Sugar maple trees are a significant part of the eastern North American landscape, providing both timber and the sap used to make syrup. White-tailed deer consume parts of the sugar maple tree, often leading to conflict in these forests. Sugar maples are generally considered a moderately preferred food source, or “browse,” especially where high deer populations limit more palatable options. The greatest impact is seen on young trees, where repeated feeding can hinder or prevent forest regeneration.
Identifying Signs of Deer Browsing
Distinguishing deer damage from that of other forest herbivores requires close observation of the feeding pattern. Deer lack upper incisor teeth, meaning they must bite down on a twig or bud with their lower incisors and pull against their upper dental pad. This feeding method leaves a distinctive ragged, torn, or frayed edge on the remaining stem or branch.
The ragged edge distinguishes deer damage from that of rabbits or rodents, which have sharp incisors on both jaws and leave a clean, angled cut. Deer prefer to eat the tender terminal buds and the youngest twigs of saplings, which are rich in nutrients. This browsing typically occurs up to a height of five to six feet off the ground, corresponding to the maximum reach of an adult deer. When deer populations are high, a visible “browse line” can become apparent in the forest understory, marking the upper limit of their feeding activity.
Seasonal Patterns of Consumption
The white-tailed deer’s diet shifts throughout the year, and their interest in sugar maple browse peaks during the colder months. During winter, preferred herbaceous plants and summer forage become dormant or are buried under snow. This scarcity makes the woody browse of dormant sugar maple saplings a readily available and important food source for survival.
The young shoots and buds of maple trees contain relatively high energy content, sustaining deer through periods of low food availability. Repeated browsing on the same young saplings over multiple winter seasons can cause severe stunting, a condition known as hedging. Hedging occurs when the tree is continuously pruned back to a short height. If the terminal bud is repeatedly removed, the tree cannot grow tall, and sustained damage can ultimately lead to the young tree’s death, preventing forest regeneration.
Protecting Young Sugar Maple Trees
Physical exclusion is recognized as the most reliable strategy for protecting vulnerable sugar maple saplings from deer browse. The most effective method involves installing individual tree tubes, which are plastic shelters placed around the young tree. These tubes must be at least five to six feet tall to ensure the growing terminal bud remains above the deer’s reach, preventing them from topping the tree.
The tubes also offer protection from antler rubbing damage, where male deer strip bark from the trunk to remove velvet or mark territory in the fall. Alternatively, for small clusters of trees, temporary or permanent fencing can be erected, though this must be a minimum of eight feet high to prevent deer from easily jumping over it. For protecting the lower trunk against both deer and smaller animals like rabbits, a cylinder of galvanized hardware cloth with a small mesh size can be secured around the base.
Chemical repellents offer a secondary line of defense, but they require consistent maintenance and reapplication. These products discourage deer by tasting unpleasant or smelling foul, preventing them from taking a second bite. Repellents are often weather-dependent, requiring reapplication after heavy rains or snow. They may also be less effective in areas with high deer pressure.