Baby Bird Drama!!!!!?

I found a baby bird on the ground, my friend suggested we leave there in case the parents came for it. So I sat near by and watched, the mother never came and the bird had started to breath heavily under the hot sun. I took it home fed it some formula and strips of cloth for it to nest on. I found out that it's a baby Raven, most likely, and I called shelters, but all say they won't have enough time to put in the bird to have it live{ aka. they prob just put it to sleep}. Any-Whoo....Is there anything else I can do for this bird???