Birds are attracted to cherries, often sampling the fruit as soon as it shows color, resulting in significant crop loss for growers. Protecting the harvest requires a layered approach, combining physical barriers and scare tactics. Understanding the behavioral patterns of common fruit-eating birds allows for the implementation of effective, non-lethal methods to ensure a successful cherry yield.
Physical Exclusion Methods
Physical barriers are the most effective solution for protecting ripening cherries, often reducing bird damage by upwards of 85%. Bird netting creates an exclusion zone, preventing all access to the fruit. Mesh size is important; openings around 0.62 to 0.7 inches (1.6 to 1.8 cm) exclude most pest birds. Finer mesh prevents birds from entangling their feet or pecking through the netting.
For large trees, do not drape the netting directly over the canopy, as birds can feed on fruit touching the mesh. The net should be supported by a simple frame of poles or PVC pipe, holding the material away from the cherry clusters. This creates a secure, tent-like enclosure around the entire tree or row.
Proper installation requires securing the netting completely at the base, gathering it tightly around the trunk or anchoring it to the ground with stakes or weights. Birds will quickly exploit any gap at ground level to gain entry, which can lead to the bird becoming trapped inside. White netting is highly visible, helping to prevent accidental entanglement, and reflecting sunlight, which may contribute to better fruit quality.
Visual and Auditory Deterrents
Deterrents rely on triggering a natural avoidance response based on perceived threats. Visual deterrents include reflective flash tape, shiny aluminum pie pans, or old CDs, which move in the breeze and produce unpredictable flashes of light. These erratic movements discourage birds from landing near the tree. Decoys of natural predators, such as plastic owls or hawks, can also be placed within the canopy to simulate a threat.
Auditory deterrents, like automated noisemakers or units broadcasting distress and alarm calls, signal danger to nearby flocks. To maximize the effect, speakers should be positioned slightly above the tree canopy for optimal sound dispersal.
The effectiveness of any visual or auditory device diminishes rapidly as birds learn the threat is harmless, a process called habituation. To counter this, move the deterrents frequently, ideally every few days, and randomize the timing and sequence of auditory signals. Combining visual and auditory methods can prolong the overall effectiveness, creating a more complex perception of danger.
Habitat and Resource Management
Managing the surrounding environment and resources can reduce bird pressure. Birds seek cherries not just for food, but also for hydration, especially during dry weather. Placing a clean, accessible water source, such as a bird bath or shallow dish, away from the cherry trees can distract birds from the fruit.
Planting a decoy crop offers birds a more appealing alternative. Mulberries are an excellent choice because they ripen concurrently with cherries and often possess a higher sugar content, making them a preferred food source. Providing an abundance of a different, less valuable fruit reduces the intensity of feeding on the main crop.
The timing of the harvest plays a significant role in minimizing loss. Since birds begin feeding as soon as the fruit starts to color, picking the cherries at peak ripeness minimizes the window of opportunity. Some gardeners also use specialized, non-toxic sprays containing methyl anthranilate, a food-grade compound derived from grapes, which makes the fruit temporarily unpalatable without causing harm.