Can you help abandoned birds in nest?

First, you need to get a can of good quality cat food....When you approach the nest, the chick will automatically open it's mouth for food. Use a popsicle stick or something other than your hands to put food in it's mouth. Small bits at a time. Do not overfeed it. It's better to give several small meals a day. I would say about 1 tablespoon per chick. The canned catfood contains a lot of water so it should not get dehyrated. Keep the chick in the nest if you have it. If you don't, get a shoebox.....and fill it with straw, or shredded paper (enough to keep it soft and warm. Also, its best NOT to bring it inside...keep the nest in the natural environment. You can also feed them smashed up earthworms if you have the stomach for that! And remember that no matter what you do, sometimes they don't make it so just do what you can and let nature take its course.