Laser scarecrow deters murders

America’s enthrallment with corn can crop up in strange ways. Recall the internet-enabled rise to fame of Tariq Day, also known as “The Corn Kid,” in 2022. Day’s love of corn, which, thanks to modern technology, he reiterated time and time again on the screens of our smart devices, granted him luminary status in the world of corn.

There is, perhaps, a rational explanation for this irrational exuberance.

As one of the U.S.’ leading agricultural contributions, corn fields currently occupy 80 million acres, or 3% of the land within our nation’s borders. Domestically, corn growth contributed $164.7 billion to the U.S. economy in 2021. On a global scale, the U.S. accounts for ~30% of the world’s production of the crop.

A perpetual problem for corn growers is the persistence of predators — particularly those of the avian persuasion. Hungry birds cost farmers millions of dollars annually in damaged goods alone.

The classic scarecrow, long a lonely emblem of farm fields, just isn’t warding off birds like it used to. There’s a reason why a group of crows is called a murder. Our corn is at stake.

In response, growers have sought alternate methods to keep crows away. Armed patrolmen, toxic avicides, bright flashing lights, and acoustic scaring devices that use propane cannons or blank shotgun shells are now deployed to scare the birds and, for that matter, anyone else within a mile radius.

Understanding that the “out of sight, out of mind” (or, in this case, out of earshot) principle is the corn growers’ best-case scenario, researchers from the University of Florida and the University of Rhode Island are collaborating to investigate the use of laser-armed scarecrows to deter birds.

Using a model laser scarecrow previously developed at the University of Rhode Island, which looks less like a traditional scarecrow and, in fact, much more like a traditional laser module, the researchers presented flocks of European starlings with fresh ears of sweet corn within an enclosure.

The team performed two tests. In a “stick trial,” the researchers stuck corn on a wooden stake to simulate a stalk. In a subsequent “natural trial,” they placed real corn stalks at various heights.

Upon concluding the trials, the team determined that the use of lasers as a scarecrow mechanism reduced crop damage — marginally in stick trials and more substantially in natural trials. The prospect for crop damage, they found, increased as the laser distance increased. The research ultimately showed signifi- cant treatment effects when the corn was positioned up to 20 m from the laser scarecrow.

Though performance varies in true field environments, the researchers believe that the laser scarecrow can be just as effective, if not more so, as more disruptive methods for preventing corn-killing murders. Now, if it only had a brain.

The research was published in Pest Management Science (www.doi.org/10.1002/ps.7888).