Tiny black phoebe rescue/ operation reunite with mama bird was a bust. She wasn't visiting them often enough, and they were likely also too cold at night. We left them alone and watched from a distance, but this evening when we ventured close enough to peek in, one had died and the other two were weak and shivering. So now they're back inside, sharing a heat lamp (in a different bird box) with the chicks. We're doing our best and holding it lightly, as my doula friend would say.