Field & Stream – October 2009

Rut Myths Debunked

By: Scott Bestful

ONGOING RESEARCH HEADED by Texas A & M University on the state’s legendary King Ranch is kicking some widely held beliefs about the breeding behavior of bucks to the trailside. 

The study, which began in 2000, is designed to assess the percentage of fawns sired by dominant bucks on the 825,000-acre ranch.  Using DNA sampling techniques to match captured bucks and the fawns they sired, biologists were able to trace the paternity (as well as estimated conception dates) of 70 litters of fawns.  The results so far appear to refute several common myths about rutting whitetails.  They may even cause you to alter your hunting tactics this season.

Myth 1  During the rut, monster bucks run willy-nilly across the landscape chasing does.  There is no way to pattern them.

            While this is true of some bucks, it doesn’t hold for all of them.  Yes, some bucks are ruled by their libidos now.  But not all.

            In fact, some truly monstrous bucks are complete no-shows during the rut.  “There’s a big variation in how actively even a mature buck participates in the rut,” says King Ranch biologist Mickey Hellickson.  “We had 7- and 8-year-old bucks that only bred hard for one season, and some bucks didn’t seem to get into breeding at all.  We don’s know if that’s dominance related, a personality thing {some giant whitetails are shy and reclusive}, or what.  But we’ve learned it’s impossible to predict the breeders.”

CONCLUSTION:  Some bucks will range widely looking for hot does, but many big ones (even those that participate in breeding) never leave their home range during the rut.  Killing these homebodies boils down to learning all you can about deer movement where you hunt.

Myth 2  Big bucks are vulnerable only during the peak of the rut.

One of the biggest surprises of the study was that immature bucks (1 ½ and 2 ½ -year-olds) sired 35 percent of the fawns-which blows away the notion that whitetail breeding is totally dominance-based.  Interestingly, mature bucks did monopolize does at some point of the season.  “Tracing conception dates showed that virtually all the fawns sired my immature bucks came from the absolute peak of the rut,”  Hellickson says.  “Conversely, fawns sired by mature bucks were conceived at a variety of dates before, during and beyond the rut peak.” 

“We believe this means mature bucks keep breeding longer than younger deer.  This matches up to a rattling study I did several years back; the weeks following peak rut were the best times to rattle in a big buck.  Immature deer just didn’t respond.  In fact, we see them re-forming bachelor groups within three weeks of the peak rut.”

CONCLUSION:  When the peak of the rut has passed and you haven’t tagged a big one, don’t despair.  If anything, big bucks will be more vulnerable in the days and weeks to come.

Myth 3  Preserving mature bucks will allow them to bread more does and improve the overall genetics of the local deer herd.

            This is highly improbable, according to Hellickson, “It’s true that mature bucks in the study did the majority of breeding, but remember that the King Ranch is intensively managed.  Up to 30 percent of the bucks here are at least 5 ½ years old, and we shoot bunches of does.  Even then, immature bucks did plenty of breeding.  Most wild populations will have fewer mature bucks and be less balanced.”  Hellickson also notes that even the most mature, aggressive breeder can tend only a handful of does each fall.

CONCLUSION:  If you have the luxury of managing property and want to see a certain buck reach another age class, then don’t shoot him.  Just understand that in all likelihood the genetics of the herd won’t be affected one way or the other by your decision.