Saturday, July 8, 2017

Mistaken Identity

 Photo by Lisa Rainsong

In the past couple of years, many more people have begun recording nature sounds with their phones and capturing sounds in videos with their cameras. Not only are they listening more closely and communicating about what they hear, they’re also sending recordings along with their questions to me.

A frequent inquiry in later May and in June this year was either, “What bird is singing at night near my house?” or “Are these crickets? Isn’t it too early for crickets?”

When I listened to the recordings they’ve sent, my answer was,”it’s neither one. These are frogs – Gray Treefrogs.”

Here’s our well-known Gray Treefrog, the Eastern (or Common) Gray Treefrog (Hyla versicolor).

Now listen closely to a single individual and look at his sonogram. 

The species name, “versicolor”, refers to their variable color. They can be green or varying shades of gray and brown, changing to blend with where they’re currently located. A young, bright green frog blends well when sitting in meadow vegetation… 

 Photo by Lisa Rainsong

 … and gray individuals blend so perfectly with tree branches and green lichen accents that the frogs are practically indistinguishable from their surroundings.  

 Photo by Jerry Cannon

Listen to this rich chorus of frogs in Twinsburg near the Summit/Portage County border (north of Akron)! Can you hear a few Spring Peepers in the mix as well?

Now here’s another chorus from a different location.  Who’s singing in this one?

Green frogs? You all know that one. When I do amphibian song programs, I always tell people it’s OK to laugh. You know you want to.

 Photo by Lisa Rainsong. Can you see the spider on the frog?

And Bullfrogs? Oh, yes – the basso profundo of the frog chorus.

 Photo by Lisa Rainsong

But what about the others? Gray Treefrogs…but am I being specific enough? 

 Photo by Jerry Cannon

I didn’t make this recording anywhere near Cleveland. So what exactly seems a little different from the recordings at the beginning of this post? If you’re from southern Ohio, though, you might think this ensemble sounds quite familiar.

The Eastern Gray Treefrog’s look-alike cousin - Cope's Gray Treefrog (Hyla chrysoscelis) -  resides in the southern third of the state.  The last recording you heard was made at Buzzard’s Roost Nature Preserve in the Chillicothe area of the Ross County Park District in southern Ohio.

We can’t tell the species apart by the physical appearance. It  would be easy to mistake one for the other. Range is a big clue, though range itself isn’t enough to determine identity because the two species can overlap. But that sound! Their songs (or technically, “advertisement calls”) will reveal their true identity. 

 Photo by Jerry Cannon

Did you happen to notice the short, yelping calls in the recording? When I first heard these, I wasn’t sure it was one of the frogs – especially since I don’t know Cope’s Gray Treefrogs well at all. Could it have been some kind of marsh bird? Here’s a detailed excerpt and sonogram.  


I had an additional idea about what I was hearing and seeing, and I knew that park district director Joe Letsche could clear up any potential mistaken identity for me. One of the males was indignant because another male was getting in his personal space and perhaps even mistakenly grabbing him. If the latter were the case, this would be a “release call.” No eggs here, buddy! Just move along.

 Photo by Jerry Cannon

Do I have a preference between the two species? Well, yes. I think our Eastern Gray Treefrogs have a prettier “song.” But especially after my most recent visit to Ross County, I’ve become quite a fan of the Cope’s Gray Treefrogs as well. They’re a bit more strident, but so delightfully raucous and entertaining! Here's another chorus recording from Ross County with even more individuals singing. You've already identified all the singers, so you'll be pleased that you can tell what you're hearing.

If you'd like to hear a short recording of both species actually singing together, you can find one here. Look for "Cope’s and Eastern Gray Treefrog." If the MP3 doesn’t work for you, the WAV file likely will.) Here's an Eastern Gray Treefrog sonogram above and a Cope's Gray Treefrog sonogram below. The Cope's song is a little longer and higher in pitch, and you can see the greater density of the sound.

 And don't forget - they look identical!

 Photo by Jerry Cannon

I’ll close with a recording that begins with Eastern Gray Treefrogs immediately followed by the Cope’s Gray Treefrogs.  When they're not singing siumltaneously, can you hear the difference now? Regardless which song you prefer, they are both quite splendid!

(Several of the photos in this post are by citizen scientist and photographer Jerry Cannon. He has dedicated more volunteer hours to Summit Metro Parks than anyone else, including working for years on both daytime and nighttime surveys. I only have a few Gray Treefrog photos of my own, and his photos made it possible for me to complete this post. Thank you, Jerry!)

 Photo by Lisa Rainsong


  1. Wonderful! Thank you for sharing this great information! 😍

  2. Lisa, thank you for putting recordings of these sounds we commonly hear side by side, makes it a lot easier to ID in the field