For the birds: Modern scarecrows go high-tech
The old-fashioned scarecrow has been replaced by mechanical marvels such as this solar-powered California ScareCrow with arms that move in a random pattern to keep birds away from vulnerable crops.
That ragged straw-stuffed mannequin that stands watch over a farmer's fields has long been a familiar figure of the American rural landscape.
As kitschy decoration for the fall season or traveling companion of Dorothy and Toto, the scarecrow has become more a nostalgic icon of agriculture than an effective tool for shooing away birds. But thanks to technology, science and innovation, farmers now use a new legion of techniques and modern "scarecrows" to protect their crops from pesky critters.
Dirk Van Vuren, wildlife, fish and conservation expert at the University of California, Davis, said modern scaring devices such as noisemakers that sound off periodically add an element of surprise lacking in stationary scarecrows, which quickly become a part of the scenery and lose their fear factor. New power-operated scarecrows that move and pop up intermittently via a timer can be "quite effective" at deterring birds and other wildlife if used in combination with a noisemaker, Van Vuren added.
"The old scarecrows like in 'The Wizard of Oz' made out of straw that's fixed don't work because animals get used to them," he said. "They have to move. The ones that don't move lose their effectiveness very quickly."
A fairly simple bird deterrent that requires no mechanization is securing strips of highly reflective aluminized film ribbons on posts or to plants throughout the field. The reflective tape vibrates in the wind, creating shimmers from the sun, and generates a strobe effect that annoys birds, said Van Vuren.
But not everyone finds reflective strips to be effective.
Nicholas Miller, who grows winegrapes in Santa Barbara and San Luis Obispo counties and lemons and avocados in Ventura County, said the tape is probably the least effective of all the methods he's tried.
The tape may make farmers feel better that they're trying to protect their crops, said Dana Merrill, who grows 4,000 acres of winegrapes in San Luis Obispo County, but he doubts it really does anything to keep birds away.
"When you see the birds carrying it away to build their nests with it, to me, it doesn't seem like that good of a deterrent," Merrill said, chuckling.
But Richard Nickerson, an inventor in Encino, is taking the moving scarecrow idea to a new level by using reflective tape in combination with a solar-powered mechanical scarecrow to outsmart the most audacious birds.
Neither made of straw nor resembling a man, Nickerson's "California ScareCrow" has "arms" that each stretch 17 feet long, much like fishing poles with red and silver mylar strips attached. The arms move flexibly in the wind and are motorized by solar panels that randomly rotate the arms in clockwise and counter clockwise intervals so that birds cannot predict the regular movements as they do with other deterrents, he said.
"You get a lot of fluttering and movement that the birds don't like," he said. "It makes it very unsettling for the birds. The mylar ribbons on the wands increase this unsettlingness for the birds."
The 18-pound unit is lightweight enough that it is easy to move and store when not in use, he added. It is photocell activated so it comes on at first light and goes off at dusk.
Nickerson, who owns a 70-acre vineyard in Kelseyville, said he came up with the idea for the mechanical scarecrow after trying many other methods for frightening birds away from his winegrapes.
"We were losing 25 to 30 tons of grapes to the birds, and I tried everything that I could find to keep the birds away. Nothing worked," he said. "So I decided to come up with my own idea and it has been very effective."
Miller said he's had some luck with air guns because the loud noise does scare birds, but they also startle people who are not used to hearing them. That can be a problem for vineyards that want to preserve wine country's romantic allure. Merrill said he's gotten away from using noisemakers because of complaints from his neighbors.
"The neighbors absolutely hate those things, and I don't really blame them because it does drive you absolutely crazy," he said. "You feel like you're in a war zone."
He also worries about the liability of having any kind of shotgun or pistol around the farm, even if they are used for making noise. Accidents can happen if employees fail to use any device properly, "and that's not good for workers' comp," he added.
"We've kind of come to the conclusion that we're kidding ourselves a lot of times if we thought that we were scaring the birds away with these noisemakers," said Merrill. "When it really comes down to it, after the people have gone home, you just drive around the vineyard, you see the birds are obviously still there, and they're coming out to feed again and there's nobody there."
One method that Miller and Merrill say they've had success with is hiring falconers to bring birds of prey to their vineyards. The presence of the falcons, trained to hunt starlings and other destructive birds, naturally keep other birds away. Both growers say they've been using the falcons for several years, and the technique works best in larger vineyards where the falcons have room to fly.
Because the falcon's knack for chasing and hunting specific birds is a trained ability, the bird will not pass this skill on to its offspring nor will it teach its young how to do it. So farmers who want this service must rely on a falconer and pay the hefty price.
"It's not cheap, that's for sure," said Miller. "But we found it to be another successful tool to use in our toolbox."
Van Vuren said researchers at UC Davis developed a recording that mimics the cries of a crow in distress. The idea is that upon hearing the recording, the other crows would respond to the fake death cries and leave their roost.
"Recently they've been trying this in orchards and putting out these tape recorders," said Van Vuren. "They're all automatic and they play this sound at intervals, and recent studies have shown that you can disperse crows from an orchard."
For grape growers, the one sure way to keep birds from eating the crop is to cover it with netting, said Domenico Carinalli, a winegrape grower in Sonoma County. This method is expensive and very labor intensive, but it works, he added.
His vineyard is located in an area of Sebastopol where plentiful trees and creeks make desirable habitat for starlings, which love to munch on grapes. With a high-value crop such as pinot noir, Carinalli said the costly netting-about $300 an acre-is a necessary investment for preventing detrimental losses on his farm.
"We have a very severe problem, so the only real way to protect the crop is to net them," he said. "Then you don't have to worry about it; it's a done deal."
Aside from birds, farmers encounter a variety of vertebrate pests in the fields that not only damage crops but also create numerous other problems for farmers. Burrowing animals such as gophers and ground squirrels can erode farmland and damage the root system of trees. They also eat the fruits and nuts in orchards. Other wildlife such as coyotes kill livestock and gnaw on irrigation lines, saddling farmers with additional damage.
One of the most cost effective ways to deal with such pests is to kill them, said Van Vuren. But increasing regulatory restrictions and opposition by the public have steered many property owners to look for alternatives. Some are growing different genetic strains of crops that are more resistant to damage, while others are modifying their cultural and land management practices to deter potentially destructive animals from inhabiting their farms.
Van Vuren said another way farmers protect their crops from land-dwelling animals is by planting diversionary crops, typically something that the animals love but the farmers don't care about. In forest regeneration, researchers found that by broadcasting diversionary food such as sunflower seeds over the areas they want to protect, destructive vermin such as squirrels will leave young seedlings alone and eat the sunflower seeds instead. Researchers have also been able to divert black bears from chewing the bark on redwood trees by feeding the bears woodchips soaked in sugar.
Using diversionary crops and food can be expensive, said Van Vuren, but "if you do it at the right time and the right dosage, it's cheaper than the damage you'd suffer if you don't do it." He advises farmers to examine the magnitude of their loss and do a cost benefit analysis before plunging into any method of damage control.
"It's not uncommon for growers to spend more money on control than they're saving in reduced damage," he said. "In some instances, it's better just to absorb the cost of damage than it is to do any control at all."
Miller said pest control is definitely figured into his farm's budget every year.
"You could easily wage a war and maybe be successful but you're going to go out of business doing it," he said.
(Ching Lee is a reporter for Ag Alert. She may be contacted at firstname.lastname@example.org.)
Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.