More and more California vineyards are enlisting birds of prey to help thwart starlings that clove to feed on the growing grapes. Though many people admire their giant swooping formations, starlings are an invasive species in America. They were first imported from Europe in the 1800s and have experienced a population explosion. The 200 million starlings in the USA cause an estimated $1.6 billion in damage to fruit and grain crops annually.
Vineyards began employing trained falcon experts as a more cost-effective and environmentally friendly solution to the ineffective plastic netting and noise-polluting speakers traditionally used in the past.
Chad Boardman, a vineyard manager for Gallo, says his company opts for falcons in their fields not just because of sustainability but because the raptors save Gallo a good deal of money. “They’re beautiful looking birds, and it’s great to watch them fly, but also, because of them, we know every year that we’re not going to lose grapes to the birds,” Boardman explains.
One of the falcon experts working the Gallo vineyards is Kenley Christensen, who flies his flock of raptors over one of the company’s properties for about eight weeks a year. Christensen, who got his first falcon when he was just a tween, says he’s been with Gallo for about 14 years. Each year, he rolls up to the vineyards in his trailer, 15 or so birds in tow, right around the start of the veraison (when the grapes begin to ripen) in early August.
“The starlings are most interested in the sugar in the grape juice and not the fruit,” Christensen explains. “The starlings are trying to build up their fat reserves for the winter so they don’t have to burn many calories to keep warm. It’s just like us: We eat more food during the winter than in the summer because we want to keep warm.”
Christensen and his bird pals will stay in the vineyard until the end of harvest, which usually comes right around the middle of October. Each day of that stay, Christensen says, he’ll spend about eight or nine hours roaming the vineyard with a falcon. “As soon as the sun comes up, we’ll take the hood off of one of the birds and put them on top of the truck,” Christensen says. “We’ll drive around the vineyard with the bird flying above the truck, and when we see a group of starlings, we’ll call him into that group of starlings by throwing a lure out. That excites the starlings because they don’t want to be chased by a falcon.”
Falcon owners and the vineyards that employ them aren’t trying to kill starlings. Christensen says he keeps his birds well-fed enough that they shouldn’t try to hurt the smaller birds. Instead, Christensen says, his goal is to condition the starlings to think there’s always a predator in the vineyard. He explains, “The analogy we like to use is that if you go to the beach to swim, but you see a shark the first couple of days you hit the beach, you’re not going to continue going to that same beach. You’ll move and go somewhere else to swim because you think there’s a shark at that other beach. That’s what we’re trying to do with the starlings. We’re trying to persuade them to go somewhere else to find their food.”
It takes about two weeks for a particular flock of starlings to figure out that there will always be a predator in a particular area. When they do, they inevitably move on to another feeding location. Still, Christensen says, he has to stay in the vineyard the whole time the grapes are ripe because new groups of starlings are continuously coming in and out of the area depending on the time of year.
According to Christensen, falcons are the perfect birds for the job because they’re aerial predators. Unlike eagles or hawks, who hunt squirrels, rabbits, mice, or other small mammals, falcons are built to hunt down other flying birds. Christensen always keeps plenty of falcon-friendly tidbits, like quail, on hand when he’s flying his birds, saying, “When they come in, they always get a little bit of food so that they know that they’re gonna eat better if they come to me.”
Vineyard falcons like Christensen’s team are typically on a pretty regimented schedule. Each bird has a purpose and a time of day when it’s trained to fly. Christensen says he flies what is called “pursuit birds” in the morning, and in the afternoon, he uses a different set of birds that are better equipped to soar on the thermal currents up 1000 to 3000 feet in the air. “You’ll see them get into a routine where they know exactly when it’s their time to fly,” says Christensen. “The birds will set up a territory and go there each day. One of the falcons I have has flown the same territory for nine years. He’ll fly that territory, trying to keep everything out of that area.”
The higher the falcon is, the more area it can typically cover. Christensen says that, in general, he’s using his team of birds to try to keep about a mile radius around the vineyard cleared, just so that no starlings start creeping in on the edges.
Starlings can do immense damage to a crop of grapes. It’s not just that they eat the fruit; Starlings can also peck the grapes, allowing the juice to run out of the grapes and onto other nearby fruit, causing mold and rot. The sugary juice can also attract swarms of bees, making for a messy and complicated harvest.
There are other economic incentives for using the birds, particularly in comparison to the cost of using plastic netting to cover a vineyard. Christensen estimates that his services cost about a third of what netting a crop would cost and also makes growers a bit more nimble when harvest time rolls around. “If a winemaker decides to harvest a different block than what they’d originally thought, you have to pay the labor to re-net the block you took down and pay the labor to take the nets off the next block,” he explains. “With falcons, there are no nets; there’s no labor, there’s nothing. It’s just an open vineyard. So if they decide to pick block one and then change their mind to pick block 16, they don’t have to wait and have somebody come in and take the nets off. They just can move everything down to block 16 and pick that instead.”
It’s worth noting that while falconry itself is a centuries-old sport, using birds in vineyards is a relatively new development. Christensen is quick to add that mainstream business owners are only really beginning to understand falcons’ potential. “We can use these birds to help outcrops and dairies and feedlots,” he says. “We can fly falcons over refineries and shopping centers.
There are a lot of different businesses that use falcons, but not a lot of people notice. They just know that the starlings and seagulls aren’t around to bother them anymore.
So next time you see a falcon, give it a nod of thanks for keeping your wine safe and affordable.