October 28, 2010
By Bob Humphrey
By Bob Humphrey
There's an expression biologists use: "negative data are still data."
Essentially, it means that just because you don't get the results you expected, it doesn't mean you didn't learn something. For example, if we conduct the same experiment and get the same result, it wasn't necessarily a waste of time, because it confirms what we thought we knew to be true.
Wildlife biologists are forever trying to unlock the mysteries of whitetail deer. We're constantly pushing the envelope, but we also go back and check on conventional wisdom from time to time -- especially as new technology becomes available. For biologists and hunters alike (the two are not mutually exclusive), one area of great interest is factors influencing deer movement. Knowing what makes deer move could potentially give us an edge. And if we can predict deer movement, or at least when optimal conditions for deer movement will occur, then we also know when we should be in the woods.
Recently, at the 32nd annual meeting of the Southeast Deer Study Group, Stephen Webb presented a research paper on such an effort. He and co-authors Bronson Strickland, Kenneth Gee, Stephen Demarais and Randy DeYoung looked at what effects reproductive phase, moon phase and short-term weather patterns have on deer movements.
Similar research has been done numerous times before. However, previous research used radio collars, which may have provided one or two short observations per day. Webb's study used GPS tracking collars that transmitted deer locations every 15 minutes. Very few studies had ever documented movements on such a detailed level. One would expect the results to be much more accurate, though not necessarily different from what was previously found.
Bucks moved more during the rut. Nothing earth shattering there. It's what experience tells us and previous research has confirmed. Still, isn't it comforting to know it holds true, even under the scrutiny of the latest technological advancements? If bucks move more, they will be more susceptible to hunters. Now, if we could just hone that down a little to figure out when, during the rut, they might be more inclined to let their guard down.
Changes in weather (temperature, wind speed, pressure and relative humidity) had no statistically significant impact on deer movement during peak periods of dawn and dusk.
Weather-related variables only influenced movement during non-peak periods. In other words, the best time to be in the woods is early and late in the day. Again, pretty much what we knew. This one jibes with some, but not all previous studies. The differences are subtle, and hardly of the import of the third conclusion.
"Moon phase had no effect on daily, nocturnal and diurnal deer movements." I put that in quotes for a reason. I'm not paraphrasing or interpreting. That was as written in Webb's abstract. I guess it's just human nature, but we accept what we want to hear willingly, yet remain skeptical about the things we don't agree with. Webb's is the same result that keeps coming up in nearly all disciplined, scientific studies. Yet many deer hunters still refuse to accept it. Why?
Some if it may be wishful thinking. We so want the opposite to be true. And some may be due to what we observe -- or think we're observing -- without any real scientific control. Much, however, is the result of misinformation. Every so often, some pseudo-scientist comes along with a theory based on "results" from a non-scientific experiment (often largely anecdotal observation). They may have the best of intentions in trying to help their fellow hunters, though they're not. And because we hunters are so eager for answers, we're quick to accept the latest and greatest whitetail wisdom.
Meanwhile, biologists plod steadily along. Setting out to prove something we already know may seem a little frivolous at first. But wildlife biology is not an exact science. In fact, it's not a true science at all: it's a discipline. The inherent imperfections cry out for us to go back and take a second look, especially when we have new tools to do so. It's also important to bear in mind there are numerous uncontrollable variables, so results could differ significantly from one study area to the next.
To put it in bowhunting terms, whether you're shooting an old Bear Whitetail or a brand new Mathews Reezen, you would expect to make a 20-yard shot without much difficulty.
But I'll bet you're a whole lot more confident shooting the Mathews.