There are lots of clues for finding babies... sound, behavior. If an adult bird is carrying food instead of eating it's most likely nest-bound. And if there's a bird yelling or doing the feed-me flap for sure it's a baby. I saw the starling with mulberry one day and tried to find the nest. That came a couple of days later, nest in metal tubing at boat basin. Usually sparrows pick tubing for their nests. This was different. It was by accident that I saw this. You have to be in the right place at the right time. The baby sparrow was also near the boat basin. The yellow craw marking is so noticeable. This baby was picking at a small piece of turkey. If it's available it's going to be found and eaten. The grackle didn't seem to know what to do with the worm. Juvenile robins are adult-size, but with speckled breasts. They can pick a bit, but chasing papa and yelling for food is the more successful option. Just listen for the "feed me!" call and you'll find a baby robin.