While there’s still much to be learned about the whitetail rut, decades of deer research has taught us a lot about this special time of year. And much of this information will not only improve your understanding of the rut, but it can also make you a more successful hunter.
So as someone who loves to hunt the rut myself, I dug through the archives of deer research we’ve covered over the years and pulled out what I believe to be 10 of the most important things science has revealed about deer breeding behavior. But be forewarned, some of these discoveries may challenge what you’ve believed for years!
1. It Happens the Same Time Every Year
Want to know the perfect dates to take your rutcation in any given year? That’s easy! Just think back to when you’ve witnessed the best rut activity where you hunt, and take those days off — every year.
Decades of data collection by state wildlife agencies, as well as plenty of university research, has revealed that for any given area, the peak of breeding occurs at approximately the same time every year. It is not influenced by moon phase, weather changes or planetary alignments.
Photoperiod (length of daylight) is what triggers does to come into estrus, and the does are what dictates rutting activity.
Takeaway for hunters: The rut happens the same time every year, and you don’t need any special calendars, algorithms or apps to figure out when. So just go ahead and block those dates off with your boss for the remainder of your employment!
2. Weather Has No Impact
As mentioned above, weather has no impact on what dates deer breeding occurs, but does it impact what time of day it’s occurring? In short, no. The science is pretty clear that weather doesn’t impact deer breeding activity. A doe is only in estrus for 24-48 hours, so bucks don’t have the luxury of waiting for a cold front or better weather conditions to decide to breed. They have to strike when the time comes, and you can bet that once does start coming into estrus, the bucks will be on their feet looking for them.
Takeaway for hunters: When the rut is on in your area, ignore the weather forecast and just get out there as much as you can.
3. Moon Has No Impact
And just as weather has no impact on the timing of the rut or rut activity, neither does moon phase. Numerous studies have looked at the moon phases’ impact on both timing of the rut as well as deer movement, and neither are impacted enough to be noticeable to deer hunters.
These studies include a nine-year study of over 1,600 does in New Brunswick and a University of Georgia study that looked at data from over 2,500 does from South Carolina, Texas, Mississippi, Missouri, Maine, Minnesota and Michigan.
Both studies came to the same conclusion — there’s no correlation between peak breeding dates and the moon phase. And as you’ll learn when we get to #6, moon phase doesn’t impact what time of day the deer are moving, either.
Takeaway for hunters: Throw that lunar calendar in the trash and hunt when you can, especially during the rut!
4. Some Bucks Take Their Own Rutcations
Hunters aren’t the only ones taking rutcations in November. Multiple GPS-collared deer studies have shown that the majority of bucks (and some does as well), go on brief trips — or excursions as they are often referred to — where they travel an average of 1.5 miles outside of their typical home range for anywhere from a couple hours to several days.
While these excursions can happen any time of year, they increase during the rut. And it doesn’t take a Ph.D. to figure out why a buck may want to do a little traveling this time of year!
Takeaway for hunters: If that buck you’ve been watching all summer suddenly disappears this time of year, don’t be overly alarmed. He may very well be back in a week or two. And what’s better is that you may suddenly see one or more bucks you’ve never seen before this time of year!
5. Bucks Move More During the Rut
This one should come as no surprise to deer hunters. GPS-collared deer studies have consistently revealed that daily deer movement steadily increases from it’s low point in the summer months right up through the peak of rut.
That dreaded October lull you hear so much about doesn’t really exist. At least not in the sense that the deer aren’t moving. They’re typically moving more than they were in September, but likely in different areas from where you were previously seeing them.
So your odds of catching a buck on his feet during daylight hours steadily increases as we head into the rut and continues to do so until breeding activity peaks. Just another reason to be out there as much as possible this time of year.
Takeaway for hunters: The closer to the rut we get, the more deer are moving. If you aren’t seeing them, then it’s time to adjust your strategy and location.
6. But They Still Move Most at Dawn and Dusk
Even during the rut, when deer are moving more overall, peak movement still occurs at dawn and dusk. Again, pretty much every GPS-collared deer research study has confirmed this over the years, along with deer-vehicle collision data from across the county.
For example, of the nearly 18,000 DVCs documented by the Georgia Department of Transportation in 2017 (the last time this information was collected) at least 40% of deer were hit at dawn or dusk that year, which only accounted for six of the 24 hours (or 25% of the time) when an accident could have occurred.
Yes, your odds of intercepting a buck midday are higher during the rut than they were a month earlier, but still not higher than intercepting him at dawn or dusk.
Takeaway for hunters: The rut is the best time of year for an all-day sit in the deer stand, but if you’re limited on time, focus your efforts during peak deer movement times — dawn and dusk!
7. Older Bucks Do Most, But Not All, of the Breeding
There have been a couple different studies looking at breeding success of bucks and does by age, including one at Auburn University’s deer research facility in Alabama, and another at the University of Michigan looking at deer from Michigan’s 1,300-acre George Reserve.
Both studies saw similar results. While older deer do the majority of the breeding, younger bucks breed as well. Even button bucks sometimes!
Takeaway for hunters: Older bucks do most of the breeding, but don’t assume that young bucks aren’t getting in on the action. If you have a buck good age structure, expect breeding to be spread across ages — and don’t count on improving genetics through selective harvest.
8. Most Scrapes Are Visited At Night
I love finding scrapes in an area that I’m hunting. It lets me know there is one or more bucks using the area, and multiple scrapes tell me those bucks are likely revisiting the area on occasion to check those scrapes. However, research has shown there’s a good chance those visits are happening under the cover of darkness, outside of legal hunting hours. In fact, nearly 85% of scrape activity occurs at night.
Takeaway for hunters: While scrapes are a great indication of buck activity in an area, hunting directly over those scrapes may not be the best strategy to intercept that buck you’re after. Consider how those scrape locations fit into the overall deer movement picture, and try to set up between those scrapes and bedding cover to catch a buck slipping during daylight hours.
9. Fawns Can Breed Their First Year
We often hear hunters talk about the second rut, when does that weren’t bred their first estrus cycle come back into heat around 28 days later. And while that certainly does occur, in most areas of the country, there are very few does not getting bred that first cycle.
Often, that brief flurry of breeding activity we witness in December is actually some of this year’s doe fawns reaching the weight threshold that allows them to come into estrus. For northern deer, that threshold is about 80 pounds, and for southern deer, around 70.
And if you are seeing doe fawns come into estrus and being bred, that’s typically a good sign. It means the habitat is good enough to keep those deer healthy and at peak weight.
Takeaway for hunters: There’s nothing wrong with getting out there and hunting the “second rut” a month after the initial breeding activity, but don’t expect the same intensity of rutting behavior. If you’re lucky, a doe fawn or two will come into estrus and provide you with a great late-season hunt.
10. Most Bucks Only Sire One Fawn in Their Lifetime
This one probably surprised me more than any other one on my list. Despite all that effort that bucks put into the rut, at the end of the day (or by the end of their life), most bucks do little more than replace themselves. That was the conclusion from a long-term study conducted by the Noble Foundation from 1991-2001 on the King Ranch in Texas. Some bucks did better than others, with one particular buck siring 12 offspring.
Takeaway for hunters: It’s impossible to predict which deer will successfully breed and which won’t, so any efforts to manage deer genetics through hunting in a wild, free-ranging herd is futile.
Final Thoughts
The rut is an exciting time of year for deer hunters that can seem somewhat random and confusing at times. It can yield the most exciting hunts of the year, but also some of the most boring. But don’t let the unpredictability throw you off your game.
We know with certainty those deer are out there breeding at the same time every year. Daily deer movement is peaking, and the best times to see those deer on their feet are dawn and dusk. Use that knowledge to your advantage, and get out there as much as possible during this time. And if you aren’t seeing the rut activity you’d like, don’t be afraid to call an audible and switch things up. It may just yield the best hunt of your life!