Action Synopsis: Bird Conservation About Actions

Provide supplementary food for waders to increase reproductive success

How is the evidence assessed?

Study locations

Key messages

A small controlled trial from the Netherlands found that Eurasian oystercatchers Haematopus ostralegus did not produce larger replacement eggs if provided with supplementary food, and their eggs were, in fact smaller than the first clutch, whereas control females laid larger replacement eggs.


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 small controlled trial on a saltmarsh on the island of Schiermonnikoog, The Netherlands (Jager et al. 2000) found that seven female Eurasian oystercatchers Haematopus ostralegus, following the experimental removal of their first clutch, did not produce significantly larger eggs (as part of a replacement clutch) if provided with 50 boiled mussels Mytilus edulis (averaging 46 mm long) a day, compared with control (unfed) oystercatchers (average egg volume of 41.2 cm3 for fed females, n = 7 vs. 43.4 cm3 for control females, n = 19). In addition, the replacement eggs of fed females were, on average, smaller than original eggs (by 0.9 cm3), whereas replacement eggs for control females were larger than originals (by 0.2 cm3).

    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 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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