1: You could try to find an Avian Vet nearby, See if they will take it. They might help
2: See if there are any bird rescue places neaby
3: look up on the internet about the kind of bird you have
4: if you can see if you can get baby bird formula for small birds.(sold at pet stores) You will need a syringe (sold at local pet stores) Learn how to feed a small bird. I was taught by a bird breeder. If you do manage to do this then make sure you feed them from one side of their mouth or the other. NEVER STRIAGHT IN!!!!!! You may have to force them Idk...]
Last: if you have not touched it yet, Try to put on laxtex gloves on and gently place the baby back into the nest when the mother is gone. Watch to see what happens.
I wanna know what you choose to do and how it turns out, (Is that strange?) so post additonal details after, If you could? No biggy if you dont..... I just really like birds...
Hand raised a Cockateil. Formula feeding and all