T.R.'s Tips; Understanding the Whitetail Rut

[T.R. Michels]

This is from my Complete Whitetail Addict's Manual

The Rut
Most deer hunters know that whitetails act differently during the rut than they do at any other time of the year. After spending time with and talking to a number of different whitetail hunters, most of them experienced and some of them quite knowledgeable, I realized many of them did not understand the progression of the rut, or the time frame of the rut. Most of them knew that in the upper Midwest rubbing usually begins in September, scraping in mid-October, and that the “peak of the rut” occurs during the second week of November. But there seemed to be a difference of opinion about what the “peak of the rut” meant. To some it meant the time when they most often saw bucks during the day, usually the two weeks before the breeding phase. Others thought the peak of the rut meant peak breeding activity, which it does. Some thought all the breeding activity occurred during the week of the peak of the rut, and resigned themselves to the belief that once the peak of the rut was over no more breeding would occur. If they did not get a buck by the peak of the rut they believed there was no reason to hunt as hard, because there was less activity.

Rubbing, Scraping and Breeding Peaks
Rubbing, scraping and breeding all have their own time frames (which overlap each other), and their own peaks during the rut. Rut related activity in northern areas usually starts when bucks begin rubbing small trees and brush to remove velvet from their antlers and making scrapes. This may occur as early as late August or early September in area above the 38th parallel. Rubbing may peak in mid-September and generally diminishes throughout the rut, but it may rise again during later breeding phases. Scraping activity may begin as early as the first week of September, but without much activity until mid to late October. Breeding may begin in mid-October, and breeding begins to increase as scraping increases in late October. Scraping often peaks from mid to late October as bucks continue to make new scrapes and maintain existing scrapes. As breeding activity increases in early November scraping activity decreases. Breeding in northern areas may be intermittent from mid to late October; fairly continuous throughout November, with peak breeding occurring sometime between the first and the third week of November; and intermittent from early December into January. But, hold on what was that about breeding beginning in mid-October?

(This graph is on the "Rut Dates" page on my site.)

Data provided by the MN Department of Natural Resources

Note: The above graph shows the breeding dates of 1600+ does in Minnesota between 1980 and 1987. It clearly shows that that breeding of both yearling and older does begins in mid October and continues to mid January, for a breeding season length of 120 plus days. It shows that peak breeding during all years, and for all years combined, occurs during the second week of November. In addition, it shows that rarely do any more than 35 percent of the does in any one area get bred during the one-week time frame of the Peak of the Rut. It also shows that doe fawns in Minnesota breed from late October to early February; and that peak breeding of doe fawns occurs from late November to late December.

Estrus Cycles
Marchinton found that the estrus cycles of does ranged from 21 to 30 days, with an average of 26 days, and that does may recycle up to 7 times. My own observations, those of several other writers and photographers, and the studies of Dr. Larry Marchinton in Georgia show that breeding occurs as early as September 24 in northern Minnesota, October 15 in southern Minnesota, October 17 in Georgia, and October 24 in central Wisconsin.

     Thanks to Marchinton's studies we can actually pinpoint estrus cycles in captive deer. The study was conducted to find out how many estrus cycles unbred does would experience. During the study recurrent estrus ranged from 2 to 7 times. Of the eight does studied one 2.5 year old came into a first estrus on October 17, another on October 24, three 1.5 year olds on November 11, one 2.5 year old on November 19, one 1.5 year old on November 21, and one 5.5 year old on December 1. The last recurrent estrus occurred on April 7.

     This shows that, even without recurrent estrus, some does will be in estrus from mid-October to early December, resulting in a breeding period of more than 45 days. In northern areas the breeding period may last in excess of 60 days; from mid-October to late December. In southern areas it may last more than 90 days; into February. In most areas a small portion of the adult does may be bred in October, most of them in November, and a few more in December. This is typical of most deer populations. In northern areas 1.5 year old does may experience their first estrus in December. Doe fawns (5+ months) may experience their first estrus and breed in December, January or February.

Late Breeding Phase
As a result of Marchinton's study we know we cannot reliably predict when the late breeding phase may occur. Even if the majority of the does come into estrus at the same time, the research shows that recurrent estrus cycles are variable. Instead of occurring every 28 days as previously thought the cycles ranged from 21 to 30 days. This would make it difficult to pinpoint the late breeding period, especially when coupled with the knowledge that the first estrus of a doe may occur anytime from mid-October to mid-December. Another note of interest is that the does were in estrus from 24 to 48 hours, not the 22-24 hours previously thought. Any buck chasing a doe may spend up to three days with her without returning to its core area.

May God bless you and yours, and good hunting,

T.R.