I turkey hunt in several states every year, and only miss a day of season if the weather is bad. That said, I've only had a few coyotes come in to turkey sounds while calling. I'll share the most interesting story with you.
Two years ago while turkey hunting I had a pair of coyotes come to the base of a tree that a gobbler was roosted in. I could see the turkey,(still in the tree) and the coyotes at the same time. It was obvious from the coyotes reactions that they had come to investigate the gobbling, as I had not made any calls yet. One of the coyotes even looked up the tree. When the turkey saw the coyotes he shut up, but did'nt fly. The coyotes smelled around, then moved off in the oppisite direction from where I was set up. The turkey remained silent for about 10 mins after the coyotes left, then he gobbled a few more times, and flew down in a clearing abour 20yds from me. I shot the turkey as soon as he hit the ground, and he began to flop. All of a sudden one of the coyotes came running in at full speed, grabbed the gobbler, & tried to take off with him. I then shot the coyote as he was dragging the still flopping turkey. After the shot the coyote did'nt drop the turkey for several more yds. When he finally turned loose he made it about 50yds and went down, he still had the waddles in his mouth.