Most biologists refer to bucks one-and-a-half to two-and-a-half as immature, three-and-a-half to four-and-a-half as mid-age, and five-and-a-half or older as mature. Accurately aging wild, free-ranging bucks on the hoof is impossible without identifiable markings that make individuals easily distinguishable. Even as such, it is still important to estimate the age of bucks in the field and via digital trail cameras.
Most consider a buck five-and-a-half or older to be mature, yet few hunters have actually seen a truly mature buck. This is because mature bucks are rare in many areas of our state. Some states produce more older-age bucks than others — namely states like Iowa, Kansas, and Illinois etc.
The factors that allow bucks to reach mature age classes include — but are not limited to — hunting regulations, individual management goals, land size, hunter density and local mentality.
Not having older-age bucks in an area can be detrimental to a deer herd. Abundant research shows skewed sex ratios combined with young buck age structures may result in does not being bred until their second or third cycles. Second and third-cycle fawns may hit the ground in July and August compared with does bred on time, which fawn late April through June.
Fawns born in July and August begin life at a distinct disadvantage. Hot, dry conditions reduce habitat quality by the time they’re born. They have less time to grow before the onset of winter, and predation rates are often higher because the “saturation effect” of having abundant prey on the ground at the same time is lost. Having mature bucks in the population helps ensure the majority of does are bred during their first cycle, bringing about the benefits of an earlier, shorter fawning period.