By Alice Wise

In September, vineyard managers relax after a long season of early mornings and seven-day work weeks. They put up their feet and watch as the grapes develop rich colors, heady aromas and delectable flavors. Although they savor this brief hiatus, there's still plenty of work to do. Equipment must be cleaned and repaired. Preparations for harvest are taking place. Weather is a constant worry as one good autumn storm can turn a promising season into a depressing harvest.

Fall also signals the start of the battle to keep wildlife from devouring the crop.

The two biggest wildlife concerns for vineyards are birds and deer. While other animals -- mainly rabbits, groundhogs and raccoons -- can be troublesome, their collective impact pales in comparison to the damage wrought by birds and deer.

Birds are not an issue until August, when grapes start to soften, lose acidity and accumulate sugar. Often the weather is dry at this time of year, meaning birds are especially interested in the moisture-laden berries.

Besides crop loss (species such as robins pluck whole berries), many smaller species, such as finches, peck at the fruit. This renders the berries susceptible to various nasty cluster rots, which can become very ugly.

Consequently, minimizing bird damage is a major goal of vineyard managers. Such visual scare devices as balloons, reflective tape and kites are a waste of money. Auditory methods -- recordings of bird distress calls, propane cannons and the like -- have had only limited success. Exclusionary netting is the only truly effective option.

Most vineyards use a 17-foot-wide, 5/8" mesh net draped over the row. It's pricey -- around $800 per acre for materials alone -- and the latest application device runs an additional $10,000. Factor in labor and it's easy to see why bird netting is a hard cost for vineyards to swallow.

Just as quickly as humans devise deterrents, our feathered friends figure out ways around them. The ever-adaptable local birds have learned to hover and peck clusters through the nets. To address this issue, we at Cornell, along with a local grower, are testing a new, finer-mesh net that may circumvent hover-and-peck feeding. The catch? It runs about $3,000 per acre and, although the cost would be prorated over many years, such an expense would be difficult for a small business.

Depredation by deer has also increased dramatically over the last five years. A population boom, reduced hunting and increased suburban sprawl, which has concentrated the deer population, are contributing factors. Deer like to nibble on tender shoot tips and chomp on clusters. A family group can devour a row of grapes over a weekend.

Bird nets are not a deterrent to deer. The only recourse is to fence the perimeter of the vineyard. There are many types of protective fencing, including woven-mesh, heavy-duty bird netting designed specifically to deter deer, and electric fencing. All are quite expensive. Electric fencing usually is the most economical, but it's the high-maintenance option.

As you drive through wine country, expect to see an abundance of bird netting and increasing amounts of deer fence. Though most of us appreciate wildlife, we wish they'd leave our vines and grapes alone.

Alice Wise is the educator/viticulturist at Cornell Cooperative Extension of Suffolk County, LI Horti-cultural Research and Extension Center in Riverhead.