It may not be very pretty, but a new laser “scarecrow” is helping farmers to protect their sweetcorn crops from marauding birds. Developed by University of Rhode Island (URI) professor of plant sciences Rebecca Brown, the new system uses constantly moving beams of green laser light to scare off birds like starlings and red-winged blackbirds before they can tuck into a ripe ear.
Since the beginnings of agriculture, birds have been one of the greatest threats to farm crops. In 2017, Cornell University researchers estimated that an average of 16 percent of sweetcorn crops in New York State was damaged by birds, with red-winged blackbirds being the chief culprits, and Brown puts losses at up to 75 percent in some cases. Not only do they eat the corn, but they also rip at the husks, wreck tassels, and generally make the ears that survive the onslaught fit for little more than pig fodder.
Unfortunately, the scarecrows that were once a common sight in the country and can still be found standing watch over many a backyard garden simply aren’t up to the task of protecting commercial crops, so things like propane cannons, bright balloons, chemicals, shotguns, and even those weird inflatable dancing things used at sales promotions have been tried, with limited success.
Brown’s new twist on the scarecrow swaps the stuffed suits of clothes with a bag for a head for commercially available green LED lasers that have become relatively inexpensive in recent years and can be run off batteries or solar panels. It’s not a new idea. Brown says that laser deterrents have been around for over 20 years, but they have previously been used to warn birds off from indoor shopping areas and sports centers, and have only been used outdoors on a very limited scale.
The laser scarecrow is housed inside a plastic bucket that protects it from the elements and is attached to an adjustable pole to set the laser at the same height as the corn tassels. The lasers, which can cover a section 600 ft (185 m) on a side, scan back and forth, scaring the birds off.
“We think the birds perceive the laser as a solid object they need to get away from, but we don’t know exactly. We can’t get inside the head of a bird,” says Brown. “But we know from tests done using hand-held lasers that if the laser isn’t constantly moving, the birds will eventually ignore it. It works especially well if there are other sources of food nearby that the birds can go to instead of eating the corn. We’re just trying to make the corn less desirable.”
Brown has tested the system for about three years on URI fields along with two commercially available laser deterrents. She’s also sold a few of her lasers to farmers at a cost of US$500, which is considerably less than commercial systems that can run to up to $10,000. She hopes to one day make the system available for regular sale, but she says it is not a panacea.
“It’s probably going to turn out that it’s best deployed as part of a multi-tool approach to bird control, but it definitely seems to be reducing bird damage,” says Brown.
Laser scarecrows helps keep cornfields clear of bird pests [New Atlas]