(A falcon on patrol; Image: Sara Kross)
Vineyards often lose thousands of dollars worth of grapes each year due to bird foraging, but a team of researchers supports a clever solution to the ongoing problem: Bring in a bigger bird.
The presence of a single falcon can "potentially result in savings of $234/ha for the Sauvignon Blanc variety of grapes and $326/ha for Pinot Noir variety of grapes," wrote Sara Kross and her team in the journal Conservation Biology.
For the study, Kross and colleagues Jason Tylianakis and Ximena Nelson, all from the University of Canterbury's School of Biological Sciences, examined whether introduction to vineyards of the New Zealand Falcon (Falco novaeseelandiae), a species listed as threatened by the New Zealand Department of Conservation, affected the abundance of four species of passerine birds (blackbirds, song thrushes, starlings and silvereyes) that are considered to be vineyard pests or affected the amount of economic loss due to grape damage.
Blackbirds, song thrushes and starlings all eat whole grapes and even entire bunches. Silvereyes poke holes out of grapes. It's hard to blame these birds. They're hungry and near row after row of delicious, tempting and colorful fruit. What bird could possibly resist such an eye-catching banquet?
The answer is a bird that serves as prey for falcons.
In some cases, the avian foragers were simply scared away, and for good reason. The falcons likely ate some of the other birds, the researchers suspect. That's something a lifeless scarecrow could never achieve.
Kross and her team report that "the introduction of falcons to vineyards was associated with a significant decrease in the abundance of introduced passerines and with a 95 percent reduction in the number of grapes removed relative to vineyards without falcons.
Falcon presence was not associated with a change in the number of silvereyes, but there was a 55 percent reduction in the number of grapes pecked in vineyards with falcons."
Falcon patrols are already being used worldwide. For example, check out how falcons are guarding one Sonoma County, CA, vineyard. These trained birds of prey are doing what nature intended. As such, they are preventing vineyards from using pesticides and other less desirable "pest" prevention methods.
So the next time you raise a glass of Sauvignon Blanc, Pinot Noir, or other wine, consider toasting to falcons, who could have helped to save the grapes used to make your vino.