In my opinion, after the first few weeks of opening season, birds that are even pressured lightly get used to most calling. After that, I only bring 2 calls. My most used call is a crow call or locator call. Second is a mouth call for turkeys just in case. After that 2 week period, I will just begin stalking the turkeys instead of calling them. I have never called a turkey in during the May season. I have tried many times, but lately I just figure it isn'rt going to work.