Birds Associated with Grapes In Erie County, Pennsylvania

Abstract

Observations were made of birds in wine grape vineyards near North East, Erie County, Pennsylvania, from early September to October in 1973 and 1974. Birds were trapped with fine-mesh nylon netting. Crop and gizzard contents of selected specimens were examined.

Although 17 bird species were trapped in the vineyards, only 5 had grapes in their crops or gizzards: American Robin (Turdis migratorius), Cedar Waxwing (Bombycilla dedrorum), Common Starling (Sturnus vulgaris), Gray Catbird (Dumetella carolinensis), and Swainson's Thrush (Catharus ustulata). One specimen of Common Cardinal (Richmondena cardinalis), not dissected, was found to have anal feathers stained purple, indicating grape feeding. Two specimens of Song Sparrow (Melospize melodia) had grape seeds in their crops or gizzards but no evidence of grape berry skins. Other birds trapped in the vineyards were Brown-Headed Cowbird (Malothrus ater), Common Grackle (Quiscalus quiscula), Scarlet Tanager (Piranga olivacea), Dark-Eyed Junco (Junco hyemalis), sparrows (Spizella passerina, Zonotrichia albicollis, and Passerculus sandwichensis), House Sparrow (Passer domesticus), and warblers (Wilsonia pusilla and Dendroica coronata). Other birds observed in the vineyards, but not trapped, were the common Flicker (Colaptes auratus) and Brown Thrasher (Toxostoma rufum).

Bird depredation in Pennsylvania vineyards parallels that of wine grape production in the state. Crop losses from birds have occurred in many vineyards in Pennsylvania where grapes are grown commercially, primarily in Adams, Bucks, Erie, Franklin, and Lancaster counties.

Bird depredation occurs from mid-August to early October, depending on the wine grape cultivar and degree of ripeness. Nearly all grape cultivars are attacked to some extent. Damage from birds has been greatest, however, on the cvs. Aurora, Cascade, Chancellor, DeChaunac, Leon Millot, and Marechal Foch.

Purposes of this study were to identify bird species commonly found in selected vineyards in Erie County in 1973 and 1974, to examine crop and gizzard contents of selected specimens to determine which species were actually eating grapes, and to compile an initial documented list of birds that damage grapes in Pennsylvania.