Factors That Can Impact The Rut
September 22, 2010
My phone rang off the hook with complaints about the 2005 deer season. Never before in all my years of being involved with whitetails had I heard about so many geographic regions that had problems with their hunting season as I did with regards to 2005. Of course, folks often formulate their own hypotheses to explain such phenomena, and usually their theories don't pan out. One hunter even proclaimed: "Why, we didn't even have a rut last year!"
Before I get into what happened in 2005, let's review what the "rut" really is. After all, there still seems to be much confusion about this topic. When I refer to the rut, I mean the entire breeding period of whitetails. Unfortunately, to most hunters the rut refers to only one rut activity: the "chasing period." But here is how the entire process works.
As bucks come into breeding condition, they first go through physiological changes during the "pre-rut" period, which takes place about two to four weeks before peak breeding. You don't see many bucks moving around during this time. Next, as the actual breeding period approaches, bucks begin to rub more and more as blood testosterone levels increase. At the peak level of hormone, bucks are aggressive and start making scrapes.
In order for breeding to work, though, the does have to come into estrus at the right time. If they are in good condition, this is a fairly tightly packed event. Bucks become ready to breed just before the does so that they will not miss those in early estrus. This means that the chasing period begins just about the time large numbers of scrapes begin to appear.
Chasing refers to bucks pursuing does that are approaching estrus. This is the preparatory period, not the breeding time. When hunters see this great amount of activity, they often mistakenly think it means the bucks are breeding. Also, bucks are easily lured to rattling and calling during this time. By the time an estrous doe actually picks a buck, however, movement among dominant bucks practically ceases as each buck sticks with his doe. This is when most bucks seem to disappear!
A buck stays with a doe about 36 hours. When you factor in normal variability among does, there may be a four- or five-day period in which mature bucks are practically invisible. After this time, they release their does and begin the search anew, causing many hunters to say, "The rut is back on!"
The three key factors contributing to the seemingly non-existent rut in many areas during 2005 were:
- Peak breeding dates were near the season openers in many states.
- High deer populations resulted in trickle ruts.
- Warm weather conditions reduced daytime movement.
When it comes to visible deer breeding and activity in 2005, I like to think of what happened as the "perfect storm." The vast majority of the northern part of the country has a November median breeding date, usually around Nov. 15. In 2004, the October full moon was late (Oct. 27), as was the one in November (Nov. 26). That made breeding occur a bit later in 2004 in regard to most opening days (mid-November).
Deer probably did not actually breed that late, but more likely somewhere after the middle of the month. In 2005, both the October and November full moons were in the middle of the month, a more normal condition. Also, weather conditions during the fall of 2005 were, shall we say, weird! Warm, snow-less days greatly restricted deer movement. When you add in the fact that most deer populations are now at or above carrying capacity, this created the perfect scenario for a "trickle rut" in many locations.
All of this created the perfect storm in many deer hunting situations. Bowhunters usually have an advantage by getting into the woods before the deer are disturbed by the throngs of gun hunters who follow. But in 2005, warm weather generally restricted deer to nocturnal activity. Our camera studies confirmed this. Since the gun season in many areas opens around the middle of November, hunters missed the all-important chasing period. Bucks were "locked up" with their does at this time. Again, if you couple this with warm weather -- and in many areas good food conditions along with a lack of thermal stress -- you have a recipe for a poor season.
What does the future hold? As deer populations increase even more, and as climate warming continues, we can probably expect to see more seasons like 2005. One way to counter this is to examine the way you hunt and determine what you can change to compensate for these issues. In spite of a great deal of difficulty, I managed to harvest a trophy buck in four of my five hunts for North American Whitetail Television. In order to do so, I had to shift tactics to fit what was happening.
For example, once I determined we were in the peak of breeding on my Texas hunt, I relocated to a major funneling habitat feature and waited patiently for the bucks to relocate themselves. On the last evening of the last day, the woods were filled with bucks and I was in position to take advantage of this short period!
Three days later, the bucks once again disappeared. To better help you understand what deer are doing in your specific area and what tactics to use, we plan to include a graphic in each of our 2006 television episodes showing what phase of the rut each member of the team was hunting at the time. I hope this will help!