December 09, 2010
This annual gathering of deer fanatics is guaranteed to stir your whitetail brain cells.
By Dr. Dave Samuel
EVERY YEAR I REPRESENT Bowhunter Magazine at the Southeast Deer Study Group meeting, where the country's top deer researchers gather to share their latest findings. It's always a great place to learn more about whitetails, and this year was no exception. The folks at Texas Parks and Wildlife hosted the 2010 meeting, and they did not disappoint. So grab your cowboy boots, saddle up, and hang on as we again race through the latest in deer biology, management, and behavior.
How Far Can Deer Management Go?
Most of Texas manages deer the same way the rest of the country does. However, in South Texas, management differs a bit, and the Texas Parks and Wildlife Department has given ranchers there the tools to grow more and bigger bucks. Here is an example: Hundreds of fenced ranches build breeder pens as large as 100 acres. Using a Deer Management Permit (DMP) from the state, ranchers can capture up to 20 does and place them in a breeder pen with the biggest buck they can capture (or buy or rent from a deer farm). After the does are bred, the fawns and does are released back onto the ranch proper. Thus, year after year, does are getting bred by huge bucks, and their male progeny will most likely have improved antlers. Since almost all deer hunting in Texas is on leased ranches, bigger bucks mean bigger bucks ($).
However, former Texas wildlife professor Bob Brown presented a paper asking how far modern deer management can go, with questions such as: "Is the use of supplemental feed, deer management permits, culling, etc. really taking steps toward domesticating deer?" Dr. Brown suggested that domestication may be leading to private ownership of deer, and that is a concern for many.
Smile For The Camera
Do you hunt on a small area and want to know the ratio of does to bucks on the property? Researchers at Texas Parks and Wildlife determined that sitting in a blind near a bait pile in the mornings was the most accurate way to gauge sex ratios. They also learned that for smaller, closed populations, cameras over bait for seven days photographed 98 percent of all bucks.
Auburn University researchers evaluated cameras in assessing deer populations. They placed cameras at random locations along game trails and at bait sites to determine if they could quantify the sex and age structure in a population. They assumed (rightly so) that cameras placed randomly would have the least bias. One question about bait site data is, "Do all deer use bait equally?" If not, then counts taken there would be biased. Results showed that doe counts were about the same at random cameras sites, sites along deer trails, and at baited sites. For mature bucks during the prerut, counts were low at random camera sites but not at camera sites on trails. Camera counts at baited sites were lower in the prerut and the rut. The researchers concluded that the best way to assess an overall deer population is to place cameras at baited sites before and after the rut.
Does Supplemental Feed Improve Antlers?
More and more private hunting and lease clubs are using supplemental feed, raising the question: What percentage of bucks and does in various age classes eat supplemental feed when available? A study at Comanche Ranch in South Texas analyzed food consumption in pastures with supplemental feed and found that 69 percent of yearling does and 92 percent of does 2½ years old and older ate supplemental feed. In fact, supplemental feed made up 48 percent of the diets of older does. Sixty-one percent of older bucks consumed supplemental feed. Also, the higher the deer density, the higher the percentage of pelleted feed in the deers' diets.
Now, to the critical question about the impacts of deer densities and supplemental feed in relation to antler size: Researchers at the Caesar Kleberg Wildlife Research Institute looked at deer in 200-acre enclosures on the Faith Ranch and Comanche Ranch in South Texas. Half the pens had supplemental feed, half had none. Some pens held 10 deer, others 25, and still others 40. Here are the results: In pens with no supplemental feed, 95 percent of yearlings were spikes; in pens with supplemental feed, 41 percent were spikes. Density did not affect these numbers. Gross Boone and Crockett scores for bucks over 5½ years of age in the "no feed" pens dropped 1.2 inches for each additional deer in the pens. Gross Boone and Crockett antler score for bucks over 5½ years of age on supplemental feed was not affected by deer density. Bucks over 5½ years of age scored an average of 116 inches with no supplemental feed, while those on feed scored 131. In summary, on those South Texas ranches, supplemental feed reduced the number of yearling spikes and increased antler score for older bucks.
Aging On The Hoof
For years, biologists have known how to age deer based on tooth characteristics, but in recent years, aging deer based on body characteristics has become the rage. In theory it sounds great, but is it accurate? Based on a study by the Samuel Roberts Noble Foundation, it is not. Those conducting the study showed 14 very experienced deer biologists photos (nine photos of each buck) of known-age bucks and asked them to estimate the age of each buck. Here are the ages of the bucks and the percentage of correct answers from these "experts:" 1½ years old -- 69 percent, 2½ -- 44 percent, 3½ -- 27 percent, 4½ -- 31 percent, 5½ -- 21 percent, 6½ -- 12 percent, 7½+ -- 53 percent. Those scores look pretty bad, considering that trained biologists guessed wrong on 31 percent of yearlings. They estimated those bucks at 2½ years of age. And they estimated 50 percent of 2½-year-old bucks as 3½ years old or older. Not good.
How about a method that will score deer in photos? Now here is something that works. Jeremy Flinn from Mississippi State University has devised a computer program that can score bucks in trail cam photos. You send Flinn a photo in which a buck is facing, quartering toward, or at right angles to the camera, and Flinn's computer program will score the buck within 4.5 percent of the actual score. Just go to www.buckscore.com to get your buck photos scored. What will they think of next?
As always, the Southeast Deer Study Group meeting stirs the whitetail brain cells, so you can be sure that next February, Bowhunter Magazine will be in Oklahoma City for the 2011 meeting. It's open to anyone, so I hope to see you there.