how old for Gray Tree frogs to call?

[MantidBro]

It took my buddy about a year after i saved him... He was an inch at the time

[Wulf]

I had an eastern male that didn't start chirping until a year old and pretty much full grown. The little cope's male I have now though, he started chirping 2-3 months after I got them. Ordered in a m/f pair last summer since cope's aren't native to my area. (I know, I know.. I prefer to go with CB when possible, and to get tadpoles or froglets as young as possible otherwise. Don't hate me on that please.) The copes had assumed their adult colors, but were less than 1" when I got them, 2-3 months old at most I would guess? He was a little over an inch long when he started trying out his voice. (Love the calls btw) He also has grown into a large specimen, 1.7 inches and not quite a year old yet.
On a note of ways to coax him to sing, mine chirps up a lot right after I mist the tank, certain music sets him off, and beeps from a digital kitchen timer get him puffed right up and singing for some reason. If he is still young, don't stress it, he'll talk to you when he's ready. And once he gets going he probably won't shut up.