German Shepherd never barks-ever

Question
I have a 3 year old German Shepherd intact male. We adopted him from a family member about a month and a half ago. He has not barked once. Not when people knock on the door, not at other dogs even if they are barking at him-he never barks. The only time he has really made noise, is when another intact male tried to mount him. He growled. Not that I want him to start barking at everything, it just doesn't seem normal. He has a great temperament, and is a very well behaved dog. Is it normal? Is he still just adjusting to his new home?

Answer
Typically Shepherds are fairly vocal, often more whining and howling than barking.  Some dogs are much quieter.  My Lab Holly has never learned to bark to let me know she wants in.  It is a wonder she didn't freeze last winter when I would let her out and get busy answering questions and forget about her.  That is with an older dog that shows her how well it works for her.  

He may bark more as he becomes more comfortable in your home.  Shepherds often are slow to accept a new home.  

Consider having him neutered.  There is no real reason to keep an intact male, and many good reasons to neuter him, starting with less chance of cancer later in life.  It also reduces the possibility of a sudden bolt out the door or over the fence when you didn't realize three was a female in season a mile upwind.  He may or may not make it back from such an adventure.  Even if he does, I am sure you don't want to be a part of the problem of slaughtering millions f dog every year for lack of homes.