Grower practices for blackbird control in wild rice in California
We surveyed 29 wild rice growers, representing 96% of the California acreage grown in 1993, to determine current practices for blackbird damage control. Twenty-seven growers (93%) had blackbird damage. The period of greatest damage and most intensive control was July through September. Red-winged blackbirds (Agelaius phoeniceus) most frequently caused damage, but three other species of blackbirds and the European starling (Sturnus vulgaris) were also identified. Most growers (72%) reported 1 to 10% yield loss. Average loss ranged from $121 to $309/ha, and from $14,530 to $32,061/grower. Most growers (97%) attempted to control blackbirds for an average of 3.5 months during the growing season, relying primarily on shotguns, propane cannons, shellcrackers or bird bombs, and patrols. Growers in northeastern California tended to rate these techniques as more effective than growers in the Sacramento Valley, possibly due to the larger field sizes in the Valley. Average effectiveness ratings for all techniques indicated little better than slight control for the techniques used, suggesting grower dissatisfaction with the available techniques. Average cost for control averaged $86.21/ha, which was among the highest costs for any single aspect of wild rice production.