Fallen fledgling wood pigeon

 Hi, every year wood pigeons come back to a tree in our garden to nest. Last night a baby seems to have fallen out of the nest. I am guessing it is 15-20 days old (some feathers some fluff and quite big) my dog spotted it and although excited wouldn’t hurt it so I can keep her away and she keeps the cats away! It has nestled quite nicely under the edge of some stored wood so I feel it’s in a safe sheltered spot but I don’t want it to die. Will its mother feed it on the ground? The nest is directly above about 12ft up. Can I put any food down maybe defrosted peas? Haven’t seen mum visit it yet but I haven’t been watch that long. Please advise! Thank you