Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Factors determining winter densities of birds on environmentally sensitive area arable reversion grassland in southern England, with special reference to skylarks (Alauda arvensis)

Published source details

Wakeham-Dawson A. & Aebischer N.J. (1998) Factors determining winter densities of birds on environmentally sensitive area arable reversion grassland in southern England, with special reference to skylarks (Alauda arvensis). Agriculture, Ecosystems & Environment, 70, 189-201


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Create open patches or strips in permanent grassland Farmland Conservation

A randomized, replicated, controlled trial in winter 1995-1996 in southern England (Wakeham-Dawson & Aebischer 1998) found more Eurasian skylarks Alauda arvensis on seven fields with open strips than in seven control fields without strips, but the variation in numbers was so great that these differences were not significant (2-55 skylarks/km2 on treated fields vs 0 on controls). Open strips were created in a grid pattern, 25 m apart, using a tine-cultivator in November 1995. Experimental fields were still significantly more open in May 1996, but the swards had closed entirely by February 1997. The number of skylarks was recorded on three visits/month from December 1995 to February 1996 on 14 fields.

Create open patches or strips in permanent grassland Bird Conservation

A randomised, replicated and controlled trial on 14 fields in southern England in winter 1995-6 (Wakeham-Dawson & Aebischer 1998), found more Eurasian skylarks Alauda arvensis on seven fields that had open strips created in them, than in seven control fields, but the variation in numbers was so great that these differences were not significant (2-55 skylarks/km2 on treated fields vs. 0 on controls). Open strips were created in a grid pattern, 25 m apart, using a tine-cultivator in November 1995. Experimental fields were still significantly more open in May 1996, but the swards had closed entirely by February 1997. This study is also described in ‘Revert arable land to permanent grassland’ and ‘Habitat restoration and creation’.

 

Revert arable land to permanent grassland Bird Conservation

A replicated, controlled study in the winters of 1994-7 on farmland in southern England (Wakeham-Dawson & Aebischer 1998) found that Eurasian skylark Alauda arvensis, corn bunting Miliaria calandra and meadow pipit Anthus pratensis were not consistently more abundant on arable land reverted to grassland than on intensively managed permanent grassland or winter wheat fields (4-11 birds/km2 for skylarks on reverted fields vs. 0-10 and 1-8 birds/km2 for permanent grassland and winter wheat; values were 0.1-0.2, 0 and 0-1 birds/km2 for buntings and 0-1.1 0 and 0-4 birds/km2 for pipits). Densities of rooks Corvus frugilegus did not differ across field types. Reverted arable fields were sown with agricultural grass mixtures and managed under specific guidelines, whilst the permanent grassland fields were mown frequently and fertilised. This study also describes the effects of ‘Habitat restoration/creation’ and is discussed in ‘Create open patches or strips in permanent grassland’.

 

Convert or revert arable land to permanent grassland Farmland Conservation

A replicated, controlled study in the winters of 1994-1997 in southern England (Wakeham-Dawson & Aebischer 1998) (same study as Wakeham-Dawson et al. 1998) found that Eurasian skylarks Alauda arvensis, corn buntings Miliaria calandra and meadow pipits Anthus pratensis were not consistently more abundant on arable land reverted to grassland than on intensively managed permanent grassland or winter wheat fields (4-11 skylarks/km2 on reverted fields vs 0-10 and 1-8 on permanent grassland and winter wheat; 0.1-0.2 corn buntings/km2 on reverted fields vs 0 and 0-1;  0-1.1 meadow pipits/km2 on reverted fields vs 0 and 0-4). Densities of rooks Corvus frugilegus did not differ across field types. Reverted arable fields were sown with agricultural grass mixtures and managed under specific guidelines, whilst the permanent grassland fields were mown frequently and fertilized. Fields on forty farms were surveyed. Birds were surveyed once during December and January on 217 fields in winter 1994-1995, repeated on 205 fields in winter 1995-1996 and on 225 fields in winter 1996-1997.

 

Restore or create grasslands Bird Conservation

A replicated, controlled study in the winters of 1994-1997 on farmland in southern England (Wakeham-Dawson & Aebischer 1998) found that Eurasian skylarks Alauda arvensis, corn buntings Miliaria calandra and meadow pipits Anthus pratensis were consistently more abundant on arable fields reverted to species-rich chalk grassland (36-37 fields surveyed annually) than on land reverted to permanent grassland (71-80 fields sown with agricultural grasses), intensively managed permanent grassland (12-17 fields) or winter wheat (23-33 fields) fields (25-230 birds/km2 for skylarks on reverted chalk grassland vs. 0-11 birds/km2 for other field types; 0.9-4.7 birds/km2 vs. 0-1 birds/km2 for buntings and 4-6 birds/km2 vs. 0-4 birds/km2 for pipits). Densities of rooks Corvus frugilegus did not differ across field types. Reverted chalk grassland fields were sown with species such as Festuca spp. and Bromus spp. grasses.

 

Restore/create species-rich, semi-natural grassland Farmland Conservation

A replicated, controlled study in the winters of 1994-1997 in southern England (Wakeham-Dawson & Aebischer 1998) (same study as (Wakeham-Dawson et al. 1998)) found that Eurasian skylark Alauda arvensis, corn bunting Miliaria calandra and meadow pipit Anthus pratensis were consistently more abundant on arable fields reverted to species-rich chalk grassland than on land reverted to permanent grassland (sown with agricultural grasses), intensively managed permanent grassland or winter wheat fields (25-230 skylarks/km2 on reverted chalk grassland vs 0-11 on other field types, 0.9-4.7 corn buntings/km2 on reverted chalk grassland vs 0-1 on other field types, 3.7-6.1 meadow pipits/km2 on reverted chalk grassland vs 0-4.3 on other field types). Densities of rooks Corvus frugilegus and species richness of plant seeds did not differ across field types. However, there were significantly more plant species on reverted chalk grassland than the other field types (7.8-9.2 species/quadrat vs 1.4-5.1 species/quadrat). Reverted chalk grassland fields were sown with species such as Festuca spp. and Bromus spp. grasses.  Fields on forty farms were surveyed. Birds were surveyed once during December and January on 217 fields in winter 1994-1995, repeated on 205 fields in winter 1995-1996 and on 225 fields in winter 1996-1997. The numbers of grassland birds and types of grazing livestock were recorded. In November in the winters of 1995-1996 and 1996-1997, seeds lying on the ground in 31 fields, were sampled in two 0.25 m2 quadrats/field and identified to species. Plant species were surveyed in four 0.25 m2 quadrats/field in July-August 1994 and 1996 in 121 and 72 fields.