ZEBRA DOVES - 10. Twelve days old fledgling

On the 23rd August at 8.30 am there was a cooing around the old nesting tree. Suddenly a bird flew to a tree nearer to me. It was one of the two fledglings, then 12 days old. One of the parents was nearby. Five minutes later both flew off. Was the fledgling cooing or was it the parent bird? Was this the younger fledgling? Had the older become independent? I have since not heard nor seen the doves around. It looks like goodbye...