Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Capture and relocation of grey herons Ardea cinerea proves an inefficient and ineffective method of reducing predation at a fish farm in Belgium

Published source details

van Vessem J., Draulans D. & De Bont A. F. (1985) The effects of killing and removal on the abundance of grey herons at fish farms. Proceedings of the International Union of Game Biologists 17th Congress, 337-343

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

Translocate birds away from fish farms Bird Conservation

A study in Belgium found that capturing grey herons Ardea cinerea (using clap nets) at a fish farm and releasing them at various distances away (Van Vessem et al. 1985) did not appear to reduce heron abundance. Catching herons was very time-consuming (a maximum of four, but usually 1-2 caught each day). Some birds released 30 to 80 km returned within a month; one released 150 km away reappeared the following winter. Numbers relocated were too low to reduce heron abundance and relocation was considered ineffective.