Birds do communicate in their own ways and we can hear some of their calls. The babies will just go to where they see the parents and then follow them no verbal commination needed.

I have been watching some owls that made a nest in my backyard bird house and recently the babies left the bird house to join the mother in a large tree where the bird house is hanging. I'm wondering how the mother communicates with the babies. For instance is she able to let them know she's looking for food for the babies? And how does the mother let the babies know if she decides to leave my backyard tree and go to another location? I ask this because today they suddenly all disappeared after several months of living in my birdhouse and the tree where it's hanging. This question could apply to other birds and animals as well and I'm wondering if the mother makes sounds indicating she wants the babies to follow her. I never heard the mother make a sound all the time she was nesting in the bird house but I'm thinking she must be able to make some sounds