Injured baby bird - help!?

I've come across a baby bird (a fledgling I'm guessing as it's not pink and rather has its feathers) - it must have fallen out of a tree, because my dog got to it. Fortunately she's a gentle labrador and had no intention of killing it, but didn't understand that carrying it around in her mouth was damaging.

I got it off her. It was breathing and seemed to be in shock, but I couldn't tell what the injuries were like. I returned it to the tree, but the nest was way too high, so I placed it lower down and was hoping the mother bird would work out the rest.

An hour has passed and the bird is in the same spot and all the birds from that tree seem to have gone quiet.

What should I do? (It's the evening here so there's not much I can do in terms of taking it anywhere). Do I leave it in the tree and keep my fingers crossed (hoping it doesn't fall out again or a cat doesnt come along), or should I try and retrieve it again and get it warmed up? If the latter, then what?

Thanks for any advice.