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Providing evidence to improve practice

Individual study: Deterrent methods impractical for deterring great crested grebes Podiceps cristatus from predating on common bleak Alburnus alburnus in Lake Como, Lombardia, Italy

Published source details

Gagliardi A., Martinoli A., Preatoni D., Wauters L.A. & Tosi G. (2006) Behavioral responses of wintering great crested grebes to dissuasion experiments: implications for management. Waterbirds, 29, 105-114


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Scare birds from fish farms Bird Conservation

At four sites around Lake Como, Italy, a controlled replicated experiment (Gagliardi et al. 2006) found that none of three deterrents (gas cannon detonations, fire crackers and shooting near birds) were effective or practical in deterring great crested grebes Podiceps cristatus from areas with commercially important common bleak Alburnus alburnus shoals. Grebe behavioural response was recorded during 3-h observation periods when deterrents were or were not, in use. Cannons had little effect. Crackers and shooting caused significant behavioural changes (less time feeding, resting and preening, and more time swimming) compared to control periods, but grebe numbers were only temporarily reduced in the vicinity.