It doesn't spawn, you can pick infinite feathers from that one bird. What I found to be the fastest way was to summon a spirit larupia, use its teleport, run to the eagle cave nearby, use the eagle network to get to the desert, pick an inventory full of feathers and bank at cwars. I got about 800 feathers/hour that way, running from shantay pass was about 600. This sounds like the best way to do it, I only need about 200 to start with so it shouldn't take long. Thanks guys. :D looks like the quickest way so far. I use to just run from the shantay pass, fill up on feathers, tele to al kharid palance, use the chest at shantay's then run to the phoenix from there.