You were present in your maternal grandmother’s womb. I know this is a strange way to begin a story about deer, but stay with me: It’s the simplest way to explain an important concept of biology. Your mother – and the mother of every deer, too – was born with all the eggs she would ever produce in her lifetime. The egg that became you was in your mother’s body while it was still inside your grandmother’s womb. Thus, your grandmother’s health and quality of life influenced the way your body expresses your genetics.
What in the wide wonderful woods does this have to do with deer? It helps predict how soon we can expect to see bigger deer after balancing deer numbers with improved habitat. The Mississippi State University Deer Lab captured deer from the poorest habitat in Mississippi and put them on high-quality nutrition on par with the richest habitat. Captured in poverty, these deer literally woke up wealthy. They eventually grew to body and antler sizes only seen in the richest habitat – but it took two generations of deer to complete the transformation.
When external factors affect the expression of our DNA, it’s called epigenetics. I first heard of epigenetics when the MSU Deer Lab reported their study results, but more recently I saw Dr. Bonnie Goff of UCLA, a developmental psychologist, explain the part about our maternal grandmothers in a TikTok video. This helped it all make more sense to me.
Think of your DNA as the circuit-breaker box in your house. The breakers represent all the potential for electricity throughout the house, but you can turn some of them off. Epigenetics can turn on or off some of the genes in a deer’s DNA breaker box to enhance survival. Your efforts to improve a deer herd – through doe harvest and habitat improvement to balance deer density with nutrition – will have to wait for epigenetics to turn on some breakers, but how long?
The MSU Deer Lab Study
MSU Deer Lab captured pregnant does from the Lower Coastal Plain of Mississippi and moved them to their Deer Lab facility. The fawns born to these does, the first generation in the study, were weaned onto a high-quality diet of 20% protein. Eventually these deer bred with other deer also from the Lower Coastal Plain and produced the second generation, also fed a high-quality diet.
The Lower Coastal Plain features the least fertile soils and lowest quality habitat of any region in Mississippi. The Delta region is the highest quality. Bucks in the Lower Coastal Plain average 41 pounds smaller and 25 inches less in gross antler score than Delta bucks at 3½ years of age.
That first generation of these suddenly wealthy deer had mothers and grandmothers who lived their entire lives in Lower Coastal Plain habitat. Their DNA had the same potential for body and antler size as deer in better habitat, but epigenetic signals from their mothers and grandmothers cautioned them from growing too fast. Food that appeared in sudden abundance might not last, so you shouldn’t be in a hurry to explode in body size to your full genetic potential just because you fell on good times. If the food supply dwindled again, you’d have this giant body to support. This is very smart, actually, from a survival viewpoint – and it’s one of the reasons whitetails are the oldest existing deer species on Earth.
The fawns in the first generation of the MSU Deer Lab experiment didn’t blow up immediately into big deer. They gained a little size. Then, the second generation of fawns were a little bigger. With abundant nutrition having been sustained over two generations, the gamble of large body size faced much better of odds of winning.
So How Long?
Back to our question: How soon will you see bigger deer after improving nutrition? Your habitat and herd improvements will not pay off immediately. Don’t expect to see noticeably bigger bodies or antlers on deer the year after you balance deer density with nutrition. The improvements take time, especially if you are starting from a point of high deer density combined with low available nutrition, so you have to be patient and maintain your efforts. A doe starts her most productive and successful years of fawn rearing at age 2½, meaning she’s 3 when the first fawns of those years are born. In their study report, the MSU Deer Lab investigators wrote:
“Although individual deer will respond to increased nutrition in the short term, it will take five to 10 years of consistently improved nutrition for the ‘genetic switches’ to be turned on and stimulate greater expression of their genetic potential. Once turned on, you will see far greater improvements at the population level.”
But – and it’s an important but – your commitment to the effort cannot wax and wane throughout those years. The whole point of epigenetics for deer is to ensure good nutrition is reliable and sustainable before you commit the resources to your full genetic potential. If nutrition has good and bad years, epigenetic triggers are getting switched on and off and on again. That means even more years and generations will be necessary for noticeable change.
Also, epigenetic change is reversible. Deer body and antler size can shrink again if habitat quality is not maintained.
It Starts Today
To ensure stability, think diversity. Any single habitat-improvement technique can fail sometimes, but if you apply more than one, there are auxiliary systems. Plant food plots. Encourage and plant mast-producing trees. Promote natural forage through forest stand improvement. Use prescribed fire in a variety of seasons. Focus on spring and summer nutrition, when does are nursing fawns, as much as you focus on fall when you want to attract deer. In concert with this habitat improvement, maintain appropriate doe harvest to keep deer numbers in balance with the forage you produce.
“To produce the best-quality deer, you must provide them with the opportunity to forage on the best-quality plants,” writes MSU Deer Lab. “Maintaining appropriate deer density, practicing active habitat management, and planting supplemental forages are tried and true methods of improving diet quality for deer. These actions will increase body and antler size of deer on a property.”
To learn much more about the MSU Deer Lab study, read their publication, The Role of Genetics and Nutrition in Deer Management.
