Experience has taught me that for coyote hunting this is what works best, at least for me. Something in the lower power variable magnification ranges, definetly no higher than 4.5-14 or so
3.5-10 or 3-15 is better, and with as wide a field of view as possible, hence an Obj. lens of minimum 40mm up to 50 mm( bigger is better). Eye relief, cheek weld and eye-box are paramount also. This will set you up for anything you will encounter, close in moving targets coming to a call, further out targets either stationary or moving and longer range stationary targets, all shot at from various positions. Get yourself a good range finder also if you intend to shoot longer range. Parallax adjustment is not really necessary and please do yourself a favour and get almost anything other than a Vortex.