European starling preferences for bait substrates used in DRC-1339 applications

Additional bait substrates for the avicide, DRC-1339 Concentrate (3-chloro-4-methylaniline hydrochloride), could provide USDA/Wildlife Services with more flexibility when managing nuisance populations of European starlings (Sturnus vulgaris) at livestock facilities. From January 11 to 21, 2008, we conducted 11 2-choice preference tests with 6 bait types at a feedlot in central Kansas. The baits included cracked corn mixed with lard (2 concentrations), 2 forms of distiller’s grain (wet powder and pellets), 2 types of livestock feed (calf-starter pellet and sweet-feed mix), and a custom-produced poultry pellet (carrier pellet) made by USDA specifically for baiting starlings. We evaluated bait preference using 95% confidence intervals of mean differences in feeding rates among 4 cages of starlings with 6 starlings per cage. Starlings preferred the carrier pellets. Contemporaneous with the cage tests, we offered the same baits to free-ranging starlings at open-feeding platforms positioned within the feedlot. Free-ranging starlings also favored carrier pellets over other baits. Use of carrier pellets at livestock facilities where starlings have numerous food sources may be more cost-efficient than less-expensive baits (e.g., cracked corn or distiller’s grain) because of its higher acceptance by free-ranging starlings.