For 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.
I’m with you Mike on the % being a bit higher than the 30-33%…
Around the Northeast where I hunt its probably much higher. I’ve seen a lot of 1.5 to 2.5 year olds breeding while I’m on stand. Guess you just hope these young bucks have good Mom and Pop genes to spread around…
Big Daddy, this begs the question from this not-so-young buck: Are you the “Old Bull” in question???? LOL!
Yes, Hanback, vindication is good. I would like to add that all bucks (old, young, and all others) only produce a certain amount of viable semen during the “Rut”. As a rule no buck is set up to breed a large number of does in any given breeding cycle. Unlike bull cattle whom produce plenty of semen throughout the cattle breeding season, stretched out over a longer period of time.
Interesting stuff, really. All the more reasons to love whitetails even more. They’re just such cool critters. They fascinate me for many different reasons.
Most the young studs around town breed most the young women too, but alas on the occasion an old bull gets to rub his horns all night long!