Wildlife Damage Management, Internet Center for


Date of this Version

April 1991


Abstract: The effectiveness of 74-kg, white, twisted nylon twine was evaluated for deterring rock doves (Columba livia) from landing on ledges at Colorado State University's Hughes Stadium in a controlled experiment during 1990. One, 2, and 3 lines were stretched 8 cm in front and 12 cm above (1 line), 8 and 18 cm above (2 lines), and 5, 12, and 18 cm above (3 lines) the ledges. The proportion of successful landings to attempted landings was reduced from 0.99 (0 lines) to 0.23 (1 line), 0.13 (2 lines), and 0.10 (3 lines). The number of pretreatment landings per ledge per hour X = 24.1) was reduced to an average of 11.7, 7.7, and 5.6 landings per hour with 1, 2, and 3 lines, respectively. The proportion of doves that successfully landed increased from weekends 1 through 4 and from days 1 through 4 within weekends indicating that some rock doves learned to circumvent the lines. Rock doves likely had a greater incentive to land on ledges on our study site compared to most other sites because large roosting and nesting areas were found behind 3 of the ledges. With a lower incentive to land, nylon lines may be even more effective for deterring landings by rock doves at other sites.