Action Synopsis: Bird Conservation About Actions

Translocate birds away from fish farms

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

A study from the USA cited in a review found that translocating birds away from a fish farm appeared to reduce the number of birds at the farm. A study from Belgium found that translocating herons did not seem to be an effective way to reduce bird numbers at fish farms.


About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A study cited in Mott 1978, effectively reduced a population of green herons Butorides virescens feeding at a fish hatchery in USA, by catching and releasing them 40 km away. No details are given regards the time period over which the reduced population level was maintained or the effort needed to catch the birds. The effects on fish farm productivity were not measured.

    Study and other actions tested
  2. 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.

    Study and other actions tested
Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.


Where has this evidence come from?

List of journals searched by synopsis

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Bird Conservation

This Action forms part of the Action Synopsis:

Bird Conservation
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What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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