By moving the call around and changing where your teeth are, blowing differently, cupping the call or leaving it open. You change the sound, the rythm, the volume. The raspiness. The guy using the call.
Personally I do not buy into the theory of immitating a specific animal I think you create a sound that is different and that difference is what attracts a coyote. I do not think coyotes sit around and say, hmmm that sounds like a rabbit, or a fawn, no mabbe a squirrel, or mabbe a bird. it is more like hmmm sounds like it is hurt, I'll eat it, and I'll eat anything..
People use sounds of animals from Africa/Asia, sounds never heard by a coyote here.
Ricks calls are great, and can make any sound you want.
Carl
You do not blow a call you play it