October 18, 2012
The rut. Mere mention of the term stirs the blood of any die-hard whitetail hunter. It's a dynamic period when the woods come alive and even the cagiest mature bucks are out and about during daylight hours. The down side, we've all been told, is that predictability goes right out the window. Those local bucks you've been after all fall fan out across the landscape and it becomes more a matter of chance than preparation or scouting; or does it? Recent studies suggest that might not necessarily be the case.
Last October in this column, I discussed two different strategies bucks can employ to locate a mate. Levy walks or excursions are what we typically think of when we envision the rut. Bucks leave their core areas, traveling far and wide in search of a hot doe. And it's an effective practice when estrous does are scarce. But how often is that actually the case?
Research indicates most states have a rut that is quite regular, occurring at roughly the same time every year. And considerable research shows it is fairly synchronous, with most does coming into estrus within a fairly narrow window of time. This is especially true of populations that are well balanced in terms of sex and age. So, in areas with moderate or high deer populations, finding a hot doe during the peak of the rut shouldn't be all that difficult. In such cases, an alternate strategy called a Brownian walk, which involves revisiting the same areas frequently, should be more efficient.
The Latest Findings
Researchers at the Caesar Kleberg Wildlife Research Institute in South Texas tested this hypothesis by capturing 106 adult bucks, fitting them with GPS collars and tracking their movements over a four-year period, recording locations every 15-20 minutes from late October through mid-February. They found that bucks did not wander widely during the peak of the rut. In fact, on average the bucks used only 30 percent of their home range.
Even more interesting, most bucks had two or more focal points — between 60 and 140 acres in size — within their home ranges that they re-visited frequently, about every 20-28 hours. Researchers also found the focal points of several individual bucks overlapped during the peak of the rut. Because does come into estrus for about 24 hours, researchers speculated bucks might be spacing their visits to assess female receptiveness.
Bear in mind, however, that things are rarely as simplistic as we hunters would like them to be. If you graphed the number of does and when they come into estrus, it would appear as a bell curve, with the majority being in the middle and declining numbers on either side. The farther you get away from the peak of the rut, the fewer does in estrus. But there will still be a few receptive does well away from the peak, both earlier and later. In essence, hot does are a scarcer resource at these times, so making far-flung excursions may be a more effective strategy for finding them.
The Texas researchers also looked at this and found the proportion of males exhibiting random walks during the breeding season followed a bell curve very similar to that of peak conception dates. Early in the breeding season, bucks had to travel farther to find does, but once they did, their movement declined and re-visitation to focal points increased.
They also found some age differences. Yearlings and mature bucks were least likely to go on excursions, particularly during the peak of the rut. In the case of yearlings, they attributed this to less experience, smaller home ranges and less fat reserves, all of which increase the risks associated with venturing too far from home. They speculated that mature bucks are more experienced and should know where to find does, which is supported by the higher re-visitation rate.
The outliers were 2 ½-year-olds, which were more likely to continue excursions through the peak of the rut. Researchers conjectured this might be due to inexperience at knowing where to find does, as well as increased conflicts with older males.
The Bowhunting Application
These results might prompt some bowhunters to re-think their rut hunting strategies, especially if they're after a particular mature buck. Striking out in search of greener pastures or shifting to travel corridors might get you more deer sightings, but odds are better those will be middle-age bucks, those still relatively naive 2 ½-year-olds that so tempt us. And if you're content with a good representative from this age class, that might be the way to go.
If you have loftier goals, you may be wise to re-double your efforts where you observed that big buck earlier in the season, either by eye or camera. The research suggests those bucks stick pretty close to home, even during the rut. They may wander a bit before and after the peak of the rut, but older bucks seem to know, more than younger bucks, when it's time to get up and move. They may sit out the prelude, waiting for the main act. If you make any moves, they should be to areas of doe concentrations within the same vicinity. That might be dense bedding cover or a concentrated food source.
Hunters and biologists are continually trying to unravel the mystery of the whitetail deer. Yet each new discovery seems to come with it as many questions as answers. Greater knowledge of these miraculous creatures helps us become more successful hunters while also humbling us with a greater realization of how little we really know — and fueling our insatiable quest for more.