Laser Scarecrows: The Future of Crop Protection

The battle against crop damage caused by birds in the realm of agriculture is an ongoing challenge, with financial repercussions running into millions of dollars annually. Researchers have now introduced a high-tech solution to this problem: laser scarecrows. The experts demonstrated that this innovative approach can drastically reduce crop damage.
 
This study centers around the use of laser scarecrows to deter birds, specifically targeting the protection of sweet corn crops. European starlings, a common pest for farmers, were presented with fresh ears of sweet corn, and researchers observed the impact of moving laser beams on these birds. Remarkably, it was discovered that lasers significantly mitigate damage up to a distance of 20 meters from the device.
 
Study co-author Kathryn Sieving, professor of Wildlife Ecology and Conservation at the University of Florida, explains that more growers are seeking inexpensive and portable laser units like those tested in their research.
 
"Growers need big effects for affordable prices," said Professor Sieving. "If they can spend $300-$500 each for lasers to protect large fields for 1-3 weeks instead of more expensive options such as hiring people to patrol with dogs, falcons, or rifles, then lasers would be beneficial."
 
One key advantage lies in its effectiveness during what's known as 'the vulnerability window,' which is a critical period before harvest when crops are most susceptible to bird damage. This short window reduces the likelihood of birds becoming accustomed to lasers and maintaining their efficacy.
 
Sieving added: "Birds only attack sweet corn during the ripening phase (called the milking stage), which lasts only 5–10 days—so soon after it ripens, harvesting begins." She further explained how using different non-lethal deterrents combined seems effective, especially on crops with short vulnerability windows like sweet corn, since it surprises birds, making them leave fields, reducing damages by far more than 20%.
 
The research involved two types of experiments: stick trials where corn ears were mounted on sticks at various distances from lasers, and natural trials involving birds foraging on ripe corn grown in a flight pen. These trials provided insights into the effectiveness of lasers under controlled conditions and in more natural settings.
 
While lasers reduced damage marginally in stick trials, their impact was significantly more pronounced in natural trials. This outcome is attributed to the sturdiness of the sticks used, allowing birds to perch and feed while avoiding lasers. By contrast, natural corn stalks were more susceptible to the deterrent effects of lasers.
 
Distance from the laser source also played a crucial role, where deterrence was effective up to 20 meters but diminished beyond this range, with little effect observed at 30 meters. However, Sieving pointed out that this effect seems unimportant in open fields, as birds will simply leave a field that has detectable laser protection and fly far out of its influence.
 
Sieving hopes that laser scarecrows can offer a sustainable solution for crop protection with short vulnerability windows since they're silent, unlike acoustic deterrents, which are disturbing or lethal deterrents requiring permits and time-consuming labor applications with potentially toxic secondary effects on wildlife soil and water, are often unacceptable.
 
The study is published in the Pest Management Science journal, offering hope for farmers struggling against bird-induced crop damage across the globe.