deer breeding in febFor many years biologists and hunters believed that most adult does were bred by bucks 3.5 years and older, a theory I always questioned. In many areas of the U.S., deer herds are overloaded with does, and there are relatively mature bucks 4.5 years and older.

So in peak rut, when many does come into estrus at one time, which bucks are actually doing the breeding?

According to research published in the Journal of Mammalogy, immature bucks (1.5 and 2.5 years of age) are breeding does at a much higher rate than once thought. In one study, researchers analyzed the DNA samples of more than 1,200 whitetails in 3 different populations (Mississippi, Texas and Oklahoma) and found that young bucks sired 30 to 33% of the fawns.

This seems to prove my personal and totally unscientific theory, but one I think makes a lot of common sense: On public and private lands that are not managed and which do not have a large population of 3.5 to 5.5 year old bucks, the 1.5 and 2.5 year olds MUST be doing a lot of breeding. I’d bet it’s more than 33 percent in some areas.

But here’s an interesting finding. The DNA researchers found that even in a population with a good number of mature bucks, immature males still sired 30% or so of the fawns. So in layman’s terms, the old boys don’t suppress the randy youngsters with big rubs, snort-wheezing and their mere big-racked presence as much as we once thought.

Upon analyzing these studies, one whitetail biologist said, “This genetic research crushes our thinking on how whitetails do their breeding. What amazes me most is that we really believed for the longest time that there were a few dominant bucks that did most of the breeding.”

Cool stuff. I feel sort of vindicated.