Buckmasters Magazine

The Day Shift

The Day Shift

By Bob Humphrey

What does science say about big bucks moving in the middle of the day?

My morning started badly. Before I even left the cabin, the lid blew off my thermos, splattering me with scalding cocoa. Then my guide and I were late leaving camp. Thirty minutes down the road, we were nearly to the pull-off when we encountered another guide broke down on the roadside. Of course we stopped to render assistance. More than an hour after full daylight, we finally pulled up to my stand on the ATV.

As the guide motored away, I prepared for the abbreviated day’s hunt. Reaching into my pack, I felt a warm, wet sensation. My thermos lid had come off again, this time saturating my pack’s contents, including my gloves and hat.

Had I been hunting back home, I might have called it a morning. But this was Saskatchewan, and I knew that, despite the tumultuous start, the best was potentially yet to come. I knew because I’d been able to watch daytime deer activity for three previous days from this stand, and because this was my third trip to the Prairie Province.

Deer movement increased throughout the morning, but it was mostly does, fawns and younger bucks, the latter of which repeatedly harassed the does. The rut was kicking in, but for three days I’d seen only smaller bucks.

Mild anxiety turned to nagging doubt when, by noon of day four, I still hadn’t seen a shooter. Then, it happened.

I first heard a grunt in the dense coniferous underbrush. Then I caught a glimpse of heavy antlers. Rather than rushing recklessly in, the buck circled downwind and paused in the thick copse, waiting for the restless does to settle down. Then he approached in the slow, deliberate manner of a mature buck. My day suddenly got a whole lot better.

Ask almost any Saskatchewan outfitter about the best time to hunt, and they’ll tell you “10 to 2.” The same goes for a good many folks in other parts of the country, especially if your specific goal is tagging a mature buck. But how much of that is folk tale and conjecture? Is there any science behind the magical midday period?

SURVEY SAYS

There’s been a ton of research conducted on deer movement (or the lack thereof), and it confirms what we already know: White-tailed deer are most active around dawn and dusk, or crepuscular hours, as the researchers put it.

Most contend this pattern helps them maintain optimal body temperature and minimizes the risk from predation.

There are, of course, exceptions to every rule. The above generalities tend to be most accurate during average conditions and with all other things being equal. Often, however, neither is the case. For example, temperature can have a profound effect on deer movement. Research on Northern deer has shown that late-season activity drops off considerably when daytime temperatures rise above the mid 40s. And, to a certain extent, the opposite is also true: The colder it gets, the more deer move.

Daylight also plays a role. Deer move mostly in low light, so does that mean they move more on heavy overcast days? There is some evidence to suggest they move later into the morning and earlier in the afternoon on such days. It’s possible their daylight receptors are fooling them into thinking it’s earlier or later than it actually is.

The rut is a factor, too. Deer move more and, thus, will be on their feet outside of their typical patterns.

When biologists plot daily activity patterns (see chart above), the graph usually depicts peaks, known as bell curves, with highest activity occurring during relatively short intervals around dawn and dusk. The aforementioned examples of midday fall outside those peaks but still don’t make a strong case for hunting during the middle of the day.

There are exceptions that do, and one of the most famous is Quebec’s Anticosti Island. Most who have hunted this island, located at the mouth of the St. Lawrence River, have witnessed a true aberration of whitetail behavior. Though movement peaks during twilight hours, Anticosti deer move throughout the day during peak hunting season, despite a considerable level of hunting pressure.

Some have suggested the increased daytime movement is because of a complete absence of natural predators on the island. However, I’ve also hunted there in August, when daytime temperatures sometimes soared into the 70s. Then, daytime deer activity was much more typical, occurring predominantly at dawn and dusk.

Perhaps temperature is a more important factor than risk of predation. And there’s further evidence of that north of the border.

ECONOMICS 101

It might not be hard science, but my own observations have been consistent with those of virtually every Saskatchewan hunter and outfitter I’ve spoken with. The colder it gets, the more deer move. And they move best between 10 and 2, despite living with the constant threat of coyotes and wolves.

Survival in the wild can sometimes best be explained in economic terms, namely the cost-benefit ratio. Deer obtain energy (benefit) in the form of calories by feeding. However, the very act of moving about to feed burns calories (cost). To survive, deer must obtain more calories than they burn. That becomes more difficult as temperatures drop, because more energy is required to obtain calories. All other things being equal, the most energy-efficient time to feed is during the warmest part of the day — midday.

Again, all other things are seldom, if ever, equal. Midday movement also increases the risk (cost) of predation. That’s a big reason why deer move at twilight during average seasonal temperatures. There comes a point, however, when the benefit of maintaining body temperature becomes more important than the potential cost of being eaten. Otherwise, deer would have become extinct several million years ago.

THE RUT

As previously mentioned, the rut also plays a role. Most of the research has concluded that deer, especially bucks, move more during the rut. No surprise there. Still, most of this increased daytime movement, according to research, is only smoothing out the bell curves, and not occurring significantly outside the typical dawn and dusk peaks.

It’s important to keep in mind that these are averages. Most of the bucks might be moving in and around dawn and dusk, but their primary objective is finding a mate — and some are on their feet well outside the morning/evening peaks. If you’ve never witnessed a rut-crazed buck traveling across an open field at high noon, you haven’t put enough time in yet.

That kind of movement is the exception, but it can be exceptional. You probably won’t see a lot of deer during the middle of the day, but those you do see have a good chance of being worthy of your tag. If one or two get up and move at noon, they won’t show up on a biologist’s chart, but they might show up in the local big buck contest.

PRESSURE

A lot of savvy hunters pay close attention to the barometric pressure. The limited research that has been done on the topic shows little direct correlation between changes in barometric pressure and deer movement. However, those studies looked primarily at movement while the pressure was changing and did not take into account a lag effect — movement ahead of or behind a front. Most serious whitetail hunters will tell you deer move more in those lag times. Again, even assuming there is some validity to the barometric pressure theory, there isn’t enough extra movement to show up on the chart. But there are other kinds of pressure that affect deer movement.

Research shows an inverse relationship between daytime deer movement and hunting pressure. The more hunters you put in the woods, the less deer move during daylight hours. This is especially true for mature bucks. It would seem logical that the opposite would be the case, and to some extent it is. Yet again, that movement is still largely during twilight hours. However, increased pressure can sometimes have the opposite effect.

Public-land hunters often follow a predictable pattern. They enter the woods before daylight, settle in and await dawn. Some remain on stand, while others get up and still-hunt after daylight. As the morning wears on, the “standers” get cold, bored or hungry — sometimes all three. Most eventually start making their way back to the truck. As they do, they disturb resting deer.

The moving hunters might not see the deer, but those of us still on stand will.

How long this flurry of activity lasts depends on several things, including how many hunters are in the woods and when they leave. If the hunter exodus is protracted, so is the deer movement. It typically occurs around 10 or 11 a.m.

Some guys have a quick lunch and head back into the woods, but most wait for the afternoon hunt. We know that deer move best just before dark, but we want to get into our stands early enough to let the woods settle down before that occurs. With that in mind, we head in around 1:30 or 2 p.m. As we do, we again push deer toward anyone who might have decided to remain on stand. This creates an ideal scenario for the midday hunter.

Thus, after looking at the data and putting aside the specific examples mentioned earlier, I would have to say that science doesn’t really support the theory that midday hunting is best. Does that matter? Not as far as I’m concerned.

The vast majority of deer I’ve killed over the years were taken around dawn and dusk. Many of the biggest, however, came between 10 and 2. There are very few certainties when it comes to deer hunting. But one that consistently holds true is that you can’t kill a deer if you’re not in the woods.

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This article was published in the August 2010 edition of Buckmasters Whitetail Magazine. Subscribe today to have Buckmasters delivered to your home.

Copyright 2018 by Buckmasters, Ltd.

Copyright 2017 by Buckmasters, Ltd