Found a fledgeling and it won't eat? Help

[FrostyWind]

Good Day,
Found a fledgeling, no parents around and could hardly fly. I've been watching it on the ground for almost a Day. I put it in a tree away from dogs and cats and no one came.
Brought it inside and try to feed it but he won't open his mouth, he's still sorta healthy but his eyes are starting to close often now. Certain he's getting weaker but the guy just won't open his mouth to feed. Even when I'm force feeding him he just somehow manages to throw it back up. It's a Kiskadee and was giving him different types of insects wherever I could find them?
What to do?

 

[RiverOtter]

Found fledglings are often dehydrated. Try giving it a bit of water.

Tap at the flanges at the base of it's beak with an eyedropper and see if it opens it's mouth.

Kiskadees are omnivores and are apparently known for liking bananas. So perhaps mash some banana and make a slurry with some water and see if it will take that a drop at a time, then work up to flies when it's swallowing.