Buck Science Part II
Scientists read deer brain waves to find out what whitetails do and how they do it. Their research can help you figure out what bucks will do before they know.
September 22, 2009
Biologists in Michigan, Minnesota and other northern states have found that 5- to 40-acre conifer swamps, with trees 10 to 25 feet tall and canopies 50 to 70 percent closed, provide the best thermal cover for deer.
What it means: In the late-season, look for pines of that size; hunt on a nearby trail on the down-wind side to punch your tag late in the season. Also, look for bedding areas that are sheltered from the wind on very cold days. Deer often like to bed on east- or south-facing slopes in the winter so they can block the prevalent wind and bask in what sun there is.
Look for Winter Feed
Pennsylvania ruminant nutrition specialist Phil Anderson rhetorically asked, "Did you ever kill a deer in December when the woods are dead brown, but the rumen contents of the deer's stomach is bright green?" He points out that deer love tender, green shoots all year-round and particularly in the winter; the animals sniff and dig around the woods and find them under the leaves.
What it means: Be on the lookout for spots where deer have dug and pawed the leaves (deer sign is narrower and more linear than wild turkey scratching). Get down on hands and knees and investigate. If you find green shoots, set up there and fill your last doe or buck tag.
Let Them Grow
Speaking to rack growth and antler regulations that some states have implemented or might in the future, Mississippi State researchers Bronson Strickland and Steve Demarias wrote: "A yearling buck will grow antlers that are only 25 to 30 percent of his maximum B&C score. One of the surest ways to double the size of antlers is to let bucks grow to two years of age (antlers will be 60 percent of their score)."
What it means: If you are into management and want to see more big racks on your land, let them live longer. The researchers point out that a three-year-old buck will have put on 75 to 80 percent of its rack score; a four-year-old titan will be at 95 percent, take him for sure if you can.
How Well Deer Hear
Dr. Gino D'Angelo and researchers at the University of Georgia put does and bucks in a sound chamber and monitored their brainwaves to see how the animals responded to different sounds and frequencies. They found that deer hear best at moderate frequencies of 3,000 to 8,000 hertz, which is similar to humans.
What it means: Unless you tromp through the woods like an elephant, you won't spook many deer. Minimizing your movement and scent are more important.
How the Barometer Relates to Deer Movement
Years ago, Illinois biologist Keith Thomas found that whitetails moved and fed the most when the barometer was between 29.8 and 30.29 inches. Researchers have also found that deer are more active when the barometer is moving rather than steady.
What it means: Stay on stand all day when the pressure is in that range, especially in the rut.
When to Hunt a Waterhole
In a study at the Kleberg Wildlife Research Institute in Texas, scientist David Hewitt and others found that whitetails most often visited a permanent water source (pond, stock tank) about three weeks after the last measurable rain.
What it means: Most days, deer get their water need from green foods or by sipping at temporary sources (rainwater pools in ranch roads or dry creek beds, for example). But when it's hot and dry and hasn't rained for three or four weeks, hunt near a permanent water source where a lot of deer will come from all over to drink.
What Deer See
In a study funded by the Georgia Department of Transportation in hopes of reducing deer-car crashes, Dr. Karl Miller and others focused on the whitetail's vision. They confirmed that to get a good 3-D look at a strange object, a deer has to shift its head and stare at it from several different angles. Additionally, they said a deer's eyes are well adapted to detect movement.
What it means: When a doe or buck looks your way and starts head bobbing, freeze. When the animal dips its head and appears to look away, stay frozen. Only when the head-bobbing stops for good and the deer relaxes and seems satisfied that you are not dangerous should you shift in your stand or draw your bow.
D-I-Y Acorn Survey
Matt Tarr, biologist and forester for the University of New Hampshire, tells how to do an acorn survey in your hunting woods in mid-August. Go to the big oaks, glass the treetops, and estimate the average number of green acorns within 24 inches of each branch tip. Jot down the numbers and check other trees on a ridge or in a bottom. Go home and work the figures.
What it means: Tarr says that a white oak with an average of 12 to 18 or more acorns per branch is a good to excellent producer; with a red oak tree, that number rises to 16 to 24 plus. Hone in on those prime oaks and hang your stands now for super bowhunting in a month or two.