Help me sex these frogs!

[ejh805]

I need help sexing my Milk frogs. I can get better pictures if needed, but these are all I have for now. Tried to get clear pictures of their "thumbs". These are three frogs

[ejh805]

I came home from work last night to witness the largest singing his little heart out. So I believe they're a trio of males since the other two are a bit smaller.

[ejh805]

Spoke briefly with Eric Ivins, the breeder, yesterday and he said that the females call too. So now I'm even more confused! Still looking for insight if anyone can offer it.

[Mentat]

Hello Emily ! Myself do not keep them; but have read the adult males (around 1.5 years old) are smaller, call, and develop nuptial pads (noticeable all year but more marked after breeding conditioning): Care and breeding of Amazon Milky Frogs Phrynohyas resinifictrix.

[ejh805]

Thanks Carlos!!
I've only had these for about 8 months and they were teeny tiny babies when they arrived, so nuptials wouldn't yet be visible I assume. Maybe the one calling (not a whole lot bigger than the other 2, but a lot fatter) is a female?

[Mentat]

Does it call like this?

[ejh805]

No sir, the croaks sound similar but the sides don't expand like that. It's more in the throat area under the mouth and doesn't stretch the skin much at all.