CULLING Bucks For Bigger Antlers: Yes or No?

Study #1: The Comanche Ranch Study

Donnie Draeger, a wildlife biologist at the Comanche Ranch, led a Scientific Study, along with co-researchers from the ranch, CKWRI and Mississippi State University. From 2006 to 2015, the scientists used helicopters to capture bucks on three separate treatment areas – a 3,500-acre “intensive” culling site, an 18,000-acre “moderate” culling site, and a 5,000-acre control with no culling. They captured 3,332 unique bucks and culled 1,296 of them.

7 Years Later

After seven years of culling, no evidence emerged of successful genetic improvement. I won’t repeat the details of the findings because you can read my original reporting on this study here. But keep this in mind as you read on: During the study, Donnie noted 10- to 15-inch jumps in average antler size across all three sites in years with good rainfall, emphasizing the effectiveness of habitat quality and nutrition in a study that showed culling was ineffective.

Study #2: The Faith Ranch Study

The first two studies used culling of existing bucks within the natural breeding ecology of wild whitetails. The third study dispensed with culling and used more artificial techniques to control who breeds who in an attempt to influence future antler quality. The methods used are legal practices in Texas that private landowners can conduct using Deer Management Program permits (DMP). According to Texas Parks & Wildlife, DMP “…authorizes owners of high-fenced properties to temporarily detain white-tailed deer in breeding pens located on the property for the purpose of natural breeding.”

In 2007, the Faith Ranch set up two, 1,100-acre, high-fence enclosures known as the West Yana Pasture and the East Yana Pasture. West Yana included two 5-acre DMP breeding pens within the larger enclosure. West Yana was emptied of deer, while local deer enclosed in East Yana were allowed to stay. Then, helicopters captured deer on a neighboring area, and they were stocked into West Yana’s 5-acre DMP pens.

In one West Yana DMP pen, they placed 15 does and a 176-inch (gross) buck. In the other, 15 does and a 223-inch non-typical buck. These two bucks were local champions – and the envy of whitetail bucks everywhere. They each did their duty with their 15 does in their 5-acre DMP enclosure, and all resulting fawns were captured, tagged, weighed, sexed and sampled for DNA. Then bucks, does and fawns were all released into the surrounding West Yana Pasture. The next year, two more large bucks were captured from outside and placed in the DMPs with a group of does caught within West Yana. This process repeated annually.

Improved nutrition in East Yana alone accomplished more for antler growth than intensive breeding control in West Yana.

Each year, fawns born in the DMPs were tagged and evaluated. Meanwhile, deer in West Yana were captured and evaluated, including fawns born outside the DMP pens. Bucks initially tagged as fawns were caught repeatedly over years and measured. Population density in West Yana was regulated through doe harvest, and the deer were supplementally fed.

If intensive culling of below-average bucks across thousands of acres for years  – didn’t produce measurable genetic change, surely high fences and breeding pens would. Right?

Fast forward to the arrival of Cole Anderson, who is currently working on his master’s degree at CKWRI. Starting in fall 2021, Cole began analyzing 15 years of DNA data from West Yana to build a family tree of fathers and sons, including antler measurements by age class.

MORE COMING…