Action Synopsis: Bird Conservation About Actions

Control predators not on islands for seabirds

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

Study locations

Key messages


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 before-and-after study at a common tern Sterna hirundo colony in eastern Canada (Guillemette & Brousseau 2001) found that fledging success was higher in 1994 when chick-predating gulls (four herring gulls Larus argentatus and one great black-backed gull Larus marinus) were selectively shot, compared with 1993 and 1995, when no gulls were culled (16% of 115 eggs fledged vs. no chicks fledging from 165 eggs).

    Study and other actions tested
  2. A before-and-after study at three sites in northern North Island, New Zealand (Wilson & Hansen), found that the population of New Zealand fairy terns Sterna nereis davisae increased from a low of five breeding pairs in 1987 and an annual decline of 1.5% to between 35 and 40 individuals in 2005 and an annual increase of 1.4%, following the continual trapping of introduced mammalian predators (feral cats Felis catus, hedgehogs Erinaceus europaeus, stoats Mustela erminia, ferrets M. putorius, weasels M. nivalis, Australian brush-tailed possums Trichosurus vulpecula and rats Rattus spp.) from 1992 onwards. On average 100 hedgehogs and 12 cats were trapped each year.

    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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