Trees naturally draw birds, which can create conflicts when human and avian interests overlap. Birds seek trees primarily for safe shelter, using dense foliage for roosting and protection from predators and weather. Branches also provide structure for building nests. Additionally, trees are a rich food source, offering insects, nuts, and fruits. The goal of bird deterrence is to safely discourage these activities using humane methods that make the trees less appealing without causing harm to the wildlife.
Visual Methods for Deterrence
Visual deterrents capitalize on a bird’s natural wariness of unexpected movement or perceived threats. A common, low-cost option is the use of reflective or holographic materials, such as strips of Mylar tape or old compact discs. When tied to branches, these items flutter in the breeze and flash sunlight, creating an unpredictable light show that birds interpret as a disturbance. Holographic flash tape combines visual distraction with a subtle crackling sound as it moves, enhancing the deterrent effect.
Another approach involves deploying predator decoys, typically molded plastic owls or hawks, which exploit the birds’ instinct to avoid natural enemies. Specialized visual items like “scare-eye” balloons or diverters feature large, reflective “predator” eyes designed to confuse and intimidate. These strategies are quick to implement and require no power source, offering an immediate, if temporary, solution.
The effectiveness of any visual deterrent diminishes quickly if it remains static, as birds quickly become accustomed to non-moving objects. To prevent habituation, it is important to reposition reflective materials and predator decoys every few days. Changing the type or orientation of the decoy occasionally helps maintain the illusion of a persistent threat.
Physical Barriers and Exclusion Techniques
Physical exclusion methods are often the most reliable way to prevent birds from accessing specific areas of a tree because they create an impassable barrier. Bird netting, typically made from durable, UV-stabilized polyethylene, protects fruit-bearing trees or entire canopies. Proper installation requires the netting to be pulled taut and secured at all edges, often to a simple frame, ensuring no gaps exist where birds could enter and become trapped.
The mesh size of the netting must be small enough to exclude the target species while still permitting light and air circulation. Regularly inspecting the netting for tears is necessary to maintain its integrity and prevent accidental entanglement. While netting covers entire trees or branches, specialized anti-roosting devices serve a different purpose.
Bird spikes or wire systems are designed to make surfaces uncomfortable for landing, rather than blocking access entirely. These blunted, stainless steel or plastic spikes are installed on large, flat perching spots like structural limbs or beams, not within dense foliage. The goal is to create an irregular surface that prevents large birds from gaining a secure foothold, offering a long-term solution for specific problem areas.
Auditory and Sensory Repellents
Auditory methods rely on sounds to create an environment of danger or discomfort, prompting birds to relocate. Electronic sonic devices emit either the distressed calls of the target species or the sounds of their natural predators. It is necessary to vary the timing and type of sound to prevent birds from quickly learning that the noises pose no actual threat.
Anyone employing deterrents must be aware of the Migratory Bird Treaty Act (MBTA) in the United States, a federal law that protects nearly all native bird species. This legislation makes it illegal to pursue, capture, kill, or possess migratory birds, including their eggs and nests, without a permit. Any deterrence strategy must be strictly non-lethal and should not be implemented if it would disrupt an active nest.
Sensory repellents offer a multi-faceted approach, targeting a bird’s sense of sight, smell, and touch. Topical repellents, such as sticky gels, can be applied to problem roosting spots on branches. Modern “optical gels” are designed to be multi-sensory, using ultraviolet light reflection that birds perceive as fire or smoke, an immediate threat signal.
These gels contain non-toxic scents, such as citronella or peppermint oil, which are unpleasant to birds but agreeable to humans. The sticky texture of the gel is also a deterrent, making the landing spot undesirable without causing harm. Use these non-toxic gels and sprays sparingly, applying them only to the specific perching or roosting surfaces to avoid damage to the tree bark or leaves.