White-tailed deer (Odocoileus virginianus) are highly adaptable herbivores, meaning they consume a wide variety of plants to meet their nutritional needs. This generalist browsing behavior often leads them to interact with common forest and landscaping trees, including various species of maple (Acer). The question of whether deer eat maple leaves depends heavily on the season, the specific maple species, and the availability of other preferred forage.
Seasonal Palatability of Maple Leaves
Deer readily consume maple leaves, but their preference is linked to nutritional quality throughout the growing season. Consumption is highest during the spring when new foliage is soft and highly palatable. These young leaves contain greater concentrations of protein and moisture, necessary following the lean winter months.
As summer progresses, mature maple leaves become less appealing to browsing deer. The foliage develops higher concentrations of structural carbohydrates, such as cellulose, making the leaves tougher and less digestible. Simultaneously, secondary compounds, like tannins, increase, which can bind to proteins and reduce nutritional benefits. Browsing on mature leaves increases when more desirable food sources, such as forbs and agricultural crops, become scarce.
Variation by Maple Species and Toxicity
The specific species of maple significantly influences whether a deer chooses to consume its leaves. Sugar Maple (Acer saccharum) is generally considered a palatable and nutritious browse species, and deer often feed on its fresh foliage. Conversely, non-native species like the Norway Maple (Acer platanoides) are frequently avoided by deer. This avoidance is likely due to the milky white latex sap the Norway Maple produces, which acts as a deterrent.
A serious concern is the toxicity associated with Red Maple (Acer rubrum) leaves, though this primarily affects livestock like horses. The leaves of Red Maple, particularly when wilted or dried, contain a compound that can cause severe hemolytic anemia if ingested. While deer may browse on the fresh, green leaves, they typically exhibit an innate ability to avoid the wilted foliage, which is at its most toxic state. They generally prefer to eat species that pose no chemical risk.
Browsing Maple Beyond Foliage
Beyond the seasonal consumption of leaves, deer regularly feed on other parts of the maple tree. When snow covers herbaceous plants, deer shift their diet to woody browse, which can constitute over 60% of their winter food intake. This winter foraging includes consuming the terminal buds and fine twigs of maple branches, providing a necessary, albeit less nutritious, energy source.
This type of browsing is often more destructive to the tree’s health than the loss of summer foliage. Deer frequently target young maple seedlings and saplings, consuming the tender growing tips. Repeated browsing can stunt the growth of young trees or create a distinct “browse line” in the forest understory. Furthermore, male deer rub their antlers on the bark of young maple trees in the fall to remove velvet, which can girdle and kill the sapling by damaging the vascular tissue.