Independent Three-Year University Study Confirms: Automated Laser Deterrents Reduce Bird Damage in Wine Grapes

Bird damage is one of the most persistent and costly challenges facing wine-grape growers. A five-state survey estimated more than $70 million in annual losses, while Michigan growers report average crop losses of around 9.2% each season.

With growers looking for effective ways to protect their crops, automated laser deterrents have emerged as one of the most promising tools for reducing bird pressure in vineyards. But how well do they actually work—and does their effectiveness hold up beyond a single season?

An independent field study by Michigan State University Extension and Purdue University’s College of Agriculture set out to answer those questions. Researchers evaluated the AVIX automated laser system from Bird Control Group over three consecutive growing seasons, from 2022 through 2024, at the Northwest Michigan Horticulture Research Center. 

The results showed that the laser reduced grape damage, with the effect observed across all three years of the study.

Study design

The trial was conducted in a 2-acre research vineyard with 14 north-south rows and six wine-grape cultivars: Pinot Gris, Riesling, Cabernet Franc, Chardonnay, Pinot Noir, and Pinot Blanc. The cultivars were randomly distributed, with all six represented in both of the zones being compared.

One section was protected by one AVIX automated laser bird deterrent. The system swept across the grape canopy along changing, unpredictable routes during periods of peak bird activity, primarily in the early morning and evening, throughout fruit ripening.

An adjacent section was left unprotected as a comparison. Buffer rows were excluded from the analysis to reduce the chance that activity in one zone would influence the other.

Near harvest each year, researchers assessed a total of 5,400 grape clusters, looking at two measures of bird damage:

• Damage incidence—whether a cluster showed any evidence of bird damage, including pecking, tearing, puncturing, crushing, plucking, or berry removal.
• Damage severity—the proportion of berries within a damaged cluster that were affected.

In 2024, the researchers added another source of data: passive acoustic monitoring. An automated recorder was placed in each zone to capture bird sounds, which were then analyzed using three acoustic indices—the Acoustic Complexity Index, Acoustic Diversity Index, and Bioacoustic Index—as a general measure of biological activity. BirdNET software was also used to identify the bird species detected in each zone.

Results

The study concluded across three seasons in this Northwest Michigan vineyard, laser protection was associated with lower grape-damage severity, lower damage incidence, and lower bird acoustic activity.

Here’s a closer look at what the researchers found.

Laser use reduces bird damage to grapes — In the 2-acre field trial, the laser-protected area showed a 37% reduction in damage incidence and a 9% reduction in damage severity compared with the unprotected area.

The effect was sustained across three seasons — acoustic monitoring showed consistently lower overall bird activity in the laser-protected area across all three years. At the same time, damage incidence varied from year to year, reflecting changes in regional bird pressure between seasons.

Bird species respond differently — Around 60 bird species were identified during the study, and their responses to the laser varied. Notably, the laser was more effective at reducing activity from known fruit-feeding species such as the American tree sparrow.

Berry color alone doesn’t predict bird-damage risk — growers shouldn’t rely on berry color alone when assessing risk. In this study, the cultivars with the highest and lowest damage incidence were both white-fruited varieties.

Sustained effect across three seasons

One of the biggest questions with any bird deterrent is what happens after birds have had time to get used to it. Visual and auditory deterrents can lose effectiveness when birds learn that a device poses no real threat.

This study is particularly interesting because it followed the same system over three consecutive growing seasons rather than looking at a single year. The reduction in both damage incidence and severity was observed in each of the three years.

The way the laser operates is also relevant. Instead of following a fixed or predictable route, it moves along continuously changing patterns designed to make it harder for birds to anticipate the beam.

Beyond the study: measuring economic impact

The study provides growers with independent, multi-year evidence that automated lasers can be an effective tool for managing bird pressure.

But proving that a deterrent works is only part of the equation. For many growers, the next question is: how quickly can it pay for itself?

The study did not assess the economic impact of laser use, so it does not provide data on labor savings, reduced netting or other deterrent costs, crop value protected, or return on investment. Those factors will vary depending on the vineyard, bird pressure, crop value, and existing management practices.

It is also worth noting that laser deterrents are generally most effective when they can provide consistent protection across the area at risk, rather than leaving significant portions of the food source unprotected.

Growers using automated laser systems have reported reductions in bird presence of up to 90%, with some reporting a return on investment within 12–18 months. These figures come from individual grower experiences rather than the university study and should not be treated as guaranteed results.

To explore the potential economic impact of laser bird deterrence, see our customer’s case studies.

Source: Nasrollahiazar, E., Grimes, S.E., and Pijanowski, B.C. “A Moving Green Laser Reduces Bird Damage to Grapes in a Michigan Vineyard.” Michigan State University Extension / Purdue University College of Agriculture.