Action Synopsis: Bird Conservation About Actions

Provide supplementary food for wildfowl to increase adult survival

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

Study locations

Key messages

  • Two studies from Canada and Northern Ireland found that five species of wildfowl readily consumed supplementary food (grains and seeds).
  • Only the Canadian study assessed the physiological effects of feeding, and found that fed birds were heavier and had larger hearts or flight muscles or had more body fat than controls


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 randomised, replicated and controlled trial at Karrak Lake in Northwest Territories, Canada, (Gloutney et al. 1999) found that female lesser snow geese Chen caerulescens caerulescens and Ross’s geese C. rossii used supplementary food to different extents during incubation and showed different physiological responses to food. However, both males and females of both species were either heavier, had heavier hearts, more body fat or larger flight muscles when fed, compared to unfed controls. Differences were apparent both after laying and at the end of incubation. Between 250 g and 400 g of cracked and whole corn, durum wheat or shelled rice was provided each day.

    Study and other actions tested
  2. A study in a wetland reserve in Northern Ireland (McGeehan 2005) found that mallards Anas platyrhynchos were attracted to, and ate, ‘Wildbird Mix’ seeds provided. However, they dominated and excluded other species, so the mix was replaced with white millet seed. This was too small for mallard to eat, and so other species such as wigeon A. penelope and teal A. crecca were able to feed. The reaction of waders to the same feeding activity is discussed in ‘Provide supplementary food to increase adult survival – Waders’.

    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?

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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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