Sunday, July 23, 2017

The Sweet Sound of Confrontation

After writing about Eastern Gray Treefrogs and Cope’s Gray Treefrogs a few weeks ago, I continued to ponder my ongoing inability to actually locate and photograph them – especially when they’re singing. Was I going to have to wait until 2018 to try this again? 

I decided to go for a few evenings of after-dark walks at Orchard Hills Park in northwest Geauga County. Singing insect season would be starting soon, but I was getting impatient. I did a cricket and katydid survey at Orchard Hills some years ago and remembered how many frogs would sing in the wetland restoration area of this former golf course. While waiting for northeast Ohio’s singing insects to reach maturity, perhaps I'd spend more time with the frogs. 

The lush, recently-created wetlands were full of singing frogs, and many were the Gray Treefrogs I’d hoped to study. The walking paths include little bridges and decks that enable accessible wetland viewing. Could this possibly be a location to learn more about these resonant, but cryptic, singers?

I walked past the rowdy commentary of a Green Frog chorus near the water's edge, and they almost drowned out the Gray Treefrogs for a little while. 

You know these frogs. They're the ones that sound somewhat like snapping rubber bands, and they yelp when startled if they're on the bank when you walk past. Look at the sonogram as you listen, and you can see the exclamatory spikes when they call. 

Within minutes, a particularly loud treefrog was close enough that I thought I might actually have a chance to find one this time. My microphone is highly directional and can assist me in locating who I’m hearing, and it definitively stated that I should look in the little willows.   


But would he be on the trunk? In the branches? And what color would he be? Gray Treefrogs can actually change color and have a palette of possibilities between vegetation green and varying shades of gray and brown that resemble a branch …

…like this!

I was delighted! I recorded AND photographed him! The closer I studied his coloration, the more impressed I was with how he blended with his surroundings.

With that immediate encouragement, I was determined to continue looking and listening. Should I check the bulrushes and sedges next for a green individual? 

While searching, I was aware that these frogs were singing on different pitches. The highest pitch of the collection seemed to be the E that the willow resident sang. Other frogs were anywhere from a whole step to a major third lower. 

For example, listen to the lower pitch sung by this frog:

It was the song of a green Gray Treefrog in the marsh vegetation. 


It took considerable time to locate him in the dense texture, but I was again successful! The process of learning more about them was as exciting as actually seeing them.

There were variables in location, color, and pitch. Individual Gray Treefrogs could be either green or brown and could be singing the higher pitch, the lower pitch, or one of the ones in between. Listen:

I was clearly going to have to spend a couple more evenings here.

Before I left that first evening, I heard a very loud voice on the high pitch while walking across a small deck. Although I scanned the rushes carefully for a green individual, I could not find him. I consulted my microphone, which directed me to look straight down…


He was brown like the wood, and I’d been walking back and forth past this little frog while he was singing from the deck!

I came back the next night to determine whether the same frogs were still singing their distinctive pitches in the previous night's locations. They were.  

The brown one in the willows was there. 

The brown one on the deck was there, too, and he seemed to be guarding the edge of it. He sang his same pitch in different directions, but always toward the water. 


Was there a competitor for his territory? I heard a lower pitch coming from the vegetation near the deck,

but didn’t see anything until…


Now that was one imposing individual!

They sang back and forth on their respective pitches. The green one advanced toward the deck, and then climbed onto the edge! 

The brown one did not back down.

The green one advanced even farther. Though seated right on the deck near both of them, I was an irrelevant presence.

The back and forth singing was actually a full-scale confrontation. Just as with American Toads, whose distant songs sound so peaceful and lovely, close proximity revealed the true nature of those sweet pitches.

How would they reach a resolution? Should I stay, or withdraw to avoid interfering? I took some photos and left, as I didn’t want to add further stress to a very tense situation. (I’ll admit that I especially wanted to avoid any additional upset for the brown frog while he defended his space.) 

I came back a third night to see who won the deck space. The frog in the willow was still singing right where I expected. Other treefrogs sang back and forth on their various pitches, and the Green Frogs continued their emphatic discussion.

When I got to the deck, I heard the brown frog’s pitch, and I did not hear the green challenger. How could I distinguish between them? 

I've created a composite track to demonstrate. The first six calls you'll hear will be those of the brown Gray Treefrog. The second six songs are those of the green Gray Treefrog. 

The song I heard when I returned was the first one. What I saw, however, was this:

It was the brown frog, but greener now and moving between the deck and the rushes. His markings were the same, but now his color was green. 

He was still guarding his deck but his position seemed secure, at least for the moment.

I’ll end with a recording of the peaceful, meditative music of Gray Treefrogs singing back and forth, creating a delightful texture of pitches alternating in a repetitive rhythmic pattern that resonates across the pond as if the entire marsh is inhaling and exhaling. 

Funny – it doesn’t sound like territorial proclamations and belligerent threats at all!

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