Slow end of September bugling?

[doct]

Each year I go bugling and/or elk hunting right in the middle of September. Elk are screaming,,,,,,,awesome! This year, however, I went the last week in September and the bugling had slowed down DRAMATICALLY! Don't think they moved out of the area, maybe they slipped out of the rut pretty fast! I'm stumped,,,,,the moon, the weather? I live in Utah,,,,,anybody else find it slow? Any thoughts, because next year I'm going right in the middle of the month!