Two different species...

Yes Jace..Mork(Green & Golden Bell) will start Inshallah(Southern Bell) croaking. It happens quite often.

They have slightly different sounds. The Southern is a deeper tone with a reverberating/broken sound, Yet the Green & Golden's have a continual pitch.

This morning I heard what I first thought was a Gray treefrog trilling, then quickly realized that since it was approaching fast, high in the air, and didn't sound quite like a frog, it was a Sandhill Crane. As it was flying overhead, a nearby Gray treefrog started calling (I was close enough to watch, no mistake this time). The frog continued to call as long as I could hear the crane.

Today was not a wild-frog calling kind of day-sunny, coolish (~15C) and it hasn't rained in a couple of days. The only frog calling I heard today (and I was outside all day), was when the crane was overhead. I'm 100% convinced the Gray was responding to the crane, so yes, I think frogs will respond to different species. It's also possible I'm losing it.

I just find it fascinating, and rather unexpected. Even the Fire Belly toads get louder when they hear the other two going. Gherkin the African Bullfrog is grumbling more, like he doesn't want to be left out...about the only thing that has remained quiet is the crickets!! And I am definitely not complaining about that!

Brian-that is so neat about the frog responding to the crane. And I hope you're not losing it...we haven't seen enough of your pictures yet!!

I definitely think it is a dominance thing! Now, this is not scientific by any means, but I will say that when Kibbits was just starting to croak, he would only respond to my pretend croak (I'm a woman), and not my fiance's croak (at a much lower interval!)

We also found that he would croak a challenge to "higher pitched" frog callings online, and not lower pitched, more adult whites.

It made me wonder if it was a survival thing. If the croak sounds "younger," they will croak their challenge. It makes sense biologically to me at least. The guy sounds tougher? I'm hiding in the branches. Sounds like I can take him on for the female? Hear me roar!