Wildlife Damage Management, Internet Center for
Date of this Version
2-9-1997
Abstract
During the winters of 1994-95 and 1995-96, unusually large numbers of diving ducks were observed on baitfish facilities in Arkansas. Historically, lesser scaup (Aythya affinis) inhabited baitfish ponds with little reported impact on minnow production, and thus little attention was paid to the birds. Unfortunately, minnow crops in the spring of 1995 fell short of expectations and immediate attention became focused on the role lesser scaup may have had on that minnow shortage. Subsequently, lesser scaup were collected from baitfish facilities in an effort to determine their effect on commercial fish farms. Two hundred and twenty-three lesser scaup were analyzed and esophageal/gizzard contents were examined. Seventy-two percent (n = 161) contained at least one food item, with 28% (n = 45) containing minnows that were commonly raised by baitfish farmers. Other food items consisted of snails, freshwater shrimp, insects, insect larvae, and vegetation. For ducks containing minnows, mean number of golden shiners and goldfish consumed per duck was 2.90 and 8.72 with mean total length being 6.22 cm and 3.95 cm, respectively. Mean loss estimates for golden shiners was $0.04 per bird per feeding, while goldfish was $0.12 per bird per feeding.