Book Review – Advanced White-Tailed Deer Management: The Nutrition-Population Density Sweet Spot

January 16, 2024 By: Lindsay Thomas Jr.

Managing a deer population is pretty simple, really. Improve habitat to increase the quality and quantity of deer forage, and reduce deer density if necessary until you achieve balance between forage supply and demand. Early on in a new book about deer management from Texas A&M University Press you realize this simple formula collapses in the dry fringes of the whitetail’s range, especially places like South Texas.

“Manipulating vegetation to increase forbs does not work if it does not rain,” the authors write, and that’s just the beginning of the accepted deer management rulebook you can toss out if you hunt and manage whitetails in the dry southwest. Reducing deer density increases plant diversity by taking pressure off the first-choice foods – but not here. “We found that rainfall had a larger influence than deer density on diet composition.”

As for antler growth, you must unlearn what you have learned. In fact, deer hunters have been taught that most aspects of a deer population – body weights, antler size, population growth, fawn survival, forage diversity and even cover quality – vary with deer density. In South Texas, these connections are weak or broken. Density takes a backseat to rainfall, and this has enormous implications for management.

Advanced White-tailed Deer Management is the story of a 15-year-long experiment conducted on the Faith and Comanche ranches by the students and staff of the Caeser Kleberg Wildlife Research Institute at Texas A&M University-Kingsville. Over those years, I listened as many of those students presented pieces of their findings at the annual Southeast Deer Study Group meeting, and I was a little confused. I kept hearing every year about the same array of 200-acre high-fence enclosures and the various experiments conducted on the deer living in them. I was skeptical we could learn a lot of practical information about wild deer from whitetails living in such confined spaces. Now that I’ve read this book, I understand. Each student was looking at a different aspect of a complex problem, and each study was building on those before it to reach the answer to a question none of them could tackle independently.

It is difficult to study the interplay of deer density, nutrition, antler growth, and herd health in free-ranging deer because of the difficulty of controlling deer density with precision. To fix this problem, researchers constructed two separate sets of six, 200-acre high-fence enclosures – one on the Faith Ranch and one on the Comanche Ranch. Deer density and supplemental feed levels can be customized in each enclosure, then the impact on the habitat and deer can be studied carefully. In fact, at times during the 15-year study, one of the six enclosures on each ranch contained zero deer, a way to provide a baseline of natural plant diversity without any deer browsing pressure at all.

This diagram in the book shows the 200-acre enclosures that were key to this study. Each enclosure held a different density of deer and feeders, allowing researchers to study the impact of various combinations on deer and habitat health.

Initially, at launch in 2003, researchers aimed to find the combination of deer density and supplemental feed levels that would produce the largest antlers on bucks without damaging natural vegetation – what they called the “sweet spot.” Later, the study goals shifted to push the limits of deer density and find out if even higher densities could be sustained with the use of supplemental feed without harm to antler quality or habitat.

Supplemental feed plays a starring role in this book because it has to be the partner of natural forage in this region if you want to increase deer numbers. It must be the stabilizer that fills the gaps in drought years, though natural forage is still important. “During wet years when vegetation peaked, antler and body measurements did too – even when supplemental feed was constantly available,” the authors wrote. They were also realistic about the costs: “Providing the amount of feed needed to maintain higher numbers of deer entails substantial costs in feeders, feed, infrastructure and labor.” 

Those costs rise with higher deer densities as deer eat more feed. In the second half of the study, the authors said they were spending over $100,000 per year on feed alone for a total study area of about 2,000 acres.

Another qualifier: the enclosures where the study took place exclude cattle, feral hogs, and most predators. If you hunt where deer share the woods with cattle that will be foraging on plants, feral hogs that will be competing with deer at feeders, or significant predator numbers that will be eating a lot of fawns, your results may be different. 

I also appreciated the authors’ caution about chronic wasting disease (CWD): “Feeding deer results in a concentration of animals and concerns about the spread of disease. CWD could cause a decline in South Texas deer populations because of the variable environment and frequent density-independent behavior of deer populations. We discourage feeding deer if this disease becomes established in the region.”

So, where did they find the “sweet spot?” I won’t spoil the ending for you. I’ll only say that you will thoroughly understand that ending when you arrive. Most chapters of the book open with a bullet-point “Highlights” list, like a syllabus of the concepts you will learn in what you are about to read. Each chapter ends with a sidebar summary titled “How New Concepts From Our Research Change Management.” With features like this, you can’t go astray, and you can always pull this book off your shelf and review the takeaways in a few minutes. The authors are meticulous about explaining the traditional concepts of deer management and contrasting them with their own findings. Numerous photos, graphs, charts and sidebars reinforce the messages. Though it’s the story of a scientific experiment written by biologists and professors, the book is far more user-friendly than a college textbook or scientific journal article.

If you hunt or manage whitetails in South Texas or other extremes of the whitetail’s range, you should read this book. I don’t hunt or manage South Texas whitetails and likely never will, but this book taught me that many widely applicable guidelines about deer management don’t work everywhere. It’s another reminder for me to be careful using absolutes like “always” or “never.” Whitetails are a highly adaptable species and have squeezed themselves into ecological niches where standard rules don’t apply. As the authors write, “Management is better informed by understanding the bigger picture of how things work.” 

Advanced White-Tailed Deer Management: The Nutrition-Population Density Sweet Spot, by Timothy Fulbright, Charles DeYoung, David Hewitt and Don Draeger is available from Texas A&M University Press for $35.00.

About Lindsay Thomas Jr.:

Lindsay Thomas Jr. is NDA's Chief Communications Officer. He has been a member of the staff since 2003. Prior to that, Lindsay was an editor at a Georgia hunting and fishing news magazine for nine years. Throughout his career as an editor, he has written and published numerous articles on deer management and hunting. He earned his journalism degree at the University of Georgia.