Action Synopsis: Bird Conservation About Actions

Plant cereals for whole crop silage

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

Study locations

Key messages

A replicated, controlled trial in the UK found that seed-eating birds used CBWCS fields, especially those planted with barley, more than other crops in both summer and winter. Insect-eating species used other crops and grassland more.


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 2004-2006 in northwest England (Mortimer et al. 2007) found that seed-eating songbirds and swallows and martins were more abundant on cereal (wheat and barley) fields planted in livestock areas than in grass and maize fields. In winter 2005/6, 1,390-1,564 seed-eaters were recorded on barley stubbles compared to 48 on grass fields and 406 on maize. Large insect-eating birds (thrushes) were far more abundant on grass fields in winter (2,272 birds in total, compared to 28-789 on other field types. Winter wheat and spring barley were sown in 16 trial fields, each on a separate farm in Cheshire, Staffordshire and north Shropshire. Neighbouring maize or short-term grass silage fields were monitored for comparison. Plants, invertebrates and birds were monitored on each field, in summer 2005 and winter 2005/06.

    Study and other actions tested
  2. A review of four experiments on the effects of agri-environment measures on livestock farms in the UK (Buckingham et al. 2010) found one study of CBWCS in which winter wheat planted for silage was avoided by seed-eating birds during winter, but used as much as a control spring barley crop during summer. Maize planted for silage was little used by birds in summer or winter. These results are reported in more detail by Peach et al. (2011). This study also describes the results of several other interventions, discussed in the relevant sections.

    Study and other actions tested
  3. An update of Mortimer et al. 2007 included data from winter 2004/5 (Peach et al. 2011) and found that CBWCS fields were used significantly more by farmland birds than other crop types. Each farm contained two CBWCS fields (autumn-sown wheat, 5.3 ha, and spring-sown barley, 4.4 ha), one maize field (6.1 ha) and one grass field (2.1 ha). During summer, a total of 1,535 seed-eaters and 1,901 swallows and martins were found on barley CBWCS fields, compared with 847 and 197 for wheat CBWCS fields; 441 and 95 for maize fields; and 41 and  480 for grass fields. Northern lapwing Vanellus vanellus, insect-eating species, and crows did not use CBWCS fields more than other types in summer. In winter, seed-eating species (seed-eating songbirds, Eurasian skylark Alauda arvensis, meadow pipit Anthus pratensis) used barley stubbles extensively, whilst insect-eating species used other crop stubbles more. The authors argue that CBWCS (with selectively applied herbicide, retention of over-winter stubbles and delayed harvesting) offer a practical conservation measure for seed-eating farmland birds. This study uses data from Defra report number BD1448 (Defra 2007).

    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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