Evaluation of two perch deterrents for starlings, blackbirds, and pigeons

Bird-aircraft collisions are costly and potentially deadly to people and wildlife. From 1990 through 2004, 57,702 bird collisions with aircraft were reported within the USA to the US Federal Aviation Administration. Approximately 82% of the strikes occur below 305 m height about ground level; therefore bird deterrents on airfields that reduce the quality of the birds’ habitat are critical to safe airport operation. One management approach is to reduce perching sites within the airport premises. We tested two anti-perching devices (BirdwireTM and BirdbloxTM) in an aviary setting. As an ancillary test, we determined which wire in a standard three-strand security array was preferred by blackbirds and starlings. Red-winged blackbirds (Agelaius phoeniceus), brown-headed cowbirds (Molothrus ater), and European starlings (Sturnus vulgaris) were deterred from sitting on a perch when anti-perching wire was installed 5 cm above the perch. These same species preferred the top wire of the three-wire security array. Red-winged blackbirds, common grackles (Quiscalus quiscula), brown-headed cowbirds, European starlings, and rock pigeons (Columba livia) were deterred from perches protected by BirdbloxTM. Because our tests were conducted in a captive situation, we recommend field testing the products to determine if bird use of airport structures may be reduced in an operational setting