Action: Create beetle banks
- A small UK study found that a site with beetle banks had increasing populations of rare or declining species, although several other interventions were used on this site. A literature review from the UK found that grey partridge Perdix perdix populations were far larger on sites with beetle banks and other interventions than on other farms. Two replicated studies from the UK also investigated population-level effects: one found that no bird species were strongly associated with beetle banks; the second found no relationship between beetle banks and grey partridge population density trends.
- A UK literature review found that two bird species nested in beetle banks and that some species were more likely to forage in them than others. A study in the UK found that one of two species used beetle banks more than expected. The other used them less than other agri-environment options.
Beetle banks are grassy mounds, about 2 m wide, that run across the middle of large arable fields. They are intended to provide habitat, especially during winter, for predatory insects such as beetles and spiders and therefore could also provide foraging habitats for birds.
Supporting evidence from individual studies
A 2000 literature review from the UK (Aebischer et al. 2000) found that the populations of grey partridge Perdix perdix was 600% higher on farms with conservation measures aimed at partridges in place, compared to farms without these measures. Measures included the provision of conservation headlands, planting cover crops, using set-aside and creating beetle banks.
A study of different set-aside crops at Allerton Research and Educational Trust Loddington farm, Leicestershire, (Murray et al. 2002) found that Eurasian skylarks Alauda arvensis, but not yellowhammer Emberiza citrinella used beetle banks more than expected compared to availability. Skylarks used them significantly more than unmanaged set-aside, broad-leaved crops and other habitats, while yellowhammers used them significantly less than cereal and set-aside with ‘wild bird cover’. Field margin and midfield set-aside strips were sown with kale-based and cereal-based mixtures for ‘wild bird cover’, and ‘beetle banks’. Other habitat types were: unmanaged set-aside, cereal (wheat, barley), broad-leaved crop (beans, rape) and ‘other’ habitats. Thirteen skylark and 15 yellowhammer nests with chicks between 3-10 days old were observed. Foraging habitat used by the adults was recorded for 90 minutes during three periods of the day. This study is also discussed in ‘Plant wild bird seed /cover and Provide (or retain) set-aside areas in farmland’.
A small replicated study from May-June in 1992-8 in Leicestershire, England (Stoate 2002), found that the abundance of nationally declining songbirds and species of conservation concern significantly increased on a 3 km2 site where beetle banks were created (alongside several other interventions), although there was no overall difference in bird abundance, species richness or diversity between the experimental and three control sites. Numbers of nationally declining species rose by 102% (except for Eurasian skylark Alauda arvensis and yellowhammer Emberiza citronella). Nationally stable species rose (insignificantly) by 47% (eight species increased, four decreased). The other interventions employed were: ‘Manage hedges to benefit wildlife’, ‘Plant nectar flower mixture/wildflower strips’, ‘Plant wild bird seed cover strips’, ‘Provide supplementary food’, ‘Control predators’ and ‘Reduce pesticide or herbicide use generally’.
A replicated study in 1999 and 2003 on 256 arable and pastoral fields across 84 farms in East Anglia and the West Midlands, England (Stevens & Bradbury 2006), found that none of 12 species of farmland bird were strongly associated (either positively or negatively) with beetle banks. The species analysed were skylark Alauda arvensis, corn bunting Miliaria calandra, lapwing Vanellus vanellus, yellow wagtail Motacilla flava, chaffinch Fringilla coelebs, dunnock Prunella modularis, greenfinch Carduelis chloris, linnet C. cannabina, reed bunting Emberiza schoeniclus, tree sparrow Passer montanus, whitethroat Sylvia communis and yellowhammer E. citrinella. This study describes several other interventions, discussed in ‘Leave headlands in fields unsprayed (conservation headlands)’; ‘Leave uncropped, cultivated margins or plots, including lapwing and stone curlew plots’; ‘Leave overwinter stubbles’; ‘Plant grass buffer strips/margins around arable or pasture fields’; ‘Create uncultivated margins around intensive arable or pasture fields’; ‘Plant wild bird seed or cover mixture’; ‘Provide or retain set-aside areas in farmland’; ‘Pay farmers to cover the costs of conservation measures’ and ‘Reduce pesticide or herbicide use generally’.
A 2007 UK literature review (Stoate & Moorcroft 2007) describes studies that found grey partridge Perdix perdix and Eurasian skylarks Alauda arvensis nesting in beetle banks. One study also found that skylarks were more likely than yellowhammers Emberiza citrinella to forage in beetle banks. This study is also discussed in ‘Leave uncropped, cultivated margins or plots, including lapwing and stone curlew plots’, ‘Plant grass buffer strips/margins around arable or pasture fields’ and ‘Create skylark plots’.
A replicated site comparison study on 1,031 agricultural sites across England in 2004-8 (Ewald et al. 2010) found that grey partridge Perdix perdix overwinter survival was significantly and positively correlated with the presence of beetle banks in 2007-8. Across all years there was a positive relationship with the ratio of young to old birds. There were no relationships with brood size or year-on-year density changes. This study describes the effects of several other interventions, discussed in the relevant sections.
- Aebischer N.J., Green R.E. & Evans A.D. (2000) From science to recovery: four case studies of how research has been translated into conservation action in the UK. Pages 140-150 in: J.A. Vickery, P.V. Grice, A.D. Evans & N.J. Aebischer (eds.) The Ecology and Conservation of Lowland Farmland Birds. British Ornithologists' Union, Tring.
- Murray K.A., Wilcox A. & Stoate C. (2002) A simultaneous assessment of farmland habitat use by breeding skylarks and yellowhammers. Aspects of Applied Biology, 67, 121-127
- Stoate C. (2002) Multifunctional use of a natural resource on farmland: wild pheasant (Phasianus colchicus) management and the conservation of farmland birds. Biodiversity and Conservation, 11, 561-573
- Stevens D.K. & Bradbury R.B. (2006) Effects of the Arable Stewardship Pilot Scheme on breeding birds at field and farm-scales. Agriculture, Ecosystems & Environment, 112, 283-290
- Stoate C. & Moorcroft D. (2007) Research-based conservation at the farm scale: development and assessment of agri-environment scheme options. Aspects of Applied Biology, 81, 161-168
- Ewald J.A., Aebischer N.J., Richardson S.M., Grice P.V. & Cooke A.I. (2010) The effect of agri-environment schemes on grey partridges at the farm level in England. Agriculture, Ecosystems & Environment, 138, 55-63