Looking at the winter landscape now makes me wonder how and where the deer find enough food to sustain them over the winter. Pretty bleak-looking, isn’t it?
It’s not only cold (which drives up energy costs), but the most unproductive (vegetatively speaking) time of year to be an herbivore. Do stumps, trunks, and twigs, along with scraggly raspberry vines and wildflower seed heads have any nutrition in them? How do the deer manage?
Deer are selective browsers, not grazers, which means that they sample twigs, leaves, buds, fruit, berries, nuts, etc. but are not the mowing machines that cattle or horse are in a pasture. A mouthful here, a mouthful there, pulling and ripping the tops off vegetation because they have no opposing incisors with which to bite cleanly.
There’s not much nutrition in a twig, but there might be in a bud — the plant’s storage site for rapid regrowth in the spring. That’s why I “cage” my azaleas in the winter, after watching deer consume the flower buds for several years.
Deer love nuts, especially acorns, which are full of carbohydrate. In the fall, deer preferentially select white oak acorns which are sweeter and contain less tannins, so they can store as much body fat as possible to last them over the winter.
But acorns are buried under a foot of snow in my backyard, so what else is there to eat? Twigs of dogwood, willow, sassafras, honeysuckle, and blueberry are favorite deer browse in the winter, as well as the growing tips of red cedar, and seed heads of sumac. A logging operation that left pine tree tops on the ground attracted a large deer herd in Maine (see photo below).
A logical (though unexpected) adaptation to the sparse resources of the winter might be reduction in food intake. Even though cold winter temperatures mean higher energy expenditures to keep warm, deer do reduce their food intake in winter, relying on fat reserves for up to 40% of their daily energy requirements.
That means fall feeding is most critical to insure winter survival, and the fall nut and seed crop is key to putting on the fat. What they can’t find in nature at that time, they can often find in our backyards, under the bird feeders. Twice, deer have pulled bird feeders right off the post and scarfed down the contents. I’ve learned to hang the feeders out of their reach.