Deer hunters often try to tie deer movement to the phase of the moon. Some hunters even plan their hunting trips around it. Most hunters believe the phase of the moon has at least some effect on deer movement.
The team over at MeatEater wanted to determine whether the moon phase affects whitetail deer movement.
GPS Collars Don’t Lie
For years, studying the moon’s influence on deer movement involved record-keeping by dozens of hunters over hundreds or thousands of hunting trips. That data was then painstakingly collated and analyzed for patterns. But in recent years, GPS tracking collars have been used to provide measurable data on when and how far those deer really move, all day, every day.
In 2017, Penn State published the results of a study using GPS collars on deer. Data were collected from adult deer movement in October of 2015 and again in October of 2016. Moon phase varied from new moon to full moon and phases in-between. The results yielded no statistical difference.
A Guide’s Perspective
Guide and author Remi Warren seems to agree. Guiding for ten weeks during the fall, he sees no real correlation between hunter success rates and the phase of the moon. Instead, knowledge of the animals’ behavior is more important. His clients’ success rates were the same each week, regardless of the phase of the moon.
He does, however, notice some relationship between bear activity and the new or full moon. He observes that during a full moon, bears are not seen during the day in areas where they are found during a new moon. Warren states that the animals may still be moving in during daylight, just in different areas.
Observational differences might be responsible for the disconnect between hunter perception and biologist studies. Visibility and vegetation, where the deer is moving, even the presence of an observer might yield different results. The deer movement might be of the same magnitude but in a different place.
Dr. Grant Woods, an expert who runs Growing Deer TV, states it pretty clearly. Throughout his career, he has seen that the more advanced the deer science becomes, the less correlation between deer movement and moon phase.