During the spring breeding period, gobblers will often respond spontaneously to non-turkey sounds. This is referred to in turkey hunting as a shock gobble. Shock calls like coyote howls, crow cawing and owl hoots can all elicit gobbles from tom turkeys.
The most popular shock calls for turkeys are crow calls and owl calls, but any call that is capable of making a sharp sound can work to get tom turkeys to respond during the spring mating season.
Video: Tom Wiley, the founder of Flextone Game Calls, gives tips on how to use the Flextone Crow Shocker for locating turkeys and crow calling. via Trapper & Predator Caller