Battle of the birds begins in Lewes

It's late summer in Lewes. The annual battle against the birds is on.

Mechanical bird squawkers and air cannons boom to scare birds away from the sweet nectar of grapes growing at Nassau Valley Vineyards.

Who wins the fight varies from year to year. This year, the birds have had the upper hand, says winemaker Mike Reese.

But even with the avian onslaught, Reese said the 2016 harvest has been a successful one thanks to great grape-growing weather.

Birds – especially blackbirds and robins – almost picked clean small sections of chardonnay and merlot grapes on the 6 acres of vines. Reese said it's usually starlings that invade the vineyards, but blackbirds took over this year. Ironically, merlot means little blackbird in French.

Birds are attracted to the grapes slightly before they ripen, a few weeks before they are picked – just as color starts to appear. That's when the sound of air cannons and squawkers fills the skies around the vineyards, startling humans as well as birds.

Reese said it appears there comes a time when birds begin to adapt to the noise.

A few days before the Sept. 14 merlot harvest – in an effort to save as many grapes as possible – vineyards staff put up bird wire to scare birds away from the vines. The metallic wire whips in the breeze, creating shiny color and a whistling sound that frightens the birds. “It helped to some degree,” Reese said.

Reese theorizes two factors led to an onslaught of birds this year – dry conditions and the crops planted near the vineyards. “Birds want the liquid in the grapes when it's dry,” he said.

In addition, he said crop rotation seems to be a factor in the loss of grapes to bird invaders. He said when local farmers plant corn, birds are drawn away from the vineyards to feed on bugs. But when it's soybeans, birds tend to feast on grapes. Starlings remove entire grapes; robins peck at them.

The fight against birds it not limited to Nassau Valley. Vineyards throughout the world use various methods to deter birds. Nothing – not even netting – appears to be 100 percent effective. Experts say a combination of noise deterrents and netting gives wine growers the best fighting chance against birds.

Reese said they are trying everything possible to stay away from applying netting. “It's expensive and takes a lot of manpower. That would be a last resort,” he said.

In a Penn State University Extension Service website post, Mark Chien wrote timing is critical when it comes to noise making. Equipment must be in place before birds arrive and start feeding, because once birds identity the vines as a food source, it's hard to keep them away.

Experts say once a feeding pattern has been established, the same birds will return to the area year after year, and the sweeter the grape, the more birds are attracted to it.

It seems that birds are attracted to grapes for the same reasons humans are – color and taste.