Can a baby pigeon survive by herself?

  So, i found a baby pigeon near my house, under a tree, when i looked up, i saw the nest, so i put it back, then i came back to check on him after a hour or two, and it was down on the ground again ..

Judging on the fact that it can fly, a little bit, it's maybe about 30-40 days old.

I have seen it's parent around the nest, but they don't seem to see it on the ground ... so my question is, can it survive now by itself? Or will it's parents see it? Can it already find food? And , if needed, how can i feed a bird? Please, help.
if it's a fledgling (meaning its a baby bird learning to fly), it will be fine.As long as you still seem the parents coming back to nest , there is nothing to worry about. you can still keep an eye on the nest, just don't go peeking in there every 5 minutes. It can survive by itself, but it'll probably stick around by nest a little longer, then fly away to live life as a bird. Don't feed it, and don't interact with it (unless it is an emergency), but you can watch it. You don't want the bird getting accustomed to humans.
NO !!!!!!!!!!!!!!!!!!!!!! Key word is BABY. Do not let it survive on it's own