Action: Create skylark plots for bird conservation
- A before-and-after study found an increase in Eurasian skylark Alauda arvensis population on a farm after the creation of skylark plots; a replicated, controlled study from the UK found higher densities of skylarks on fields with plots, compared to those without. No other studies investigated population-level effects.
- Two UK studies, one replicated and controlled, found that skylark productivity was higher in plots or in fields with plots than in controls. One replicated and controlled study from Switzerland found no differences in productivity between territories that included plots and those that did not.
- Two replicated studies (one controlled) from Denmark and Switzerland found that skylark plots were used by skylarks more than expected. A replicated and controlled study from the UK found that seed-eating songbirds did not use skylark plots more than surrounding crops.
Eurasian skylarks Alauda arvensis require short vegetation to nest in and skylark plots are small (usually 4–16 m2) undrilled patches within cereal fields that provide this, with little impact on overall yield. They are similar to lapwing plots (see above) but much smaller.
Supporting evidence from individual studies
A replicated study from April-May in 1990-3 in five spring-sown barley fields in eastern Jutland, Denmark (Odderskær et al. 1997) found that Eurasian skylarks Alauda arvensis used unsown plots in the fields significantly more than expected by an even distribution across the landscape. Radio-tracked birds were observed more in tramlines and unsown plots and mean faecal density was significantly higher in unsown areas than in crops (1.4 droppings/ha vs. 0.1). One 22 ha field with 100, 40 m2 plots had higher densities of skylarks than four fields with an average of seven plots/ha, each of 7 m2.
A replicated, controlled study from April-August in 2002-3 in 15 sites in northern and eastern England (Morris et al. 2004) found that Eurasian skylark breeding density, duration and success were higher in winter wheat fields with undrilled patches (4 x 4 m) than in fields with widely-spaced (25 cm apart) rows or under conventional management (0.3 nests/ha in fields with undrilled plots vs. 0.2 for the other treatments). Fields with undrilled patches also lost fewer territorial and nesting birds over the breeding season and by the end of the breeding season nests in these fields produced on average one more chick than control nests. Body condition of nestlings decreased in control nests over the breeding season but increased in experimental fields. The proportion of within-treatment foraging flights remained constant in fields with undrilled patches but decreased over time in other treatments.
A before-and-after study in Cambridgeshire, England (Donald & Morris 2005), found that the population of Eurasian skylarks on an arable farm increased from 10 territorial males in 2000 to 34 in 2005, following the use of skylark plots from 2001 (in addition to 6 m margins around fields and set-aside). Nests were also aggregated in fields with skylark plots. The study also reports that fields on 15 experimental farms with skylark plots held 30% more skylarks than control fields. In addition, nests in fields with plots produced 0.5 more chicks/breeding attempt.
A replicated, controlled study in 2002-3 on ten farms in England (Ogilvy et al. 2006) found that 45% of 159 Eurasian skylark nests monitored were found in fields with skylark plots. By June, fields with plots held 30% more skylarks and 100% more nests than control fields. At the start of the breeding season there was little difference in success between treatments, but by June fields with plots in had more nests (1 nest/ha vs. 0.4) and more chicks/nest than controls (1.75 chicks/nest vs. 0.9). Over the whole season nests in experimental fields raised 0.5 more chicks per breeding attempt (and 1.5 more late in the season) than controls.
A 2007 literature review (Stoate & Moorcroft 2007) reports that on two experimental farms in the UK Eurasian skylarks were able to raise 49% more young in fields with skylark plots, compared to fields without plots, by prolonging the length of the breeding season. 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 beetle banks’.
A replicated, controlled study near Berne, Switzerland (Fischer et al. 2009) found that skylarks Alauda arvensis with territories that included undrilled patches were significantly less likely to abandon their territory than birds without patches, and more likely to use the undrilled patches as nesting and foraging sites than expected by chance. The study was from March-July in 2006 in 21 experimental sites and 16 control sites of winter wheat fields in mixed farming lands From June to July, the percentage of control fields in skylark territories decreased from 60% to 38%, whilst 55% of fields with undrilled patches remained in territories. Nest productivity was identical between control and fields with undrilled patches (1.4 chicks/territory) and there was no difference in chick body mass or tarsus length. Undrilled patches were composed of either 4 patches/ha (each 3 ? 12 m, in seven fields) or a single strip (2.5 ? 80 m, in 14 fields) sown with a mixture of six annual weed species. This study is also discussed in ‘Plant nectar flower mixture/wildflower strips’.
A replicated site comparison study on farms in three English regions (Field et al. 2010) found that skylark plots were well used (1-3 seed-eating farmland songbirds/ha) but did not have significantly more birds in than crop fields or fallow plots. Surveys were carried out on 69 farms with Higher Level Stewardship in East Anglia, the West Midlands or the Cotswolds and 31 farms across all three regions with no environmental stewardship.
- Odderskær P., Prang A., Poulsen J., Andersen P. & Elmegaard N. (1997) Skylark (Alauda arvensis) utilisation of micro-habitats in spring barley fields. Agriculture, Ecosystems & Environment, 62, 21-29
- Morris A.J., Holland J.M., Smith B. & Jones N.E. (2004) Sustainable Arable Farming For an Improved Environment (SAFFIE): managing winter wheat sward structure for Skylarks Alauda arvensis. Ibis, 146, s155-162
- Donald P.F. & Morris T.J. (2005) Saving the sky lark: new solutions for a declining farmland bird. British Birds, 98, 570-578
- Ogilvy S.E., Clarke J.H., Wiltshire J.J.J., Harris D., Morris A. & Jones N. (2006) SAFFIE - research into practice and policy. Proceedings of the HGCA Conference, Arable crop protection in the balance: Profit and the environment, 14.1-14.12.
- 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
- Fischer J., Jenny M. & Jenni L. (2009) Suitability of patches and in-field strips for sky larks Alauda arvensis in a small-parcelled mixed farming area. Bird Study, 56, 34-42
- Field R.H., Morris A.J., Grice P.V. & Cooke A.I. (2010) Evaluating the English Higher Level Stewardship scheme for farmland birds. Aspects of Applied Biology, 100, 59-68