Buckmasters Magazine

Does Age Matter?

Does Age Matter?

By Bob Humphrey

Through dense fog that had waxed and waned all morning, I noticed what at first was just a vague shape. I could tell by the way it moved he was a buck, probably an older one. He walked along slowly, deliberately, as with an objective that would come at a time and place of his choosing.

First, the fog gradually revealed a square body, then a tall rack. It was hardly spectacular: eight points, inside the ears and brow tines of only a couple inches. But it was revealing. The rack carried heavy mass well out the length of both beams, and the right P2 was bladed.

Then I noticed other features. For an obviously older deer during peak rut, his neck was surprisingly thin, his muzzle long and gray. He was clearly over-mature.

A lot of folks, especially on a guided hunt in Buffalo County, Wis., would have passed the deer in hopes of something bigger. But I’ve reached the age and the stage in my hunting life where my definition of a trophy is defined more by the circumstances, and as much by the deer’s age as some objective measure of its antlers.

In my mind, any mature buck taken under fair chase conditions is a trophy. That alone is a legitimate, albeit somewhat selfish, reason to want more older deer around.

But in addition to providing greater satisfaction from the hunt, there are also compelling biological reasons for having more older deer.

Dashing vs. Debonair

One of the most insightful experiences I ever had came on a Saskatchewan deer hunt during peak rut. Periodically throughout the first two days, does would assemble around a bait pile roughly 100 yards from my stand. It seemed like no sooner had they settled in to feed when a young buck would come along and scatter the group as it chased a potentially hot doe willy-nilly through the forest. Seeing only young bucks was frustrating enough, but to have them continually chasing off my buck bait was even more aggravating.

About mid-morning on the third day, at about the same time a group of does did, I noticed a deer moving slowly through the timber. Just like every other time, they threw up their heads and stared, some nervously stomping their feet. But instead of rushing headlong into the does, this buck held its ground, waiting until the does resumed feeding before inching closer, then pausing again when they perked up.

Even when the buck finally broke cover at 75 yards and it appeared the does were now comfortable with his presence, he didn’t dash in. Instead, he approached slowly and steadily. I can only assume he would have been more gentlemanly about escorting one of the ladies away, but I never gave him the chance.

That experience was insightful because it demonstrated the behavioral differences between young and old bucks. Like adolescents at their first high school dance, yearling bucks are impulsive and awkward when it comes to breeding. They also expend more energy, which they might need later for winter survival. Their clumsiness could also cause does to expend more energy. But that’s just the tip of the age-structure pyramid.

Triggers

We usually think of the first does coming into estrus as being the primary trigger for the rut. What makes that happen? In general, it is gradual changes in daylight that prompt physiological changes in the does’ chemistry. But there is evidence suggesting scrapes and rubs, which appear well before peak rut, might also play a subtle but important role.

One group of researchers suggested that primer pheromones deposited on rubs and in scrapes by dominant bucks could have a biostimulating effect, prompting adult does to enter estrus early.

It’s not a radical assumption, and other examples exist. We know, for instance, day length also influences the breeding season for birds, like turkeys. But the hen also needs to be courted. She needs to hear a tom gobble and see him strut. These behaviors trigger physiological responses that eventually make her receptive to breeding, and might even stimulate ovulation.

It’s also why frogs croak, elk bugle and woodcock do their sky dance. It very well might be why bucks make scrapes. After all, whitetails do most of their communicating through scent, not sound.

So what does this have to do with age?

A couple things. As alluded to earlier, research suggests older bucks deposit the primer pheromones, and yearling bucks are not physically mature enough to produce them. Furthermore, more dominant bucks produce more pheromones than less dominant ones. Ipso facto, if more older bucks are present, the earlier and more synchronous the rut.

Why is that important?

To understand that requires a better comprehension of natural selection, or survival of the fittest. Rut timing and synchrony are influenced by several selective pressures. In northern herds, if fawns are born too early there might not be sufficient nutrition available. If they’re born too late, they will not have time to grow in size and stature sufficient to survive their first winter.

An abundance of research shows the latter case is more common in populations with skewed sex ratios and younger buck age structure, such as heavily hunted populations with no minimum age or antler score restrictions. 

Another selective pressure involves something called the saturation effect. A predator can only kill and eat a certain number of prey in a specified period. The more compact the rut, the more fawns are born at the same time, increasing the chances of survival for each individual. Were fawns born over a longer period, predators would have more time to pick off more individuals before the fawns reached an age where they are able to elude those predators.

There are always exceptions, as Mother Nature continually tests her boundaries. In years when there’s an early green-up, more early-born fawns survive, and more late-born fawns survive in years with mild winters. But over the long term — decades, centuries, eons — those born closest to the optimal dates have the greatest likelihood of surviving and passing on their genes with a disposition to do the same.

For the majority of that time, selective pressures worked on deer populations. Studies comparing pre-colonial deer populations with modern unhunted populations showed them to be quite similar, both having more balanced sex and age ratios than what we now observe in most hunted populations. In other words, white-tailed deer are genetically predisposed to be the most productive in populations with more evenly balanced sex and age structures.

Remedies

Clearly there are some distinct advantages to having more older bucks in the population. Making that happen, however, depends to a large extent on how much control you have over the deer population where you hunt.

One of the simplest and most obvious steps is to let them go so they can grow. Ease up, particularly on the yearling bucks. That’s easy if you own or lease sufficient acreage. If you don’t, consider approaching your neighbors about forming a cooperative. You might be pleasantly surprised to learn they share the same philosophy.

To this point we’ve discussed mostly yearling and mature bucks, but the two intervening age classes also are important. Yearlings and 2-year-olds can be as physically and behaviorally different as two different species.

Behaviorally, 2-year-olds have settled into a home range and core area instead of wandering recklessly about in unfamiliar territory. As a result of that and more experience, they’ve become much more proficient at avoiding humans, an ability that, like Scotch, only improves with age. And they already know how to behave around the ladies.

The jump can be significant physically, too. Where I live, yearling bucks typically dress out around 125 pounds and sport 4-point racks. Conversely, I’ve taken several 2-year-old deer that scored over 125 and dressed out over 170 pounds. That might be enough to satisfy some hunters, but it could be incentive for others. When hunters start seeing those kinds of results in just one year, they might be more willing to take the next step toward things like mandatory minimums and learning to age deer on the hoof.

Three years is where whitetails start to enter trophy status in many areas. In fact, some folks erroneously refer to 3-year-old bucks as mature. Although they’ve got one more year to reach that milestone, bucks are behaviorally similar to their older peers, if there are any.
In more heavily hunted populations 3-year-olds might be at or near the top of the age structure. In good habitat they sometimes carry record book racks.

If your goal is bona fide book bucks, 3-year-olds are the age class that needs the most protection. You’ll easily recognize yearlings and should be able to pick out 2-year-olds by antler and body characteristics. The 3s are the ones that will tempt you. They’re also the bucks that, given just one more year, should show a considerable increase in antler size.

Once bucks reach that year four milestone, in addition to providing you the thrill of a lifetime, they also keep younger bucks in check, help synchronize the rut and contribute to an overall healthier and more productive deer herd.

 

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