Lunar Cycle Does Not Affect Deer in Pennsylvania

There is a study circulating the internet which many claim finally puts to rest the theory that phases of the moon influence deer movement. I’ll bet you know hunters who hunt with the moon, or are one yourself. The study was conducted by an undergraduate student at Pennsylvania State Agricultural College and published to the Deer-Forest Study website blog. The project claims to “help forest and game managers better understand how deer affect forests so they can make better management decisions” and is funded by Pennsylvania Game Commission and Bureau of Forestry. The study is a wide ranging research project on the many interactions of white-tailed deer and forest ecology. The study in question focuses on deer movement during phases of the moon.

You can read the full blog of the study here.


Using data from GPS collared deer, the student compared the movements of deer with the lunar calendar. The two immediate issues we found in the methods were a) no mention of sample size, and b) study was only for a year. There are many other factors that affect deer movement and conflict with lunar findings like cloud cover or forest density. These things were not mentioned. Due to study constraints, bucks were also excluded from the analysis as their GPS collars did not record data as often as the does on the study.


The study concludes that the small changes in deer movement are  “not statistically or biologically significant because deer can travel hundreds of meters in any given hour of the day”. The finding was that the deer traveled 6 meters more per hour during a new moon cycle.

deer traveled
Deer data represented. Taken from


As this study is not peer-reviewed or even published through a main stream journal, it should be considered preliminary or introductory. The preliminary findings are interesting and we are very curious to see if these hold up to a more thorough analysis. Overall, this study cannot be considered conclusive and may not apply to most western deer. Pennsylvania deer live without their historic predators and it isn’t too much to suppose the deer have lost some of their predatory response behaviors. Predator response is one of the strongest behavior influences and most likely the cause of moon-associated movements (though this has yet to be studied thoroughly).

So, if you hunt with the lunar phases, continue as you please. For most of us, we hunt when we can regardless of the moon phase.

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