I think Sokoly tranlates to Falcon, however 'Falcon' sound wrong, it needs to be a three syllable word.
a couple of cheats....
Hey! Hey! Hey proud falcon! (add an adjective)
Hey! Hey! Hey hawk flying! (add a participle)
Or work backward from the rhymes,
omijajcie góry, lasy doły "As you pass by mountains, forests, valleys..." (now work backward from valleys.... or whatever word you put there)