Goldfinches generally nest in May or June on the West Coast and lay eggs soon after the nest is built. Eggs hatch after 12 to 14 days, and the babies generally leave the nest 11 to 15 days later. In the time between hatching and leaving, the nestlings are vulnerable and must be fed by their parents. If you have found baby goldfinches that you know have been abandoned and aren't able to care for themselves, spend a couple of weeks feeding them, then release them into the wild.
Set up a substitute nest for the baby. Put wadded tissues in a bowl or berry basket to provide warmth, comfort and security for the baby goldfinch. Make sure the tissues are tight enough around the baby to support its body. Turn on a heating pad or lamp and set it near your nest to keep the baby goldfinch warm. Never put the baby in direct sunlight. Place the bowl in a larger box to keep it safe.
Soak dog or cat food and baby food in warm water. Supplement this with mashed hard-boiled egg yolk. Allow the mixture to sit until it has become a mash.
Put small amounts of this mixture in the baby's mouth when it opens it, using a baby spoon. Baby birds open their mouths wide and gaping, to make them more accessible. Place the food in the back of the baby bird's mouth, and wait for it to swallow before repeating. Never put liquid directly into the baby's mouth; the consistency of the food should always be that of a mash. Feed the baby every 30 to 60 minutes during the day.
Move the baby goldfinch to a cage environment when it starts growing feathers. Put sticks, branches and perches in the cage so the baby has a platform from which to jump and fly.
Put fruit, nuts, seeds, and vegetables into the bottom of the cage at this point, along with a dish of water. Maintain hand feedings, but restrict them to every 60 minutes, and then every two hours, and on, to encourage the bird to start eating and drinking for itself. Gradually wean the baby birds away from the hand-feedings in this manner.
Release the bird when it's able to eat and fly alone. Take it outside and place it on a fence or tree to begin its wild life.
Goldfinches can grow to be 5 inches in length. Male goldfinches are bright yellow with black caps, wings and tails; females are yellowish green.
Worms can carry parasites and should never be fed to baby birds. Keeping some breeds of bird is illegal.