

Advice needed to rescue a baby mourning dove
i dont know if this is the correct place for these kinds of questions, apologies if not, but there was a mourning dove that made a nest on the balcony of my fourth floor apartment, i live in a medium sized city, we don't use the balcony much so other than putting out a bit of seed and water for her, we mostly just left her alone to roost. i noticed she was sitting on eggs a week or two ago and didn't really think much of it, but yesterday i went out to the balcony and found one dead baby and another one just sitting on the ground with insects all over it but it was still clearly alive. i didn't see the mother anywhere and when i checked the nest it looked like it had been torn apart. i didn't want to interfere, but the nest was ruined and i didn't think it was safe to try and put it back up there and i couldn't leave it on the ground either, so i got a box and lined it with paper strips and a towel and set the baby in it on a table very near where the nest was. i kept checking for the next couple of hours to see if the mother returned, but she never did.
i didn't really know what to do and the baby was clearly not doing well so i brought it inside and cleaned it up and looked up what food i could give it in an emergency and several sites said cat/dog food mashed up and warmed could be a substitute in a pinch so that's what i gave him and he seems to be doing better now. there aren't any wildlife rescues near me but i am planning on taking it to one a couple hours away once the weekend comes. until then though i bought some baby bird formula and a syringe and i'm going to start trying to feed it with that.
my real question is, is there anything else i need to know or do in order to give this little guy the best chance at surviving until i can get him to the wildlife rescue? i've been feeding him every 2-3 hours and i've been checking his crop before and after feeding. he's been sleeping A LOT but seems comfortable. right now he's in a small cardboard box with a heating pad underneath half of the box and i keep a blanket over half the top of the box unless i'm feeding him.
how often should he be eating? how much should he be eating based on his current growth? should i or shouldn't i feed him at night? if anyone has any info or general advice i'd greatly appreciate it!