I went and looked out that window. I now have 6 of them around and in that bamboo. I hope they do stay there. They'll be warmer and closer to their food. They seem okay, just cold and have their feathers fluffed and nestled down in the ivy, pine straw and bamboo leaves.
I guess they are okay, it's just different behavior than I've noticed before.
I thought mourning doves were always ground feeders... The ones around here are on the ground all the time, and I have to rescue them from our cats!