Action Synopsis: Bird Conservation About Actions

Re-seed grasslands

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

Study locations

Key messages

  • One of two studies, both from the UK and investigating grazing by geese Branta spp., found that geese grazed at higher densities on grasslands that were re-seeded, compared to control or fertilised areas.
  • One study found that areas sown with clover were grazed at higher densities than those sown with grass seed.


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, controlled trial in 1984-7 on a reserve on the island of Islay, west Scotland (Percival 1993), found that more barnacle geese Branta leucopsis used wet pasture fields if they were reseeded, compared to if they were fertilised or untreated (reseeding increased dropping density by 60-135%; fertilisation by 17-42%, but not in all fields or years). The effect of reseeding declined over time, and as the overall area of rotational grassland on the reserve increased. Reseeding consisted of ploughing fields and sowing with a perennial rye-grass Lolium perenne dominated seed mix in May.

    Study and other actions tested
  2. A replicated study on an arable field on Thorny Island, in Suffolk, England, in the winters of 1992-1993 and 1993-1994 (McKay et al. 2001) found that dark-bellied brent geese Branta bernicla bernicla preferentially foraged on plots sown with white clover Trifolium repens, compared to three grass species (10-13 droppings/m2 for 12 clover plots vs. 0-5 droppings/m2 for 36 grass plots). There were no differences between grass species (perennial ryegrass, red fescue Festuca rubra or timothy Phleum pratense). Plots were established in spring 1991 and preferences were found in both years, although more geese used grass plots in 1993-1994.

    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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