Date of this Version
The surfactant PA-14, registered with the U.S. Environmental Protection Agency (EPA) in 1973 by the federal Animal Damage Control (ADC) program, was used for 19 years (1974-1992) for lethal control of roosting blackbirds (Icterinae) and European starlings (Sturnus vulgaris) in the United States. In 1992, the ADC program withdrew the registration of PA-14 because of costs required to provide additional EPA-requested data. There were 83 roosts encompassing 178 ha treated with 33,300 L of PA-14 from 1974-1992. An estimated 38.2 million birds (48% common grackles [Quiscalus quiscula], 30% European starlings, 13% red-winged blackbirds [Agelaius phoeniceus], and 9% brownheaded cowbirds [Molothrus ater] were killed, an average of 2.0 million/year. The annual kill represented ≤ 1.3% of the national winter population of blackbirds and starlings. We found no evidence using North American Breeding Bird Survey (BBS) data that PA-14 applications caused declines in regional breeding populations. Furthermore, there was no evidence of secondary poisoning or other adverse environmental effects from PA-14 applications. If regional population management of blackbirds and starlings is to be implemented to reduce agricultural damage or conflicts with native songbirds, new approaches, such as reproductive control, are needed because PA-14 alone will not be adequate. However, PA-14 could have a role in such regional programs in addition to solving localized roost problems. PA-14 was a useful management tool safely applied in human-populated areas (where most roost problems occur); its reregistration should be considered as part of an integrated management program for blackbirds and starlings.