How long can a baby bird last without food or water?

never EVER give a bird water until it is ready to fly. giving it water you can actually drown it. if its eyes are not open you need to feed it ever 15-30 minutes. if you have time you should go to your local pet store and get wild bird food. I use whats called Nutristart it is blue and has a weird looking bird on the front. if you dont have time then you should get some dog food and put warm water in it untill it is some what watery. you need to keep it in a noise free enviorenment or it could die from stress. empty out a water bottle and put hot water in it. wrap a paper towell around it and put it next to the bird. this will keep it warm and calm. birds mothers are their warmth so when it feels the warmth it will calm down thinking it is with its mother. if you have a heating pad you should put the container on the heating pad. hope this helped