A major study across two South Texas ranches found that years of removing male white-tailed deer with smaller-than-average antlers produced no lasting increase in antler size. The effort covered thousands of animals and spanned nearly two decades, yet average rack measurements in the treated areas stayed the same or declined once culling stopped. The findings contradict a long-standing recommendation that selective removal of smaller bucks would improve the genetics of future generations.
Why Managers Tried the Approach
Wildlife managers have long advised culling young bucks with modest antlers on the theory that it would reduce the number of small-racked males passing on those traits. Earlier work with deer held in pens appeared to support the idea, showing measurable gains in antler size that carried into later generations. Landowners managing private ranches for hunting therefore adopted the practice in hopes of producing more trophy animals over time.
The new research tested whether the same result would appear in free-ranging populations where deer could move more freely and where environmental conditions varied from year to year. Researchers worked on the King Ranch starting in 1999 and later expanded the work to the high-fenced Comanche Ranch. Both sites allowed direct comparison between areas where culling occurred and nearby control zones where it did not.
Results From the First Site
At King Ranch, managers and volunteer hunters removed 135 smaller-antlered bucks over several years while recreational hunting continued at normal levels. Annual captures and antler measurements showed no difference in average size between the treatment area and the control area. Tissue samples collected for paternity analysis also failed to reveal any inherited shift toward larger antlers.
The lack of effect prompted the team to design a stricter test at Comanche Ranch. There they applied two levels of culling, including one that removed 88 percent of the male deer in the intensive zone. Even with that level of removal, any short-term gains in antler size disappeared within a few years after culling ended.
Why the Expected Genetic Shift Did Not Appear
Several biological and environmental factors limited the impact of culling. Antler size varies widely from year to year because of rainfall and forage quality, so a buck that looks small one season may grow larger the next. In addition, white-tailed deer breeding involves many males rather than a few dominant ones, which reduces the chance that removing a handful of smaller bucks will change the overall gene pool.
Intense culling itself created complications. When most mature males were taken out, some fawns were born later in the season and entered winter in poorer condition, which may have further suppressed antler growth in the following generation. Experts noted that the opposite pattern seen in bighorn sheep, where heavy harvest of large-horned rams leads to smaller horns over time, does not reverse easily in deer because smaller-antlered males already have lower reproductive success.
What the Work Means for Future Management
The scale of the project, which included roughly 6,000 captures across both ranches, gives managers clear evidence that sustained culling of small-antlered bucks is unlikely to produce a genetically larger-racked population. Short-term improvements may occur on intensively managed properties, but those gains do not persist once the removals stop.
Researchers emphasized that the results apply most directly to open or semi-open populations typical of many working ranches. In fully closed, high-fenced settings the same limits on genetic change still appeared. The study therefore suggests that other approaches, such as improving nutrition and habitat, remain more reliable routes to better antler quality than selective harvest alone.
