Individual study: A review of the effectiveness of attempts to reduce predation by fish-eating birds
Draulans D. (1987) The effectiveness of attempts to reduce predation by fish-eating birds: a review. Biological Conservation, 41, 219-232
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
A 1987 literature review (Draulans 1987) found that there was little evidence that scaring devices at fish farms succeeded in increasing fish stocks/reducing losses. Devices could be classified as visual (scarecrows, flags, reflectors, lights, model etc), acoustic (gun shots, firecrackers and gas cannons) or biological (recordings of distress calls etc). Black-crowned night herons Nycticorax nycticorax were deterred by distress calls but only close to the speaker and no data are presented to support any positive effects on fish stocks. The use of dead birds, model predators and dogs is reported by several authors as almost completely ineffectual. Trained raptors seemed effective but expensive.