Deer are common inhabitants of many landscapes, foraging in diverse habitats from forests to suburban areas. Understanding their diet is important for appreciating their ecological role and managing interactions with human activity. This includes examining specific food sources like walnuts.
Understanding Deer Diet
Deer are herbivores, consuming only plant matter. Their foraging behavior primarily involves browsing on tender shoots, leaves, and twigs of woody plants. They also eat forbs (broad-leaved herbaceous plants) and mast (nuts and fruits).
A deer’s diet shifts seasonally, reflecting plant availability and nutritional content. During spring and summer, they favor fresh foliage and berries, which are high in protein. As autumn progresses, their diet incorporates hard mast like acorns and other nuts, providing fats and carbohydrates for winter energy reserves. In colder months, when other options are scarce, deer turn to woody browse, including twigs and bark, to meet their nutritional needs.
Deer and Walnuts
Deer generally do not prefer black walnuts. The extreme hardness of the shell makes them difficult to crack. Black walnut husks also emit a pungent odor that deer dislike. While deer avoid the nuts, they may consume tender leaves, young shoots, or small seedlings of black walnut trees, particularly during periods of food scarcity.
Black walnut trees produce juglone, a chemical found in their roots, leaves, and fruit husks. This compound is toxic to many other plant species. Deer appear to be largely resistant to juglone’s effects, and their specialized digestive system processes various plant compounds. English walnuts are less common, but deer may browse on them, finding them more palatable than black walnuts, though overall walnut consumption remains low.
Practical Considerations for Walnut Tree Owners
Deer interact with walnut trees beyond nut consumption. Young walnut trees are susceptible to browsing damage, where deer nip off buds and tender shoots. Buck rubbing is another concern, as male deer rub antlers against tree bark, particularly in fall, which can shred bark and injure or kill young trees.
To mitigate damage, several strategies can be employed. Installing physical barriers like fences, ideally eight feet tall, effectively excludes deer. Individual tree shelters or wraps protect young trees from browsing and rubbing. Chemical repellents, which deter deer through unpleasant odors or tastes, can also be applied. These repellents require regular reapplication, especially after rain or new growth, and their effectiveness diminishes under significant foraging pressure.