For the colorful feathers like in your pic, you could use ye olde big white turkey feathers. Buy 'em in
white and dye them or buy them
already dyed if they have your color/s. Probably run you 25 cents to 1.00 each.
You are talking some
major bucks for pheasant feathers that long.....
If these only have to look good from a distance, like on a stage, or on film, you might want to look into making something.
I have seen some "totally fake" pheasant feathers, howbeit, not this long, in the floral department at Hobby Lobby. Appeared to be made of some kind of thin stiffened fabric. There were no individual filaments/barbs like a real feather.
I think it would be doable to make using some thin, cheap muslin dyed to the background color of the feather
Stiffen it with some kind of glue solution sizing,
Make a pattern for the feather and mark it off on the stiffened fabric
Glue a thin wire down the back center of each
Paint on the dark slashy marks on the fronts.......
Since the feather shape is thick end/thin end, when you laid them out on the fabric one turned one way one the other, and say your feather is about 45" long, you could get quite a few out of a 1 1/3 yards of fabric and would be fairly inexpensive, though labor intensive
If you have a craft store near you that sells floral arrangement items, check them out to see if they have any fake feathers and examine their construction.
Shylaah