There are several ways you can help if you find a nest or bird house on the ground.
If the babies are unharmed, and respond with a peep when gently touched, a new nest can be fashioned out of a small container (with the lid off). Poke holes in the bottom of the container for drainage. Use wire or duct tape, and attach it to the tree as close to the original spot as possible. Place the old nest in the container with the babies.
If the nest is completely destroyed, pack the container tightly with grass clippings making a bowl shape in the centre. Watch to see if the parents return. If you are making a substitute nest for a baby that can’t be placed back in the nest with its siblings, the nest should be observed for a longer period of time. Studies have shown that often, parents will feed the single baby only for a few days before abandoning the nest. Sometimes this is enough though if the young are close to fledging.
If a birdhouse has fallen or been damaged, they can often just be put back up and the parents will return. In some cases though, only a hasty repair can be done and the birdhouse should be removed and repaired as soon as the young have fledged.
If a tree has been cut down with a nest in it, the limb can be removed and attached to another tree as close as possible to the original location. If this is not possible, the nest should be put up as high as possible in some nearby cover like a hanging basket. In one instance we have put a wooden box of young crows on the roof of a garage after the only tree in the area had been cut down and the parents continued to raise them.
If the nest has been down for some time and the babies are cold and unresponsive, they will have to be warmed up. Do this by placing the nest or container on top of a heating pad set on low, or hot water bottle. A pop bottle filled with hot water can also be used. Replace the nest in the tree as soon as they become more responsive. If the parents do not return within the next hour they should be brought to a rehabilitator. Call the hotline at 306.242.7177. Keep your distance while watching so you don’t frighten the parents away.