The 4-aminopyridine (or 4-AP) is an avian frightening agent. It is an active ingredient in formulas where it is presented to birds as mixed grain or corn bait. After ingesting the bait birds produce distress calls that can disperse flocks of the same species from an area. Birds that have consumed bait with 4-AP usually die.
A study undertaken in North Dakota, USA, evaluated Avitrol ® FC Corn Chops-99S (AFCC-99S) containing 4-AP for its effect in reducing sunflower seed losses to red-winged blackbirds (Agelaius phoeniceus) and yellow-headed blackbirds (Xanthocephalus xanthocephalus). The relative risk of seed losses in treatment fields was lower than in the control (RR = 0.42) over a 6-day trial. In a study undertaken in Connecticut (Conover 1984), corn yield losses caused by red-winged blackbirds and common grackles (Quiscalus quiscula) were 39% lower in treatment fields over a 3-year study period. The relative risk of damage to crop ears was RR = 0.72 in comparison to untreated fields.
