wet vegetation with only their heads above the water. 

Their vocal sacs look like large bubbles and are likely to be easier to spot than the rest of the frog. You’ll be delighted if you can actually see one inflating his vocal sac and singing...

...but he’ll probably freeze into silence when he sees you, and then allow his vocal sac to collapse before slipping discreetly below the surface.

Most of the recordings I’m using for this post are from Killbuck Marsh Wildlife Area southeast of Wooster. You may even be able to hear the water spilling from the marshy area at Messner and Valley Roads into the creek.

Let’s listen to a single Western Chorus Frog and look at a sonogram of his song. It’s often described as sounding like someone running their fingers along a comb. 

The top portion of this sonogram illustrates how the song gets louder. Doesn't it look like a crescendo? The bottom portion indicates how the pitch ascends; this corresponds to the shorter teeth of the comb. You can also see that the songs and the spaces between them are generally quite  consistent.
 

The song doesn’t have clear pitches like those of the Spring Peepers, but sounds rather like a percussion instrument that's played with a scraper (perhaps a guiro). Because the pattern repeats relatively unchanged at very regular intervals, it soon sounds quite predictable. The song is consistent in length, speed (tempo), and volume (dynamic level). It's louder overall than one might expect, but still not quite as loud as the Peepers.

Here’s an isolated comparison of a Western Chorus Frog and some typical Spring Peeper songs.

When you can recognize the Western Chorus Frog song, let’s try mixing in a Spring Peeper or two. Can they be heard singing at the same time in the same location? Absolutely!

Peepers peep, but on occasion, they can make a song that ascends instead of staying on one simple "peep" pitch. Here’s a collection of Spring Peepers; listen to the variety of songs. The Western Chorus Frog is in the mix, too. Can you still hear him?

Sometimes Peepers will make an ascending trill (very rapid notes) that could remind you of the Western Chorus Frog song. 

 
The Peeper, however, will always have clearer pitches. Listen for the Peeper's trilling song combined with the Western Chorus Frog as you look at the sonogram excerpt below. The Western Chorus Frog's song has a wider span and looks more like the teeth of a comb. The Spring Peeper's trill covers a smaller span, but it is bright and dense. At the end of this sonogram picture, their two songs briefly overlap. They don't have to take turns, and they have no interest in making song identification any easier for you.

We’ve been listening to a single Western Chorus Frog, but the next recording will feature a chorus of them with a Wood Frog soloist. I don’t think you’ll confuse the Wood Frog with the other early spring frogs; the pitch is lower and really does sound like quacking rather than peeping or trilling. The Western Chorus Frogs create a dense texture of sound between 3000 and 4000 Hz.

Think you’ve got it now? Listen for them in sunnier, more open marshy areas a little west and south of Cleveland. Toward Columbus and in western Ohio, they should be bountiful. 

I’d also tell you to look for them, but you’ll just get frustrated. They are as tiny as Spring Peepers and are nearly impossible to find unless they’re in a small, shallow area and continue to sing when you’re close to them. Good luck with that – I know some of you are going to try!

My final recording of the series is the entire ensemble: Western Chorus Frogs, Spring Peepers, the ever-present Canada Geese, and a scattering of other birds singing or calling. Go listen for them soon - it's a short concert season!