Drake making high pitch squealy noise

[DuckWild]

So, I have 4 drakes and no females, and my Buff drake has started constantly making a squealy/squeaky/high-pitched noise instead of quacking like my 3 others. Searches online pull up mixed opinions. He doesn't seem to have any discharge/difficulty breathing. Is this a normal behavior? Some things say they make it while breeding, but I have no females for him to breed with.

 

[CherishedFowlGuardian]

Could you please send a video of the drake making the high-pitched noise?

 

[CherishedFowlGuardian]

Drakes don’t quack.Could you send a video of the other ducks?