How do you care for a baby bird that fell from it's nest?

It had feathers and can hop pretty well and attempts to fly but, is still to young. I found the nest put it back and the mother pushed it out after about 3 hours. There's another baby around the same age in the nest still though. And there's one but a cat attacked the nest, we think that's why it fell out originally, and killed the third baby. So there's two the one that the mother pushed out and the one that's still in the nest. I've called local wildlife shelter before for 3 abandon baby birds, they sadi they can't help them unless their owls, falcons or eagles.