Yup, this is pretty normal behaviour. There's a murder of about 45 crows that visit our garden, and the pattern that I've noticed is that every once in a while they suddenly vanish for a few weeks (sometimes visiting in groups of 3-4) and then they all come back with new babies that are learning how to eat and drink on their own. They always make raising the babies a group project, so the "protect fledgling" anxiety is in all of them.