Birds:
Nestlings are small birds with few feathers and no tails that usually have fallen out of their nests. They do not have true feathers or tails. Try to locate the nest they came from, it is usually very near where they were found as at this age they are not very mobile. Place the baby back in the nest if safe to do so. THE SCENT OF HUMANS WILL NOT DISCOURAGE MOTHER BIRDS FROM TAKING CARE OF THEIR YOUNG! Birds have a generally poor sense of smell.
If placing the baby bird back in the nest is not a safe option, make a make shift nest out of and old basket or margarine container, or a plastic container with no lid. Punch holes in the bottom for drainage of rain water, and attach to a nearby tree branch far enough above ground for the baby to be protected from cats and dogs. Line the bottom with paper towel. If the parents have not returned by evening, there is a problem, please call a rehabilitator for help. Birds can not take their young as they can not carry them, they can only fly down and feed them where they are so please make sure the "nest" is accessible.
Fledglings: These are small young birds with tufted feathers and small tails. They are fully feathered. They are often found on the ground hopping around flapping their wings and making a scene as they attempt to learn how to fly. THEY ARE NOT ORPHANS!
Young birds learn to fly by jumping out of the nest, usually a few days before being totally ready. They spend this time on the ground under bushes and flowers while the parents keep a close eye on them from a distance, coming in to feed them and teach them how to fend for themselves. Do not pick them up to help them. They are fine and being normal young birds. If in danger from cars etc. please gently shoo them under a nearby bush. If in danger from cats or roaming dogs, please keep the domestic animals indoors or on leashes. Cats will hunt whether hungry or not. Next to humans, domestic animals do the most harm to wildlife, endangering not only the wildlife, but themselves and their owners as well due to the possibility of contracting diseases and other communicable agents such as parasitic worms.
Please do not give food or water to baby animals as they can drown, aspirate and get pneumonia, or choke. Call a rehabber or vet for advice.