If you have the calls already, I would just use them. I am by no means a master at them, but I do get the yotes to come in. Blow your calls and find a noise that sounds like it could be something dying. It doesn't exactly have to sound like a rabbit or anything in particular just a good "waa" like a baby crying. Then just make that noise over and over for 15 seconds or so and wait for a bit before doing it again.