Deer are very adapted to harsh winters. Do not feel sorry for them and start feeding them now when you haven't been feeding them all winter. It does more harm than good. Deer are ruminants meaning they have four-chambered stomachs. Their digestion relies on a community of microorganisms to help break down and digest their food. They can processes large quantities of low-nutrient foods. Deer love corn, it's easily in their top 5 most preferred foods and is the most common food people feeling sorry for them feed them in the winter. The issue is that breaking down and digesting corn requires a very different microorganism community than what the natural food deer are currently eating requires. This means, if deer go from eating natural food to corn, they will not digest it properly. At a minimum they will get little if any good out of the feed and will simply starve more. At worst, they will die of acidosis. You ask what that is, see this article: Recent Article Elk and deer are much the same in their digestive biology and deer are just as likely to die of acidosis.

In the winter deer are primarily browsers. They are well adapted to and capable of browsing. They feed on the twigs of bushes and low growing trees as these are generally the most nutritious food source available in winter. Winter can cause to yard up because of extremely heavy snow fall that last over extended periods of time. When I say heavy, I am talking in excess of 2 feet. In general, deer and turkeys are well adapted to winter survival. See here for further info: Winter Feeding of Deer and Turkeys

So you ask what can I do to help the deer? First and foremost is to keep their numbers at a natural carrying capacity for the habitat they live in. That would be somewhere around 20-30 deer per square mile of available habitat for this time of year. The only natural predator deer have in most areas currently are coyotes. Coyotes are not overly effective predators on deer. They will prey on fawns, smaller deer and sickly deer, but generally do not prey on adult deer. That leaves hunters to control the deer population.

The other thing is habitat management. Deer like "edge" it is why you always see them at the edge of woods. Whether it be your backyard or the side of the road. Edge creates sunlight and sunlight makes deer food. Big tall mature forests are good for deer to an extent. The mature oaks trees make acorns and acorns are the #1 most important deer food. However, acorn failures happen and acorns don't last all winter. Agriculture is also a huge food source for deer in farmland areas. However, today's modern farming doesn't leave much food behind in the winter for deer to eat.

Logging, specifically clear cutting areas of forest create edge and deer food. The stumps left behind grow sprouts and deer love to eat these sprouts. Both in the spring and summer as green new growth and in winter as browse. However, it's really too late to do either population or habitat management right now.

So how can you help the deer right now? Cut some trees down! If you have any of these species: Cedar(white or arborvitae), Apple(crab or domestic), Sassafras, Red maple, Flowering dogwood, Alternate leaved dogwood, Basswood,Staghorn sumac, Elderberry, Red berried elder, Mountain ash, Highbush cranberry, Highbush blueberry, Willow species, Silky dogwood, Red osier dogwood, Honeysuckle, Nannyberry, Cucumber tree(magnolia), Hemlock, Wild raisin, Arbutus, White ash, Sugar maple, Oaks(especially of the white family), Black birch, Yellow birch, Hickory, American chestnut, Black cherry, Witch hazel, Spicebush, Choke cherry, Elm, Black walnut, Shadbush, Winterberry, Lowbush blueberry, Butternut, Black ash, Hazelnut, Wild grape, Bush honeysuckle and Leatherwood you can give deer some food.

Break out the chainsaw! Cut these trees down... When the trees fall, their tops which were well out of reach of deer are now within reach of deer. The deer can now browse on them and obtain natural food their stomachs are used to digesting. As a bonus, these trees will send up stump sprouts in the spring the deer with relish. If you want to get fancy, you can do "hinge cuts" on these trees. You basically cut the trees 75-80% through the trunk and then push it over on its side. The area of the trunk you didn't cut lets the tree live but it's now laying on its side where the deer can get access to it. In the spring, the whole tree will begin to sprout and in doing so will become prime deer food. An area of several hinge cut trees provides excellent bedding cover for deer as well.

If you must feed the deer corn. Make sure you choose a sheltered location that is near thermal cover(think hemlock, white pine, cedar, other pines, etc.) Also, you must feed them year round! This allows the microorganism community in their stomach to be capable of digesting corn or what ever other feed you choose to feed them.

Deer and turkeys are very winter hardy species and are capable of handling brutal winters, even like the one we are experiencing this year. Sometimes our best intentions can actually hurt the wildlife we love so much.