Is Predicting Wildlife Behavior with Solunar Calendars Fact or Fiction?

It only takes a sportsman a few trips outdoors to notice that wildlife exhibit increased activity levels during certain periods of the day. In the case of whitetail deer, the most active times typically occur around dawn and dusk, with periodic increases in activity overnight. In the early 1930’s, a man by the name of John Knight sought to get a better understanding of why wildlife was more or less active during the day or night. Using lunar phases and the time of sunsets and sunrises, Knight developed a method of predicting times of increase wildlife activity and called the method a ‘solunar table.’ Currently, many websites offer solunar tables in an attempt to provide sportsmen with an edge when it comes to bagging that big buck or snagging a monster bass. But are these tables legitimate? 

There is some basis in the theory that lunar phases can influence wildlife movements, however it is a tad more complicated than just using the moon phase (Webb et al. 2010, Sullivan et al. 2016). In a recent study, a solunar table proved to be relatively accurate at identifying peak activity times of whitetail bucks (Sullivan et al. 2016). However, it is fairly well known that dawn and dusk times can influence deer movements. The use of moon phase was not successful at identifying the overall activity level of deer, whereas deer were not more active during nights with a full moon as opposed to a new moon (Webb et al. 2010). The reason for the inaccuracy may be due to the fact that a solunar table does not address fine-scale climatic changes (i.e., weather) that influence the amount of moonlight available each night. 

It is important to consider the nightly weather, as well as a solunar table. While a solunar table may dictate an increase in activity due to a full moon, if the night is cloudy or there is inclement weather, wildlife may not be as active as expected. The reason for the increased activity during a full moon has more to do with the increase of available moonlight rather than the actual lunar phase. The increase in light associated with a full moon increase vision clarity enabling deer to more easily detect predators, forage and landscape features.

Overall, a solunar table can provide a decent tool when planning the coming hunt. However, it is important to remember that solunar calendars are not completely accurate in that they do not provide fine-scale adjustments for environmental variation; they do provide a baseline for periods of increased activity. Be sure to incorporate daily and nightly weather variation in conjunction with the solunar table to more aptly plan your next outing.

Sources:

Sullivan, J. D., S. S. Ditchkoff, B. A. Collier, C. R. Ruth, and J. B. Raglin. 2016. Movement with the moon: white-tailed deer activity and solunar events. Journal of the Southeastern Association of Fish and Wildlife Agencies 3:225-232.

Webb, S. L., K. L. Gee, B. K. Strickland, S. Demarais, and R. W. DeYoung. 2010. Measuring fine-scale white-tailed deer movements and environmental influences using GPS collars. International Journal of Ecology, published online: DOI/10.1155/2010/459610.