These feathers are trash and aren't much good for anything. The stems are thick, the tips are wide and the fibers aren't even. About the only thing you can do with loose marabou is make cat toys out of it. Strung marabou, wooly bugger marabou and marabou shorts all come from turkey. The very finest and tiny feathers are called marabou shorts.
Grizzly marabou comes from chickens.
One trouble with working with this material is sorting the bad ones out. Broken tips, uneven feathers or thick stems are useful only for making pillows not flies. It is selected from marabou shorts. You may also use the tip of the marabou short for the same effect. The above feathers can be used as wings, shucks or for bodies if tied correctly.