Often they are frightened into this error by a hawk or some other surprise. A feeder placed within three feet of a window may prevent birds from building up deadly speed before the collision. Paper cut-outs spaced about the window pane may help to show birds that it is a surface. Birds stunned after hitting windows often revive. Leave it alone and keep pets away.
Most young birds leave the nest well before they are able to fly.
Their parents, who may be rarely seen, will return as needed to feed them. Not only is picking up the bird a violation, it disrupts the bird's opportunity to learn survival skills. On the rare occasions that a featherless young is found on the ground, an effort should be made to replace it in its nest. If a nest has fallen, fasten it in a tree near to where it was found. If the bird simply suffered a concussion and there are no broken bones, there's a chance for survival.