Before, waterbird at Russian river was extraordinary (13)
I believe the answer is:
preternatural
'extraordinary' is the definition.
(similar in meaning)
'before waterbird at russian river' is the wordplay.
I cannot quite understand how this works, but
'before' could be 'e' (I've seen this in other clues) and 'e' is found in the answer.
'at' is within the answer.
'river' could be 'ural' (Russian river) and 'ural' is present in the answer.
This explanation may well be incorrect...
'was' is the link.
Can you help me to learn more?
(Other definitions for preternatural that I've seen before include "Weird - extraordinary" , "Very unusual" , "Abnormal" , "beyond what's normal" .)