Research keys on white-tail basics

By JULIET BRISKIN | Staff writer

People attending the Kerr WMA White-tail Deer Symposium listen to Bill Armstrong (right, back to camera) detail facts about deer management. Following Armstrong's talk, the group was led on a field tour where deer (such as the buck pictured below) are pastured. -- Staff photos by Briskin

September 25, 2003 -- There are two basic facts about white-tailed deer that every land manager needs to know: they eat and they breed.

According to Bill Armstrong of the Texas Parks and Wildlife Department's Kerr Wildlife Management Area (WMA), if a land manager understands these two aspects of white-tailed deer, they are on their way to growing healthier herds.

During a white-tailed deer symposium at the Kerr WMA in Hunt on Sept. 5, Armstrong explained that the number one problem facing deer herds in the Hill Country is there are more animals on the range than food to feed them. "Each year in the Hill Country we will loose between 20 and 40 percent of our deer herd to malnutrition," stated Armstrong. "If the land is healthy, you have a much better chance of growing healthy white-tailed deer."

The Kerr WMA was purchased in 1950 by the Texas Parks and Wildlife Department to primarily study white-tailed deer. "One of the first things we did after purchasing the Kerr WMA was to build nine, 96-acre, deer-proof pastures on the north end of the Area and build one, 96-acre, deer-proof pasture in the center of the Area," said Armstrong.

White-tailed deer were placed in each of the pastures and studies were conducted with varying parameters. Some pastures were void of any white-tailed deer predators, some were stocked with sheep, goats, and cattle, certain pastures had more deer than others and in some pastures various types of vegetation were removed.

"Results of these studies showed that the more animals that were put in a pasture, the fewer deer we could grow," explained Armstrong. "In the fields stocked with cattle only, versus goats or sheep, we could grow more deer."

When studying the diet of the white-tailed deer, researchers discovered the deer preferred forbs or weeds. "We have learned that less than 10 percent of their diet is grass," said Armstrong. "For practical everyday management purposes, deer cannot eat and digest grass at a fast enough rate to satisfy their metabolism. A deer will die of malnutrition with a belly full of grass."

For many years, the Texas Parks and Wildlife Department had a no-burn policy, but the benefits of fire have since been discovered, and in 1979 a burn policy was put into effect at the Kerr WMA. "Every five years we come in and reburn a pasture," said Armstrong. "By burning we found a much more cost-effective way to clear a pasture, discovered that the burns released phosphorous the deer need in their diet, and the variety of vegetation we could grow increased." It was also demonstrated that deer and cattle raised on burned pastures out-performed those raised on land that never experienced a burn.

Along with the nutrition studies, on-going heritability studies are being conducted at the Kerr WMA. One of the first findings from these studies was antler traits and body weight are highly heritable. Armstrong explained that there are basically three types of deer in a pasture; antler producers, spike producers and swing deer.

Today, most land managers and hunters are looking for the antler producers. The key to creating herds with the desired genetics is to concentrate the gene pool of the sire, according to Armstrong. "Theoretically 25 percent of a sire's offspring are going to get the better characteristics, 25 percent will get the lesser characteristics and 50 percent will fall somewhere in the middle."

While genetics play a substantial roll in herd success, Armstrong is emphatic about the need for good nutrition and keeping the land healthy. "I want everyone to know that I am talking about a lot more that just

white-tailed deer," he explained. "I'm talking about ... how to make the land healthy, and in turn, grow healthy white-tailed deer."

For more information on white-tailed deer symposiums visit www.tpwd.state.tx.us/wma. For more information on the studies conducted at the Kerr WMA contact Bill Armstrong at 830-238-4483.