Black swans were found from Mordor and northward into Wilderland, as far as the southern reaches of Mirkwood. They were also quite common in the river valleys of Nûrad and Rhovanion, especially along the River Anduin. They were large for swans and had been known to mob and overturn boats, usually because the vessels had come too close to the swans' huge nests.
References
- Retrieved from [Realms of Arda]; original reference: [ICE MERP 2012]