Evaluation of a visual birdscarer, 'the peaceful pyramid', in Canterbury vineyards : A dissertation submitted in partial fulfillment of the requirements for the Degree of Bachelor of Science (Honours) at Lincoln University

Abstract

The effectiveness of a visual birdscarer, the Peaceful Pyramid ® ('the pyramid' ), relative to a much-cheaper eye-spot balloon was investigated in three field experiments in vineyards at Lincoln and Dunsandel, Canterbury, New Zealand, between February and July 1999. The pyramid is a recently-developed scaring device that reflects light to deter birds. Birds habituated to the pyramid within 1-2 days and the device produced no significant reduction in bird damage to grapes after 10 hours of exposure in Lincoln vineyard. The eye-spot balloon significantly reduced damage by 6 times compared with the pyramid, although birds habituated to it within 2-3 days. If, however, the location of the devices was changed every 6 days, the balloon significantly reduced starling (Sturnus vulgar is) damage to Riesling grapes within a 35 X 10m² plot compared with the pyramid and control plots at Dunsandel vineyard. Nevertheless, total damage levels in the pyramid and the balloon plots reached 83.8% and 74.9% after 24 days, respectively. Thus, both devices failed to provide any useful reduction in grape . A significant correlation between bird damage and grape sugar levels was observed. Overall, the $10 eye-spot balloon was slightly more effective than the $680 pyramid in deterring birds. This highlights the importance of quantitative testing of birdscarer effectiveness under field conditions. The need for development of rigorous methodology in evaluating the effectiveness of scaring devices in the field is discussed.