Michael, you have a point with the stress level. I was not the first owner of any of my WC grey tree frogs, by the time they came to me, they were already acclimated to captivity with exception of Atlas, who was barely alive and just a baby when I got him. My kids did catch some common green frogs from the pond behind our house and wanted to keep them. We had them for about a week and we still couldn't move or speak in the room they were in without them rushing for cover. We released them because of it.
If your new grey doesn't adjust well, it's about the time of year that you can start watching for newly morphed froglets or even tadpoles.