Given the raven attacks on Shadgard story line, it might be a good idea to add a raven culling task to the town barracks (1) to further establish anti-netherim sentiment as part of Shadgard's identity and (2) to grant a little spending riln for those characters who are taking on ravens instead of low level infested.
Since the ravens are giving out enough exp on their own, it should just have a riln reward (like the locksmithing task in the warehouse). I'd suggest having a 10 minute cool down kill 15 ravens for 100 riln or a 1 hour cool down kill 50-100 ravens for 1000 riln. If you're feeling generous give both and don't worry about the kills being double counted by both tasks, if the double counting would bother you, don't have both tasks and save yourself a coding headache.