I had the opportunity to spend a weekend in February in 2013 at Turtle Lake Club in Hillman, Michigan. I was there volunteering and learning from Dr James Kroll and Wayne Sitton. They were conducting their annual Necropsy and Winter Herd Health check. An ongoing study they have been conducting in cooperation with the MDNR. I am going to dive into what I learned there, and the discussion is going to mainly talk on different aspects of the Rut, breeding, and peak buck movement.
Let's start with facts:
1. There are 3 phases of the rut: Pre rut, Rut or Breeding Rut, Post Rut. 2. They are all defined with certain characteristics that are distinct in nature and separate them from one another. 3. They occur every year in about the same times, give or take a few days, it's like clock work and has very little deviation due to weather, moon, or the likewise. 4. The primary trigger of the rut, is the angle in which sunlight begins to strike a deer's retina causing a shift in hormones, causing changes and cue's in both sexes of deer.
Pre Rut is mainly composed of seeking and chasing, bucks are dogging does....but the does aren't in heat but coming close and some may have an early heat, especially if they were bred early and dropped her fawns early. You can see some pretty spectacular fights as testosterone really ramps up and bucks are edgy. Typically this begins to happen 3-4th week in October in Michigan.
Rut or breeding Rut, this is where the majority of breeding will take place and occurs primarily, depending on local herd dynamics first week of November thru the third week where it has tailed off. Lot's of hunters think its over, where really bucks are locked down with does breeding them in heavy cover away from competition. The majority of breeding occurs in a window as confirmed by measuring fetus post mortum and counting backwards on a known growth chart. In Michigan, some may agree or disagree....but that window usually falls in the neighborhood of Nov 5-10th, with alot of activity on both sides with some tending and breeding. Lots of guys see alot of bucks chasing and breeding does on opening day and day after, but alot of study shows a tremendous amount of breeding right prior to the opener of gun, but breeding does continue thru gun season.
Post Rut, this occurs after the primary or breeding rut is over. Happens in does that didn't get bred the first time around, usually 30 days. Time frame on this is Thanksgiving at the very earliest thru mid December. Interestingly enough, and especially in the SLP, where doe fawns drop early and have access to plenty of good groceries, when they reach about 80 lbs of body weight, they will get their first heat and they will most often be the primary breeders in the post rut. Last season on my lease, I watched a big mature buck breed 3 doe fawns in muzzle loader season, he was tied up with them in a thicket at 80 yards and I had no shot...so I watched and got a good look at the does, all very small and very typical body shapes of doe fawns.
Here are some pics from the 2013 Necropsy I was lucky enough to attend via a good friend of mine, where I really learned so much and set aside some old beliefs of mine. I got to meet the operator/manager of Turtle Lake- Wayne Sitton, and met many from the MDNR - Dr Steve Schmidtt as well as some out of state professional biologists...one of them none other than Dr James Kroll aka Dr Deer, whom I spent the day with picking his brain as well as Wayne Sitton. Over the years, many have been patient and took the time to teach me what they know and I am making this post to pay it forward. Special thanks to Tony Smith, Jim Brauker, Jake Ehlinger, Dan Timmons, Brad Robinson, and many more. This page should be a resource as well as a promotion to opening eyes to the many benefits to advancing and protecting young bucks. Let them go and let them grow.
Now for some photos to show some of the learning process at my time at Turtle Lake.
Kidney specimens, they weigh the organ against the fat to determine the shape and general health..starving or doing ok in the winter months. Most doe had 3 lbs fat to 1 lb of kidney...and some as high as 5 -1...good indication of healthy non starving deer in Feb in the far north.
Fetus examination, sex and size. Size gives an incredibly accurate conception date, thereby defining exactly when the rut occurs and records show within a day or two every year.
DNR field biologist answering some questions about Bovine TB and plans and how things are going, she is explaining a litmus test that is a prelim for further lab analysis and it was experimental at that time.
We had a staton set up for removing jawbones and estimating age...the jaw bones ran thru 4 sets of trained hands, while learning and teaching were taking place.
Tony Smith, digging in and teaching and having some fun and putting in a long hard day volunteering at the Necropsy.
A sample of the does that were harvested for the study with DNR kill tags attached, the MDNR was on hand, biological division as well as enforcement. Not a single buck was killed mistakenly, much to the testimony of the skilled volunteer shooters......good glasses and verify....you can avoid making a mistake.
*Clarification from Jim Brauker*
Breeding during the primary rut occurs as a bell shaped curve starting towards the end of October, peaking in Michigan at around November 17th, plus or minus 3-4 days, and ending around the beginning of November. Peak breeding is not the same as peak of rutting activity. The most rutting activity starts during the period you mentioned Dean, from about the 5th to the 10th plus or minus a couple of days, but the peak of the rut happens later. The most buck activity is seen during that period because there are a substantial number of does coming into estrous but not too many. As the number of does in estrous increase towards the middle of the month, the amount of seeking activity among bucks goes down because there are more readily available females and they do not have to seek as far to find them. Another period occurs like that as the bell curve ramps down, but that activity is hugely disrupted in Michigan because of the gun season which results in reduction of the number of available bucks as well as the pressure induced movement of the does into lower pressure areas, heavy cover areas, or towards more nocturnal activity. The moon has nothing whatsoever to do with the timing of breeding. There are few things biologists agree on more than that. The timing of all this happens at different times in different states. This great study from New Brunswick shows you the bell shaped curve, as well as the lack of correspondence with moon phases. The only caveat is it occurs a few days later than the Michigan rut. Hope this helps.