Birds can cause significant damage to grape vineyards by eating the grapes right off the vines. Some of the most common culprits are starlings, crows, sparrows, finches, robins, and blackbirds. The loss of grapes to birds can result in major economic losses for vineyard owners. Fortunately, there are several effective techniques to deter and exclude birds from vineyards to prevent damage.
Why are birds attracted to vineyards?
Birds are drawn to vineyards for the abundant food source grapes provide. Grapes are soft, sweet, and full of nutritious sugars and water content that birds seek out. Vineyards offer an ideal habitat for birds with tall trellises for perching and open access to grapes. Birds also use vineyards for nesting and raising their young. The availability of food, water, and shelter make vineyards prime real estate for various bird species.
When are birds most problematic in vineyards?
Bird pressure in vineyards is highest when grapes first begin to ripen in mid-to-late summer. This is when grapes become sweet and appealing to birds. Another peak time is just before harvest, when sugar content is highest. Warm, dry conditions also embolden birds to feed more aggressively on grapes. Birds may even pick grapes before they are fully ripe to get an early source of juice. Being aware of these patterns can help focus bird management efforts during vulnerable times.
Deterring Birds from Vineyards
There are several strategies to make vineyards less hospitable to birds and deter them from feeding on grapes. An integrated approach combining multiple techniques is most effective for bird control.
Auditory bird deterrents
Noise-making devices such as propane cannons, bird guard alarms, and distress call systems create loud sounds that startle birds and make them wary of entering vineyards. These sounds remind birds of danger and discourage them from settling in and feeding extensively. The noises can be random, automatic, or activated by motion sensors when birds are present. Using multiple deterrents and moving them periodically prevents birds from becoming habitual to individual sounds.
Device | Description |
---|---|
Propane cannons | Automated cannons that produce loud explosions |
Bird guard alarms | Emit predator calls, distress cries, and other alarming sounds |
Distress call systems | Broadcast recordings of birds in distress |
Visual deterrents
Visual scare tactics like reflective tape, balloons, hawk kites, and effigies of predators can discourage birds from vineyards. The glint and motion of these devices triggers birds’ innate fear of predators. Using bright colors, hanging items at different heights, and repositioning regularly maximizes effectiveness. Birds will avoid areas where they sense threats overhead.
Device | Description |
---|---|
Reflective tape | Shiny metallic tape that flashes in sunlight |
Scare-eye balloons | Balloons with large predator eyes |
Hawk kites | Kites in the shape of hawks or falcons |
Predator effigies | Scarecrows or fake hawks, owls, or snakes |
Chemical bird repellents
Non-toxic chemical compounds can be applied directly onto grapes to make them unpalatable to birds. The grape-based repellents create a bitter, burning sensation that birds dislike. Some products incorporate grape extract with other oils, spices, and compounds to amplify the unpleasant taste. Reapply after rain or as grapes grow to maintain effectiveness.
Excluding Birds from Vineyards
Physical exclusion techniques provide a barrier between birds and grapes to prevent access. This is the most direct protection method to stop birds from reaching grapes.
Bird netting
Netting is the most common and effective exclusion technique. Special UV-stabilized polyethylene or nylon mesh nets are draped over vine canopies and anchored to prevent entry. Proper installation ensures nets don’t contact grapes. Nets should be applied just before grapes ripen and removed after harvest. Leaving nets on too long traps moisture and promotes fungal diseases.
Overhead wires or grids
Wires or wire grids installed over vines block birds from flying in or landing on grapes. Horizontal wires should be spaced 10-20 inches apart to allow workers access. An electric current can be applied to wires to give birds a mild shock upon contact. Non-electrified systems require tighter wire spacing.
Individual grape bagging
Slipping small bags over each grape cluster excludes birds while still allowing sunlight and airflow. This meticulous method may be used for high-value grape varieties. Bags must be secured well and monitored for damage.
Bird Management Practices
In addition to deterrents and exclusion, vineyard management practices can make the environment less suitable for birds. Cultural strategies that minimize cover and food sources send the signal that vineyards are inhospitable.
Canopy management
Avoid dense, overlapping grape canopies by pruning judiciously. Thin canopies allow better air circulation and light penetration while removing protected hiding spots for birds. Reduce second or double crop bunches which are hidden within dense foliage.
Prompt harvest
Harvest grapes as soon as maturity targets are reached. Leaving ripe grapes hanging gives birds more opportunity to feed. Plan harvest logistics to pick all varieties efficiently.
Remove alternative food and shelter
Clear the vineyard floor and borders of weeds that produce seeds or berries. Eliminate standing water sources, brush piles, and unused structures that could attract and provide cover for birds. A clean, well-manicured vineyard is less habitable.
Coordinated efforts
Work with neighboring growers to implement bird deterrence across a wider area. Birds will seek unchecked vineyards if only individual sites use controls. Regional coordination expands effectiveness.
Trapping Problem Birds
For persistent bird invaders, trapping and removing individuals may be warranted. Consult regulations first, as permits and restrictions apply for trapping native bird species. Specialized traps and baits are available to target problem vineyard birds.
Funnel traps
Funnel-shaped traps lure birds in through side openings. Once inside, birds are unable to find the exit holes, trapping them unharmed until the grower frees and relocates them away from the vineyard.
Mist nets
Fine mesh mist nets are difficult for birds to detect. Strategic placement in flight paths allows birds to fly into the nets, becoming harmlessly ensnared so they can be collected and transported.
Baited traps
Certain birds have an irresistible attraction to particular bait foods. Traps containing sunflower seeds, cracked corn, or other lures trap specific species for relocation. Proper bait selection is critical for target specificity.
Conclusion
Protecting vineyards from bird depredation requires diligence and an integrated pest management approach. No single method provides complete control. Deterring birds, excluding access, modifying the vineyard environment, and trapping relentless offenders together can successfully minimize grape losses. Consistent monitoring along with timely implementation and adaptation of techniques allows vineyard managers to stay one step ahead of their feathered foes. With a little advance planning and strategic effort, growers can have their grapes and ward off the birds too.