Action Synopsis: Bird Conservation About Actions

Remove or control predators to enhance bird populations and communities

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms
    not assessed

Key messages

  • A meta-analysis and a systematic review both found that reproductive success increased with predator removal, but their exact findings differed.
  • The meta-analysis found that post-breeding population size increased, whilst the systematic review found that this was true on mainlands, but not islands and that breeding populations also increased.


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 meta-analysis of 20 published studies (Côté & Sutherland 1997) showed that predator removal had a large, positive effect on hatching success – with removal areas showing higher hatching success on average than 75% of control areas – and led to a significant increase in post-breeding population size (i.e. autumn density), although no significant impact was detected on breeding population size.

    Study and other actions tested
  2. A 2010 systematic review (Smith et al. 2010) found that removing predators tended to lead to increased reproductive success (hatching and fledging success) and breeding populations in birds. On mainlands, but not islands, predator removal also tended to increase post-breeding population size. Whether predators were native or not, the population trend of the bird population and whether the species was migratory or a game species did not affect responses to predator removal.

    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

All the journals searched for all synopses

Bird Conservation

This Action forms part of the Action Synopsis:

Bird Conservation
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What Works in Conservation

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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