It's either Gadwall or Pintail. I use mallard and gadwall most in these ties but also use wood duck and pintail. Slight variations in them all but all work very well. I tie these mostly with either black or red thread using 8/0 UNI thread. Red thread is actually Fl. Orange and only comes in 8/0 for some reason but thread glows under uv light and fish see it better, my favorite thread to use.