Owlets should only be removed from the wild when they are in danger of dying if left. It is recommended by The Owl Foundation that you give the owlet you encounter a second chance to remain in the wild. If you happen upon an owlet on the ground who appears to have fallen from a nest and whose parents do not appear to be around exam the owlet for injury by gently but firmly feeling the owlet's body, legs and stretching out the wings. You are looking for swelling from fracture or dislocation. An owlet that has become injured will be abandoned by its parents once they discover the injury. If the owlet is injured it should be removed from the wild; however if there is no evidence of injury the owlet should be placed either on a tree branch or if able back in the nest from which it fell. Any individual attempting to replace an owlet in its nest must be aware that if the parents are watching or return they will not take kindly to the intrusion. The owlet should then be left for several hours, after which time it should be checked on again, if the thin owlet remains where you left it or back on the ground human intervention may be required to ensure its survival.
Any person removing an owlet from the wild should contact an owl rehabilitation center. In the even that the owlet can not be turned over to the facility immediately the baby owl will require basic care place him in a warm, dark confined place a box placed inside your home will work fine. When at all possible do not feed or interact with the owlet as this can leave an imprint on the owlet and render him unable to be returned to the wild. However, if you must keep the owlet for a few days he will also need to eat, while chopped rodents would be the owlets dinner of choice cut pieces of stewing beef rolled in powdered eggshell will suffice.
To locate an owl rehabilitation center near you check The Owl Pages at www.owlpages.com