Squirrels do eat tree bark. While it might seem like an unusual food source, it is a known behavior, particularly at certain times of the year. Though typically associated with nuts, seeds, and fruits, bark consumption is a documented part of their diverse diet.
Reasons for Bark Consumption
Squirrels consume tree bark for several reasons, often driven by survival needs. One primary motivation is nutritional; the inner bark, known as the cambium layer, contains sugars and other nutrients that squirrels can access. This becomes especially important during periods when their preferred food sources, like nuts and seeds, are scarce, such as in winter or early spring.
The need for hydration also prompts bark eating, as squirrels can obtain moisture from the sap within the trees, particularly during dry conditions.
Furthermore, gnawing on bark helps maintain their dental health. Like other rodents, squirrels have incisors that grow continuously, and chewing on hard materials like bark helps keep these teeth worn down to a manageable length. This behavior prevents their teeth from becoming overgrown, which could interfere with their ability to eat.
In some instances, squirrels may also strip bark to gather materials for nest building, using the soft inner bark as bedding.
Effects on Trees
The impact of squirrels eating tree bark can range from minor cosmetic damage to severe tree health issues. Squirrels typically create gnaw marks, or they might strip away patches of bark, exposing the tree’s inner layers. This damage can sometimes lead to what is known as girdling, where a complete band of bark is removed around the trunk or a branch.
If the girdling encircles the entire circumference, it disrupts the flow of water and nutrients, potentially leading to the death of the branch or even the entire tree.
Younger trees or specific species with thinner bark, such as maple, elm, apple, birch, pecan, sycamore, and beech, are particularly susceptible to damage. Visible signs include exposed wood, shredded bark, or areas where the bark appears peeled away.
Beyond direct damage, open wounds on trees increase their vulnerability to diseases, fungi, and insect infestations, which can further compromise the tree’s health and lead to decay.
Protecting Your Trees
Protecting trees from squirrel bark damage involves a combination of strategies to deter their activity. Physical barriers are an effective method, such as wrapping the tree trunk with metal flashing or wire mesh. These materials should be at least two feet wide and positioned about five feet off the ground, making it difficult for squirrels to climb or jump over.
It is important to secure these barriers loosely to allow for tree growth and avoid girdling the tree.
Repellents can also be used, with commercial options containing capsaicin or bitter-tasting compounds. Homemade solutions, such as hot pepper spray, require frequent reapplication, especially after rain.
Modifying the habitat around your trees also helps; trimming branches that provide squirrels easy access from nearby structures or other trees can limit their reach.
Some homeowners also provide alternative food sources, such as squirrel feeders with nuts and seeds, placed away from susceptible trees, to divert their attention.