I am trying to get the achievement 'Set Them Free' which requires that I disable 5 brain cages on Blood Dragons. I've completed the story missions and during that only encountered a few such Blood Dragons, and have destroyed the brain cages pretty easily. However now that the story missions are over I can't seem to find any Blood Dragons still wearing the cage.
Is there a place I can go to find Blood Dragons with brain cages?
I still have a garrison left unliberated but mostly everything else has been done. Have I just missed some crucial Blood Dragons during story play through?