I rescued a baby blue jay from my cats?

what do i do with it? how do i feed it and it wants to fly but cant and i dont know what to do. if i put it outside the cats will get it but if i put it up high it wants to jump out and fall. it has slept plenty and the only thing the cats did was swat him around and kinda hurt his head. but he seems fine now. i have called the wild life ppl and they said they were closing to bring it in tomorrow but he is all antsy and whatnot. so i dont know what to do with him and they said to keep in in a box with a soft cdloth so i just tried it and he keeps cherpping ang hoping around in it so i have to close the lid. if you cud give me any advise that would be great!