For years, hunters have been told to maintain their deer population at carrying capacity. The reason most often given was so that the natural food source could sustain the herd.
Now a long-term Texas Parks and Wildlife Department study may provide even better reasons — bigger antlers, larger deer and stronger fawn crops while saving money.
“It is simple to go to a population with feed or a feed bucket and make them good or better. We wanted to see how they would respond to their environment without (supplemental) feed,” explained Ryan Reitz, manager of the Kerr Wildlife Management Area and one of the biologists involved in the research.
The study is looking at the role energy in a food source plays on deer quality with the goal of not creating a better commercial feed or feeding method, but using what is naturally on the ground.
Typically when talking about deer feed, the conversation revolves around protein levels, carbs and fat. Seldom is energy factored in.
“We are not saying protein isn’t important. It absolutely is, but what about energy,” Reitz said.
Energy is determined by looking at the calories in a food source and how many of those are digestible, organic matter. In Texas, Reitz said, some of the highest quality energy is mast such as acorns, seeds and fruit, but a lot also comes from forbs and weeding plants followed by browse plants.
The study looked at more than just the impact of what deer eats. It is also looking at the decline of quality over generations because of the lack of quality food sources, and whether it can be reversed.
“Deer being a product of their environment, there are environmental cues passed from generation to generation,” Reitz said.
The study done on the Kerr Area used two herds on feed, one that had an energy level of 2.8 kilocalories per gram considered good or adequate for a deer to be healthy. The other was lower energy level of 2.2 kilocalories per gram or about as low as a deer can healthily survive on.
Reitz said the idea was to see how the differences impacted body and antler size immediately and from generation to generation, as well as its impact on fawning.
Some of the differences were staggering. Deer on the high energy feed showed a mean difference of antler growth of about 24 inches. They also weighed about 20 pounds more and their body size, length and height were also larger.
What was a little surprising is that although the does on the lesser feed were smaller bodied, researchers did not see differences in fawning.
“We put females in a breeding situation, and they reproduced. The ones on the low energy would have as many twins and as many babies. They were trading off body size for reproduction,” Reitz said.
He added that while some findings are surprising, the early research does provide a blueprint for deer management.
“There are things we wouldn’t have predicted completely. This gives landowners a chance to go back to their management practices and plans and see what they are doing over a long period of time,” Reitz said.
He added the findings do show the need for land management to keep high energy plants growing.
“For growth and regrowth, there are ways to overcome and improve like prescribed fire, grazing systems and short duration grazing. Keep the landscape in good growing and recovery condition,” Reitz said.
The key is to find out what systems and techniques work best in each region of the state since Texas’ geography differs so much. And of course, the big variable that cannot be manipulated is rainfall.
“Soil and rainfall, that is 80% of the equation. Some regions just don’t have the plant base. They have limitations because of soil and rainfall,” Reitz said.
While this study did not look at energy’s impact on spike bucks, the last phase of the study is determining if a herd can overcome an early shortage of energy in their diet to revert to higher quality animals, and if they can how many generations does it take.
There is a massive change underway in the state with ranches and farmland being gobbled up for recreational purposes. In many instances, the new landowners see the initial deer quality and want to improve it quickly by bringing in farm-raised deer. However, if TPWD proves correct in the next phase, those landowners already have the genetics for quality deer. Maybe not the freakish 200-plus and larger deer, but native deer that are more than representative of their region.
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