With the 30 inches of snow most of the Lehigh Valley received, wildlife have a tough time finding food. Deer and turkey especially have trouble finding suitable forage. As such, some well-meaning folks are putting out bagged corn or grain for both species. While commendable as it appears, their graciousness is only harming the species, deer in particular.
According to the Pennsylvania Game Commission, artificially feeding deer in the winter is the best way to kill a large number of deer in a small area in a short time. The problem, says the PGC, is that a deer’s diet cannot be rapidly changed in winter without damage to its digestive system.
“Deer, says the PGC, have a four compartment stomach that relies on microbes for digestion. The types of microbes change gradually in early winter to digest woody browse and again in spring to digest green vegetation.”
Illnesses such as acidosis and enterotoxemia often result when the winter diet is suddenly switched to simpler, more digestible carbs like corn or grain. Enterotoxemia occurs when these carbs cause bacteria to bloom in the deer’s digestive system. This bacteria is beneficial during normal feeding events, but too much releases a neutrotoxin that is absorbed into the blood, which results in death, as, explained in a PGC booklet.
In his book “The Deer of North America,” my friend and acclaimed wildlife photographer Leonard Lee Rue III writes that as far as mortality in winter, deer yard-up in dense evergreen swamps, draws, gulley’s or along brushy watercourses. And although wind and cold cause deer to yard up, it’s snow depth that determines how long they remain yarded. However, whitetails are not herd animals, but merely gather into large groups when forced to. When you see loads of trails and hoof prints in an area, it means deer are searching for food. You can see this by the myriad of trails around a small island of trees on farmland off Mauch Chunk Road and across from Fellowship Manor nursing home in Whitehall.
In his studies of deer, Rue found that deer can paw grasses in 6-8 inches of snow for forage and has seen some deer go as deep as 16-18 inches. But with 30 inches, that depth makes it impossible to find food.
In his book Rue said although deer feed on grasses, they much prefer broadleaf forbs (nongrass herbaceous plants), even after forbs have died and dried. He has seen deer stripping dried leaves off dried stalks.
But in cold wintry weather, their main objective is to get out of the wind and under trees where snow depth is usually less and half the snow is held aloft by the branches. And when the snow melts, the area under the trees will be bare long before the surrounding area is free of snow. These areas, writes Rue, is always warmer because it also traps whatever warmth the sun gives. And the branches provide a protective umbrella
The PGC points to studies that have shown that deer can die from feeding on highly digestible, high energy, low fiber feed such as corn in winter. This rapid exposure to a concentrated grain diet can cause a fatal disruption of the animal’s acid base balance. Deer that survive the immediate effects of “grain overload,” often die in the days or weeks that follow, due to secondary complications of the disease. And young deer are more susceptible since they are the last ones to feed after the larger, older, stronger deer eat first.
Another point the PGC makes is that supplemental feeding sometimes congregates deer in unnatural densities. Luring large numbers of deer in a small area could create a risk for spreading CWD, tuberculosis and in turkeys that feed on “deer corn.”
The photo accompanying this column shows how deer have eaten the ivy within their reach from this front yard tree. They’ve also dined on azaleas within the same Northampton County yard.
The PGC concludes that supplemental deer feeding during hard winter months increases the winter death rate by 25-42 percent. They recommend planting certain trees, bushes and maintaining autumn food plots instead. That, and felling firewood trees in late winter puts deciduous treetops where deer can reach them.
Rue found that deer prefer smaller twigs on trees and bushes because new bark is higher in protein than old bark, and there is a greater ratio of bark to wood and there’s more needed nutrients in the bark.
Deer also need water every day. In freezing weather, Rue found deer will eat snow and lick ice, but prefer eating melting snow for its much higher water content.
To read more on the subject check “Winter Feeding of Deer and Turkey,” a 26-page document available on the PGC’s website www.pgc.state.pa.us. And to get a copy of Rue’s new book, “Whitetail Savvy,” go to