I went to a seminar put on by Primos last year and they talked about the moon and elk. The moon does not effect timing of the rut which means hormones do not change with the moon phases. They will however do more activity at night and a little less during the day and you will hear less bugles during the day. But as I said above the hormones do not change and they are still pumped up during the rut and will still respond. Just try a hot cow call and that should get a bull or two runnin after you. Weather changes habits more than anything.