Help! Calling All Birders!

Earlier this evening, I opened the back door to let Luna in and something weird happened. She didn't bound over to me. In fact, she stood at the edge of the patio smiling at me, but not approaching. I called her. She nudged something on the ground. The something on the ground moved. I called Luna more firmly. She came in. I went out.

Luna had a bird. I think it is a young mourning dove, but I'm not 100% confident. Can anybody confirm that for me? The poor thing lost a lot of feathers (including its' tail feathers), but seems to be generally okay otherwise. I don't believe it can fly now. We have it in a big box with mixed seed from the bird feeder and some water. My goal is to keep it alive until it can fly again. Advice?!?