Yeah, a third avian is fine! And all the Rangers can fly if you'd like, since we all have dragons as the primary animal. 

So, just to recap, these are the current colors claimed:

Me (Cap): Green, Purple
Crimson: Pink
Winds: Black
Forsythe: Red or Copper
Gisk: Blue
Duthguy: Not specified

I hope I didn't miss anyone. Assuming we go with this roster, all original seven Ranger roles are filled, though Duthguy hasn't posted in this thread in a while, so I'm not sure if he's still participating. If not, then we could start out with five Rangers and then someone could play a sixth later on. Alternatively, we could say there were six Nanosuits instead of seven and the sixth person could become the new Purple Ranger after Bandora's defeat or something. If we don't get any more interest in this RP and it ends up just being us, I will probably just play that sixth Ranger myself. Since Bandora doesn't have an actual flesh body anymore, she could target one of her descendants in Japan to be the "host" inside the suit, perhaps an older woman who looks similar to Machiko Soga, the actress who played Bandora in Zyuranger. Then after her defeat, the Purple Nanosuit is purged of the witch's mind, and perhaps the teenage granddaughter of the former host becomes the new Purple Ranger and joins the other five Rangers. This could be around the time Lord Zedd surfaces, and while a remnant of Bandora still exists independent of the suit, she no longer has any Ranger powers, only her blood magic and sorcery. 

Much later on, Zedd and Bandora could concoct a scheme to try and take the Purple Nanosuit back, including secretly infecting the Purple Ranger with a virus that gradually saps her power away. This energy then condenses and exits her body as purple snot, becoming a slimy symbiote similar to Venom in Spider-Man. Ultimately, this new being could gather enough power to become a version of Ivan Ooze.