Each year deer hunters spend an inordinate amount of money trying to predict the whitetail rut in their area. They purchase moon guides and hunting apps, listen to online blogs and more. It seems as though every year someone has reinvented the wheel, providing a new annual rut prediction tool.

Many people swear by these tools and others swear by traditions. Some say their favorite time to hunt the rut is Veteran’s Day (November 11) weekend, while others don’t even go out until the week of Thanksgiving. The truth is, studies have shown the rut is about the same time every year. This varies widely based on your region, but annually, the rut will occur about the same time each year.

We know the gestation period for whitetail deer is roughly 198 days. If we are able to witness the birth of a fawn and count back 198 days, ultimately, we can depict the date of conception. For the majority of us, finding a fawn can be difficult let alone finding one being born. Hunters are much more likely to harvest a pregnant doe in the late season or perhaps find a road-killed doe.

If so, and you are able to verify the date that the doe and fetus died, you can determine the date of conception with a fetus scale ($6.95) available from the QDMA (Quality Deer Management Association). By measuring the fetus and using the Julian calendar on the back of the scale, one can predict both the date of conception and the date the fawn would have been born. This information can help predict the timing of peak rut, especially when measuring multiple fetuses is possible.