Birds can be a common grape predator in the Northwest US in particular. There are fewer problems with birds in the warm California vineyards, as the winged creatures tend to migrate further north for the summer, flying south to warmth when the north gets cool (and harvest is over).
Birds in the Northwest have traditionally nested and dined in the numerous orchards (apples, pears, peaches, apricots, cherries, and nuts, depending on location) and the many forested areas in the Northwest. With the great increase in vineyard land in Oregon and Washington over the last twenty years, the birds have found a better-tasting dinner available to them than before--sweet grapes--and there is just more of it. In the past, the vineyards, fields, and orchards were smaller and intermixed with other crops, but today, with the tremendous success and popularity of wine, vineyard land is replacing other farm usage. Large flocks of birds can all feast together now without having to constantly forage. Bird populations are increasing, too, and there have been changes to migration patterns due to the warmer climate changes such as the El Niño/La Niña influence.
The most persistent grape-eating birds in the Northwest tend to be starlings, robins, and in some areas, magpies.
Certainly, not all vineyards in the Northwest face a bird problem. But when the birds have indeed chosen an area to nest and feed, the problem can be frightening and frustrating.
Repellent Methods
Repellent methods fall into three main groups: acoustical repellents such as cannons, pellet guns, and electronic sound devises with taped bird calls, distress calls, and predator noises; visual repellents including the reflective party streamer-like ribbons, shiny kite-like balloons, and somewhat realistic simulated owls and snakes; and physical exclusion, usually limited to different forms of netting.
Shooting birds has also been tried by some, but the number of birds can be daunting, and the work exacting, potentially expensive, and noisy, let alone environmentally unsound. And what do you do with hundreds of dead birdies?
Actually, Dick Erath of Erath Vineyards Winery in Dundee, Oregon once tried the kill-the-birds method. Years ago, Erath hired some local kids to shoot the birds. Erath said he "paid a bounty of 25 cents per robin and that ended my robin problem for a long time." He wound up with 300 dead robins that year. Ever creative, he developed a recipe for sautéed robin breast layered and baked with polenta, marinara sauce, and Parmesan cheese. He claimed the birds "Tasted like pigeon. They were all dark meat and mild." Robin a la parmigiana is no longer among the repertoire of harvest meals prepared at Erath.
Acoustical Repellents
Acoustical methods rely on sound to frighten birds away from sites. Birds can hear a range of sounds very much like the human range, so anything that works well to frighten a bird can also irritate a person.
Christophe Baron of Cayuse Vineyards in Walla Walla generally likes robins, but only until veraison. "Robins are good birds. They live in the orchards near my vineyards and eat insects. It makes a good natural balance. But when my Syrah turns purple, I'm not happy. It's a nightmare. I never put in my business plan to protect my grapes from nasty robins."
Initially, Baron tried propane cannons, but he said that "worked for about 30 minutes. Those birds get used to the sound, and then your neighbors are ready to kill you. Cannons are a good way to make enemies."
Keith Klingele of Snipes Canyon Vineyard in the Yakima Valley uses a range of acoustical tricks to distract the birds, for him the common robins and starlings, as well as magpies. He said: "I use an air horn, but you can't use it too early or late in the day; my neighbors say it sounds like a train. We make noise in other ways, too, with pyrotechnics from small flair guns. They explode and whistle and go 300-400 feet in the air. It works well to stir them up. Making noise directly over the canopy helps, too. We have also mounted something like an electric car horn on our four-wheeler, so we can blast away while we work in the vineyard. We can't fall back on just one mechanism. You can't use more that three to four days on just one deterrent or the birds will get used to it."
One of the newer forms of repellent is the computerized bird sound system, designed to frighten birds by alerting them to danger by playing the real distress calls of feathered friends and predators (hawks) alike. A number of companies sell these repellers, including Weitech in Sisters, Oregon. Weitech's products--Bird GardTM and Crop GardTM--use pre-recorded actual bird distress sounds as well as predator or raptor alarms and calls to effectively repel birds. These sounds are digitally mastered using high quality microchips. Those sounds are amplified and broadcast through the generating units, reaching out over one to 40 acres, depending on the model. These units (available at prices ranging from $225-$575) are designed for outdoor use, to be mounted on a wooden or metal post at a height of four to six feet.
Because the bird recordings are random, there is no pattern for the birds to get used to. These units, however, are only effective against those bird species whose distress calls are encoded on the microchip.
Tyee Wine Cellars in Corvallis uses a Weitech system with great results, according to owner David Buchanan, a big fan of the recorded bird call repellent.
Buchanan said he used to use a fine plastic netting over his vines but, "it was a lot of work to hang on both sides of the vine and tie them down. It was just too much labor, but it was successful." He has used a bird call system for the last three years and Buchanan claimed "it really works. We have to set it up about five weeks before harvest. Within hours of turning the system off when harvest is complete, we can have 200 birds back in the vineyard. We've saved money and labor and done no harm to the birds. We paid a one-time cost of $2,700 and that's been it."
Visual Repellents
The eyesight of birds is pretty good, and they do react to both movement and images that resemble their natural predators. Visual deterrents tend not be as effective as acoustical repellents, and are therefore used in combination with other systems. Used alone, their efficacy tends to be limited.
Colorful reflected streamers and flashtape--shiny plastic tape strips--tied to the vine rows move with the slightest air movement. From a bird's eye view, the entire vineyard appears to be a moving target, in motion.
Erath first saw them in use in California, redand silver glimmering strips in the vineyards and brought the idea home to his own vineyards. He created a "sacrificial cane in each row of the vineyard by stripping it of leaves and placing the tape on the end." He said: "I pull the cane out of its trellis and the cane jumps from its lack of weight. Imagine yourself a bird and you see below you a whole vineyard becoming a light-reflective sea of red and silver." Erath used other visual repellents including vinyl owls and hawks from China, and vinyl balloons, so he said "it always looks like the Fourth of July around here." Erath also used a propane cannon as well, to keep the mix lively and without detectable repetition. He said: "I reinforce it all with lead." Meaning, of course, a shot gun.
Klingele also likes mixing it up with the use of a big kite-like balloons (manufactured by Biconet) called the Allsopp Helikite ($169 to $195). The balloons last about three weeks before coming down, and are a cross between a balloon and a kite.
They are lighter-than-air like a balloon, but tend not to get knocked down by the wind like a regular balloon. Winds up to 25 mph actually force it up! Over 25 mph the drag caused by the balloon becomes too much and the Helikite is forced down. They will also come down in the rain due to the weight of water, but will relaunch automatically when the rain has dried off. The Helikite bears no resemblence to a bird, but Klingele said, "it doesn't have to really look like a bird to work scaring them off."
Physical Exclusion
Physically restricting birds from the crop with netting is the best way to guarantee grape protection. But it is also the most expensive option.
Klingele is lucky, he said, because "if I had more bird pressure, I would wind up netting. It is so expensive, so I am glad all my other means are still working for us."
But a number of Washington vineyards have now limited bird control to one reliable method: netting.
Baron of Cayuse Vineyard first saw an article on machine-assisted netting in a vineyard magazine. He traveled to Wild Horse Winery in Sonoma to see one in use. The machine and netting are supplied by Wildlife Control Technology and Baron was the first in Washington to use the system. He has sworn by the system now for four years.
The machine itself cost $8,500, and Baron estimated it costs about $1,000 an acre to purchase the reusable netting.
The process is not without a labor-intensive element. While the machine moves down the rows to place the netting over the row, people on each side of the row have to spread it over the vine and secure it.
"The beauty of it, " Baron said, "is that once we are done with the heavy grade netting, the machine rewinds it on a spool to reuse next year."
He continued, "We have had no problem with birds. We put it on just after crop thinning and just before veraison, in the ten-day window of late July or early August."
Hugh Shiels of DuBrul Vineyard in the Yakima Valley tried a whole variety of bird scare tactics, from squawkers to propane cannons and mylar strips. He said "We even shot to kill."
Last year, Shiels tried netting. "It works! It's not easy," he said, "as it needs to be spread out and secured. Without the ties, robins can get under the net when a cross wind blows. But it works.
"We also are interested in other strategies. We plan to habitat for hawks, which should reduce some of the bird population. We have so many orchards around us where the birds nest that it is frustrating. But we are not at all anti-bird. We want to improve the habitat for wildlife in general, for ducks, mallards, quail, and pheasants. We want owls here, too."
Other vineyards in Washington where the machine-driven netting is in use include the Elerding, Powers, and the Washington Hills vineyards, all in the Yakima Valley, as well as Woodward Canyon in Walla Walla.
This netting system is available through Wilson Irrigation and Orchard Supply of Yakima (among other distributors), in a number of types and grades of net.
Combinations and Creativity
Netting is the absolute system to prevent bird damage. But it is expensive and labor intensive, and therefore not for everyone.
Even if some netting is used in a vineyards, other combinations and techniques may be followed.
Harry Peterson-Nedry of Chehalem in Newberg said: "We use bird netting on anything that historically comes in late, e.g., Riesling, Gamay noir, and high elevation Chardonnay (at Corral Creek at the winery). All vineyards have two or three noise devices to scare birds, either distress recordings or propane cannons. They work pretty well in normal years, but have to be moved around. We have had some years when migratory flocks of robins or starlings have come early and we had to keep a hazing crew with shotguns around at sunrise and sunset, the times of heaviest impact for bird damage."
He added, "In general, we don't worry greatly if local birds get a little fruit, just so long as the grapes are not damaged significantly."
At the organic Brick House Vineyards in Newberg, Doug Tunnell claimed he "has four propane cannons, two shotguns, a starting pistol for specialized anti-bird boomers and other pyrotechnics, a supply of flash tape and scare eye balloons as well as a bit of netting. All this is deployed in stages, depending on pressure. Some years we are able to get by without turning the vineyard into what appears to be the tawdry remnants of a New Year's Eve Party in Tijuana. Some years we must do just that...and even then, we lose fruit."
Tunnell continued, "I know a vineyard manager type who said one vineyard where he worked lost ten tons of Pinot noir to birds in 1997. It was the worst year in my experience too. Since then we have been lucky. But bird pressure seems to correspond closely to weather patterns. High atmospheric pressure bringing clear skies often means low bird pressure. Low atmospheric pressure (storm fronts from out of the Gulf of Alaska and the like) brings down the flocks of migratory robins that are the most destructive bird pests.
"We try not to shoot to kill here, but you'd be amazed at how personal the struggle can become, even for the most mild mannered vineyardist." Of course, Tunnell is describing himself.
For those who face bird problems, a little fruit damage is fine. A lot of fruit damage isn't. And the options aren't as easy as one would think. wbm
Bird Behavior
• Large flocks of birds are easier to scare than small ones.
• Starlings will fly 25 km from a roosting site to feed, flying at up to 70 km/hr in short bursts.
• Bird damage patterns can vary considerably from year to year and from farm to farm.
• Bird damage is usually localized and not uniformly distributed throughout an area.
• Birds are opportunists, feeding on whatever is available.
• It is difficult to break birds of the habit of feeding in a particular area once they are established.
• Birds establish their home territory in late April and May and often remain in the area until the crop ripens.
• Crops near roosting or nesting areas, woodlots, rivers, or ponds are more vulnerable than those in the open.
• Birds acclimate quickly to uniform movements or noise patterns.
• Different species of birds respond differently to various repellent methods.
• Birds can be diverted to other nearby feeding areas (lucky neighbors!).
• Birds will endure significant hardship to feed.
• Birds often follow the same flight patterns to feed.
• Birds usually feed early in the morning around sunrise and late in the afternoon around sunset.
• Birds like to drink water when they feed.
• Some birds travel in migratory flocks, while others fly in from local woods.
• Birds feeding on your crop will attract other birds, compounding the problem.
• The sweeter and earlier the grape, the more attractive it is to the birds.
• Even if crops are protected with netting, birds may perch on the nets and feed through them or find small holes.
Adapted from Bird Control on Grape and Tender Fruit Farms, a Factsheet published by the Ontario Ministry of Agriculture, Food and Rural Affairs, 1998
