A recent Bangor Daily News Outdoors column about feeding deer in winter generated a lot of discussion among readers. Many people want to help deer survive Maine’s harsh winters and assume putting out food is the best way to do that.
Feeding deer can sometimes do more harm than good. What deer truly rely on to survive winter in Maine is high-quality winter habitat — dense conifer forests known as deer yards.
As a licensed forester who has worked on many properties that include deer wintering areas, I’ve seen firsthand how important this habitat is and how much it has changed over time. Understanding what makes a good deer yard — and how landowners can maintain or improve that habitat — is key to helping Maine’s deer herd survive winter.
White-tailed deer in Maine are at the northern edge of their range and rely on mature conifer forests to survive severe winters.
Deer often travel 20 miles or more from their summer range to the same wintering areas year after year. They depend on thick stands of cedar, hemlock, fir and spruce for shelter and winter food. These forests also create shallower snow conditions that allow deer to move more easily, reach food and evade predators such as coyotes. This migration is a learned behavior passed from mothers to fawns.
Quality wintering habitat is especially important for pregnant does, which must conserve energy and avoid losing too much body weight during winter.
Wintering habitat on private forestland has been reduced and altered for many reasons, with timber harvesting high on the list. As the paper and sawmill industries expanded in the middle of the last century, demand for fiber increased dramatically. In Washington County alone, demand grew from about 155,000 cords in 1950 to roughly 400,000 cords in 1970. During the same period, deer registrations dropped from about 12,000 in 1950 to roughly 4,000 by 1982.
This period also marked the beginning of large-scale mechanical harvesting. Not long after, the spruce budworm outbreak of the 1970s and 1980s further reduced mature spruce and fir forests across northern and eastern Maine, eliminating large areas of traditional deer wintering habitat.
The state later enacted special rules to protect deer yards in the unorganized territories once regulated by the Land Use Regulation Commission. However, organized towns largely relied on local standards and often lacked the technical guidance needed to protect wintering habitat.
By the early 2000s, many forests affected by the budworm outbreak had recovered enough to be harvested again. As landowners faced growing pressure to harvest timber to pay taxes and manage investments, some harvesting practices led to fragmentation of deer yards and loss of the dense conifer canopy deer depend on.
Deer wintering areas that once exceeded 1,000 acres are now often reduced to patches of 100 acres or less. If those patches remained connected, the impact would be less severe. In many cases, however, little connectivity remains and deer must rely on isolated habitat while surrounding forests mature.
Loss of the conifer canopy is another concern. Effective deer yards typically require at least 70 percent canopy closure, dominated by conifer species such as cedar, pine, hemlock, spruce and fir that are generally more than 30 years old.
Those same trees are often among the most valuable in timber markets. As a result, harvesting that removes the largest and best trees can gradually reduce the conifer canopy and diminish the quality of winter habitat.
Maintaining mature conifer forests can be challenging, especially as landowners balance property taxes, timber income and habitat protection.
Species composition, forest age and overall size all play important roles in providing the nutrition, mobility and shelter deer need during winter.
Cedar is particularly valuable because its dense canopy intercepts snowfall and reduces snow depth beneath the trees. Cedar foliage also provides browse that is easier for deer to digest than many other conifer species, offering limited but important winter nutrition.
Hemlock is valuable for its broad crown and ability to retain heat. During a snowfall of several inches, the ground beneath a mature hemlock may remain largely free of snow. Dense stands of hemlock also block cold winds and help reduce heat loss on cold nights.
Spruce and balsam fir provide less snow interception but still contribute to winter habitat. Balsam fir serves as a secondary browse species, and research from the University of Maine has shown that litterfall such as twigs, branches and lichens like “old man’s beard” can provide important food sources.
Deciduous trees provide little snow interception or thermal protection, but their twigs are easier for deer to digest. These species often occur along the edges of conifer stands, where deer may move to feed during milder periods before returning to thicker cover during severe weather.
Species composition alone does not determine the value of a deer yard. Soil type, forest maturity, tree density, canopy closure and the size and location of the habitat also matter.
For landowners who believe they may have deer wintering habitat on their property, intensive harvesting should generally be avoided when possible. Instead, lighter harvests removing 30 percent or less of the stand can help maintain canopy cover while improving forest health by removing trees with poor form, health or vigor.
Landowners may also consider creating small herbaceous openings within or near wintering areas. These patches, often an acre or less, can be planted with clover, rye or other species that provide valuable forage during late fall and early spring. Such food sources can be especially helpful for pregnant does as winter ends.
Another option is thinning small trees within a deer yard. Using brush saws to thin understory saplings can encourage desirable species and improve the long-term structure of the forest. This approach can also help guide regeneration following heavy harvesting.
These practices can involve additional costs for landowners, but several programs may help offset those expenses. Cost-share opportunities are available through the Environmental Quality Incentives Program administered by the USDA Natural Resources Conservation Service and through the Climate Resiliency Woodswise Program run by the Maine Forest Service.
Landowners interested in these programs can contact their local NRCS office, the Maine Forest Service or a consulting forester.
