5 of 5 baby blackbirds have fledged the nest this afternoon,  the parents are still around but not staying much in our garden yet there is one fledging that wont leave the place of the nest and is just sitting on a branch its still alive but when the parent comes into the garden its not tweeting or flapping around. Can someone tell me why and if or when it will move as it hasnt been fed for about 5 hours.  Also do the parents know its there?? Thanks