Drops from
Navarn Steppe
Tooth Fairy Forest
Loopy Tree Forest

Killing Feather Wolves on Arsha with a Loot Scroll, I was able to get 90-105 an hour. (With a 250 Kutum AP Horseback Tamer alt)
**If you don't want to go to Arsha, but have a tent and don't mind wasting 50 mil an hour, buy the Adventurer's Luck buff which gives +50% drop rate.**

Best Feather Wolves rotation: South of Navarn Steppes Node Manager.