Efficiency involves balancing the ratio of effort versus reward. Humans seek efficiency to save time, money, and effort. For white-tailed deer and all wildlife, it is a matter of survival. They have a nutritional deficit if they burn more energy locating food than they gain from eating it. The only way to stay on the positive side of the energy cost-benefit ratio is by choosing the most palatable and nutritious foods available. 

Contemporary research on deer diets tells us that deer prefer acorns over all other sources of regularly occurring hard mast. Even though those results come from peer-reviewed empirical science, they can still be somewhat misleading. Deer do indeed prefer acorns, but that preference is partly a result of abundance and availability. Another hard mast species once held the title of most preferred until it was gone. 

Before the chestnut blight in the early 1900s, American chestnuts (Castanea dentata) were the most prominent and dominant hard mast species in the woods, making up an estimated 25 percent of the eastern hardwood forest. Their nuts were also the most preferred by deer and other wildlife, not just because of their abundance but because of their nutritional quality. By selecting the most nutritious food, deer could maximize efficiency and improve survival rates. 

Chestnuts are a superior food source for several reasons. As autumn approaches, the deer’s diet shifts toward food higher in carbohydrates. Carbohydrates provide energy for the rut and allow deer to layer fat reserves they need to withstand winter. Chestnuts contain approximately 40% carbohydrates, compared to only about 10% for white oak acorns, so they have a more significant net gain when consumed. Furthermore, mature chestnut trees can produce more carbohydrates per acre than oaks and cornfields, so deer gain an even more significant net gain by not traveling as far to find food. This nutritional superiority of chestnuts is a fascinating aspect of wildlife habitat management. 

Though growth slows in fall, deer still need certain levels of protein, vitamins, and trace minerals to maintain proper body function. Chestnuts contain 10% protein compared to only 4% for white oak acorns. They also contain more vitamins C, E, and K and are higher in iron, potassium, and selenium than acorns. While the former two are often abundant in the environment, selenium is sometimes scarce, yet it is essential for immune function, reproduction, and overall health. 

White-tailed deer are selective feeders seeking the most nutritious and energy-efficient food. Though chestnuts have been largely absent from the landscape for several centuries, deer still strongly prefer chestnuts when they can find them. Dr. James Kroll found this to be true. In studies of captive deer, Dr. Kroll found deer preferred chestnuts to acorns at a rate of 100 to 1. In addition to being more nutritious, chestnuts are more palatable because they lack tannins that give acorns their bitter taste, but the advantages do not stop there.

Chestnuts are also advantageous for those who plant mast trees to improve wildlife habitat. Chestnut trees grow faster and bigger than oaks. Under optimum conditions, they may begin bearing nuts within two to five years, whereas a white oak might not bear for twenty years. Chestnut trees can grow 60-80 feet tall, and at maturity, Dunstan Chestnut trees can produce up to 2,000 pounds of nuts per acre. 

Chestnut trees have several growth characteristics that make them more efficient at production. They flower later in spring than oaks, reducing the possibility of damage from late frosts that could cause widespread acorn failures and starvation years for deer. 

They also have a very different cyclical nature than oaks. Under favorable conditions, they will produce a bountiful crop every year. Even under the poorest conditions, chestnuts typically produce some nuts, which can quickly rebound to produce a bumper crop by the following year. Red oak acorns take two years to mature and drop, and one poor growth year could translate to at least three years of poor production. White oaks can produce acorns yearly, like chestnuts, but only if conditions are optimal. Unlike chestnuts, they often alternate between years of good and bad and sometimes no production, producing bumper crops only every four years, on average. 

In short, chestnuts are a more efficient and reliable option. They provide a nutritionally superior food source for deer so that the deer can maximize efficiency. The trees themselves are more efficient and effective at producing superior nutrition. Landowners can maximize efficiency by planting the best producers: chestnuts.