I took the challenge of tying some shark flies for Mako and none of them had any chicken feathers at all. The bulk of the fly was synthetic. The only natural material I used was rabbit. Big hooks 6/0-10/0, 6-8" length min. and predominately red and orange were the most prescribed requirements. They caught 5 mako on them so the fish liked them.
You can take a look here for the bulk of them ........
http://s292.photobucket.com/albums/m...shark%20flies/