I agree, this is almost certainly a mature male. He will live less than a year, maybe even a few more weeks or months.If you found it wandering around in the open, it is likely a mature male looking for a mate. They don't last very long to begin with, so it's best just to let him go about his business. Personally I am against taking them out of the wild regardless, so even if it wasn't a mature male, I'd still just release it.
Me either. I had to go back and lookLol, I didn't even notice the banana!