Hunted the opening 5 days in NW CO and there was very little bugling. We heard a little each day but the bulls definitely were not fired up. It was a tough hunt between the heat and the full moon. I'm not sure what had a bigger impact the heat or moon phase? It was 94* on Saturday and 90* on Sunday. Saw several herds of cows without a bull and the herds that did have a bull with them it was not a mature bull. I wish I could be there now after the cooler weather has arrived. We actually saw the best movement on the last two days which were the hottest of the five. Fingers crossed for cooler weather next year on our hunt.