Evaluation of Blackbird Damage to Sunflower and the Relationship to Producer Damage Estimates
Abstract
Sunflower producers face profit losses due to crop depredation by migrating blackbirds (Icteridae). Blackbird damage to sunflower in North Dakota is highly localized, where economic loss to some sunflower fields is severe (loss >20%), others face negligible loss (<5%). To mitigate conflict between producers and blackbirds, an understanding of severity and distribution of bird damage is essential. We investigated blackbird damage to sunflower using estimates collected in the field and estimates gathered from producers through a written survey and direct contact. Damage estimates indicate a state-wide loss of US$10.3-33.5 million. Our comparison of estimates from 2020 indicate that blackbird damage is higher when reported by producers (i.e., survey and direct contact) when compared to infield estimates. The disparity of estimates and unpredictability of bird damage warrants investigation into estimation practices by both biologists (i.e., improved field and survey methods) and farmers (e.g., yield monitors) to achieve accurate estimates of damage.