Estimation of Effective Area of Bird Scarers

Abstract

I modified Nakamura and Matsuoka's (1987) model for the feeding of birds in a field to determine the effective area of scarers. In experiments to determine the effectiveness of scarers I used different visual and acoustic stimuli on rufous turtle doves (Streptopelia orientalis) in a flight cage. Effective area for each scarer was based on the area over which bird staying rate was decreased. A mannequin had a larger effective area than did a stuffed crow or Gayla kite® (Gayla Industries, Houston, Tex.). Although the presentation of a crow's call had little effective area, the simultaneous presentation of a stuffed crow with a crow's call resulted in a large effective area.