First determine if the bird is a nestling or a fledgling. A nestling is a very young bird that has just hatched and has little to no feathers. If it’s a nestling, your best option is to return the bird to the nest if you see it. It is okay to the bird, the mom will continue to feed it.. If you are unable to reach the nest, you can create a make-shift nest such as a plastic bowl with a couple of holes at the bottom of the bowl or basket and nail it as high up you can reach up the tree; the mom will feed it from there.
If the bird is a fledgling, it will appear fluffy, with some feathers and a few naked patches. These birds are meant to be on the ground and in low branches. They spend about a week learning to fly and the parents will feed them and try to keep them hidden in a bush or up against your house. Watch the bird to make sure it does not appear lethargic. These birds do very well on the ground, and it is the only way they will learn to survive on their own. Cats, dogs, and kids always seem like major threats to these small, young birds, but resist the urge to pick it up and bring it into us unless it is injured or unable to stand.