Stemming the Aggressors

Objectives
Glorthal Stiffbeard at Frosthold wants you to kill 8 Frostfeather Screechers and 8 Frostfeather Witches.
 * slain (8)
 * slain (8)

Description
Damn harpies. We've beat that bunch into submission more times than I can remember... and they stay quiet for a time after each bout. This time, I'd thought that maybe it sunk in.

Apparently not.

Their memory may be a bit short, but if their numbers are thinned enough, they'll keep to themselves. Head into the valleys in the north and east and clear out a fair chunk of them for me, will ya?

Progress
Persistent buggers... can't ever seem to rid ourselves of all of them. They breed like rabbits.

Completion
It's dirty work, I know, but we appreciate it. Now what was the name the scout mentioned... Sirana?