LET BUCKS GROW UP
So, deer are not cows. They have different breeding systems, different habitat needs and different nutritional requirements. For far too long, deer hunters have placed heavy pressure on the buck segment while under-harvesting does. The result is an extremely young buck herd and a very old doe herd. I’ve found it productive to point out that no rancher in his right mind would sell only the best bulls and keep the worst, year after year. The result would be a very poor herd of cattle! Yet, that is exactly what deer hunters often do by over-harvesting older bucks.

Back in the early ‘90s, the Georgia Department of Natural Resources, along with significant financial support from North American Whitetail, managed to convince hunters and landowners in Dooly County, Georgia, to place size limits on bucks. This was a landmark experiment. It actually became a Master of Science research project for University of Georgia graduate student Micah Goldstein, and it worked from the ground up with both landowners and hunters. In a short time, the project garnered significant public support. The project was a success, and now several other states have implemented similar size restrictions.

“LEAVE THE OLD DOES TO BREED”
Both laymen and some wildlife biologists subscribe to this incorrect doctrine. In Michigan, for example, it’s a commonly held belief. Sadly, many of our deer herds are in such poor shape that results of research lead some professional biologists to entirely incorrect conclusions. These deer herds have had such poor quality for so many years that some biologists have started to think the abnormal is normal!

For several years now, I’ve been conducting research on the productivity of certain Michigan herds. We do this by collecting fetuses from harvested does and aging them. Long ago, scientists in South Carolina and other locations found a remarkably predictable relationship between the crown-to-rump length of deer fetuses and their age. By simply taking this measurement from the fetuses, we can estimate conception date.

Likewise, the average number of fetuses per doe is a valuable indicator of the productive capacity and health of the herd. At first, our data showed the same thing being reported by other Midwest scientists: Older does were prone to have more fetuses than younger does. But there’s a lot more to the story.

Another aspect of my research involved reducing the herd to a level below carrying capacity, as well as increasing the nutritional plane of the deer through habitat manipulation and food plots. After this was done, we started seeing a much higher incidence of younger does becoming more productive. There is no reason that the average number of fawns produced by younger does will not equal that of older individuals, but the reason for the misconception is clear. Indeed, at high population densities, it takes a doe longer to reproduce successfully.

At maturity (4.5 years old or older), a doe tends to gain dominance over the other individuals in her matriarchic group. Being the “top dog,” she then has access to the best fawning sites and best foods. However, once you remove the sociological and biological stress factors, even the younger does are successful, and younger does tend to produce the best offspring.

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