Action Synopsis: Bird Conservation About Actions

Provide artificial nesting sites for wildfowl using artificial/floating islands

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

Study locations

Key messages

  • Two studies from North America found that a variety of wildfowl used artificial islands and floating rafts, and had high (70–80%) nesting success.
  • A replicated study from across the UK found that wildfowl preferentially nested on well vegetated islands, compared to bare ones.


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 replicated study on two marshland sites in Pennsylvania, USA, in 1976-8 (Brenner & Mondok 1979), found that 56% of 20-34 artificial nesting rafts were used by wildfowl, with mallards Anas platyrhynchos using up to 50% of nest rafts, blue-winged teal A. discors up to 9% and Canada geese Branta canadensis up to 5%. Hatching success on rafts was 80%. Rafts had a wooden frame and Styrofoam centre, an arching roof of wire mesh with two anchors of different weights allowing the raft to float up and down with changing water levels. The authors estimate the cost at $0.85/duckling (in 1979 dollars).

    Study and other actions tested
  2. A replicated study at seven prairieland impoundments in Alberta, Canada (Giroux 1981), found that in 1976-8, 1,349 nests from 13 species of wildfowl were found on 75 artificial islands (75 islands searched in 1976-7 and 53 in 1978). Ducks (12 species) nested at densities of 1.8-29.1 nests/ha, with 43-59% success. Canada geese Branta canadensis nested at densities of 0.2-7.1 nests/ha, with 70% success (144 nests). Islands were most productive when small, far from shore and with high vegetation cover. Islands were created before flooding of the impoundments by raising some areas about to be flooded or isolating peninsulas with ditches and were between 0.13 ha and 6.6 ha in size.

    Study and other actions tested
  3. A replicated 1992 study of the use of artificial islands and floating platforms in 17 wetland nature reserves across the UK (Burgess & Hirons 1992) found that 11 species of wildfowl nested with greater frequency on well vegetated islands and platforms than on sparsely vegetated ones. This pattern was strongest at inland northern reserves, where all 11 species used well-vegetated sites, but none used sparsely covered ones. At coastal sites and southern reserves the pattern was weaker, but well-vegetated sites were always used by more species. The species studied were eight species of ducks, Canada geese Branta canadensis, feral greylag geese Anser anser and mute swans Cygnus olor. At four sites, the provision of vegetated islands or rafts resulted in the establishment of new populations of five duck species. The review also examines island and platform use by grebes, divers, ground-nesting seabirds, waders and rails.

    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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