Take the calls. You just never know what might raise enough curiosity to get a buck to close the gap. As a last resort, I pulled out a grunt call in Nebraska several years ago the first week of September! I had a good buck browsing in a hay field in front of me for most of the evening at over a hundred yards. As he started to exit the far side of the field I began grunting several times and he came right to me and I brought home a 135" 8pt. that weighed over 300 lbs. on the hoof. I have also rattled in bucks in early October. In '04 I took a 145" buck on Oct. 16, by rattling after he disappeared over a ridge. I use the calls as a last resort usually that early, but what do you have to lose if the deer is leaving anyway? Just use passive grunts and very light rattling if necessary and cross your fingers. Also, I think it is very important that you only call when the deer can not easily see your location. Wait until terrain or brush etc. obscures his view and NEVER call directly towards the deer.If he is in the wide open, wait until he looks away and call each time he looks away. That drives them nuts sometimes and even the big boys cant stand not coming closer for a better look. Good luck.