The skylark is a small brown songbird with white underparts. It has a short crest on its head and white outer tail feathers.
Although its plumage may not be the most spectacular among British birds, the skylark has a special place in many people's affections for its display song. A rapid flow of notes can be delivered without a break for up to five hours. When displaying, birds often fly at such a height that they are visible, if at all, only as specks in the sky. The males sing continuously in the spring while flying over their nesting habitat. Their energetic song has inspired composers like Vaughan-Williams and poets such as Shelley and Wordsworth (1).
British skylarks are sedentary, but their numbers are augmented in winter by an influx of 2.5 million birds from northern Europe (2).
Main Habitat(s): Nest in treeless, short grassland habitats. Found in saltmarsh, heathland and arable farmland.
At the time of the first Breeding Bird Atlas (3), the skylark was the most widely distributed breeding bird in Britain. Although its distribution has not contracted a great deal, BTO data demonstrates a decline on lowland farmland of 54% between 1969 and 1991 (4). This represents a loss of 1.6 million pairs in just 23 years (numerically, a greater loss than for any other species in this time frame).
The skylark is on the 'Red List' of 'Birds of Conservation Concern' (5). A UK Species Action Plan has been produced (6). It is also protected under the Wildlife & Countryside Act 1981.
It is still a widespread breeding bird in North West England. No data are available but it is thought that the decline on lowland farmland has mirrored the national decline.
The skylark is a regional biodiversity indicator highlighting the status of lowland farmland birds.
The main concentrations and highest densities of skylarks in the county appear to be in West lancashire and in the south Pennines. The mean density of breeding pairs is 2.5 per square km. It is estimated that there are 7000 pairs in Lancashire and North Merseyside.
Populations in upland Lancashire are important. However, they appear to be declining in a similar fashion to those of lowland farmland.
Map(s): Density of breeding pairs of Skylark (Alauda arvensis) in Lancashire according to data collected by Lancashire Bird Club.
Current factors affecting the species
The switch from spring-sown to autumn-sown cereals is the most important factor in the decline of skylarks in arable areas.
Skylarks only nest in vegetation less than 25 cm tall. Spring-sown cereals allow breeding pairs to raise up to three broods per year. Autumn-sown crops usually allow only a first brood before the crop is too high. One brood per year is insufficient to maintain populations. This effect is exacerbated by the general move away from mixed farming systems, which reduces the opportunities for breeding pairs to find alternative nesting habitat within arable areas where they can raise second or third broods.
Another important factor that makes autumn-sown cereals less attractive for skylarks is the fact that they do not have the winter stubbles that are associated with spring-sown crops. Stubblefields are the preferred winter feeding habitat for skylarks and a range of lowland farmland birds.
Intensive use of agrochemicals on arable fields tends to diminish the skylarks' food sources (weed seeds and insect prey), in turn reducing breeding success.
The reasons for decline in the uplands are less well known but, again, these have been linked with changes in farming practice.
In pastoral systems, the switch from hay to silage has increased nest mortality due to cutting during the nesting season. Early silage cutting not only destroys nests directly but also exposes ones that are left to predators. Reseeding of pastures with pure stands of rye grass reduces the diversity of insect prey. Intensive grazing of pasture and saltmarsh can create a sward that is too short for nesting skylarks.
On the urban fringes, in particular, there has been a loss of grassland habitat to development and tree-planting. The loss of breeding skylarks from at least one site in Darwen followed amenity tree-planting to 'improve the environment'.
Current Action / Mechanisms
The skylark is protected under the EC Birds Directive and the Wildlife and Countryside Act 1981. A national SAP for this species has been published. The national target is to increase the population by 100% by 2010.
The BTO and RSPB, with sponsorship from Tesco, are engaged in detailed research into the ecology of the skylark and the reasons for its decline.
Provision of beetle banks, appropriate management of set-aside and retention of winter stubbles would all assist skylarks. Incentives such as MAFF's Countryside Stewardship Scheme, however, while they encourage the improvement of field margin habitats, offer little benefit for skylarks, which actively avoid field edges in favour of open areas of land. Arable Stewardship, which has been piloted elsewhere in England, would offer greater benefits because it would allow some of the above actions to qualify for grant-aid.
The distribution and numbers of skylarks were surveyed by the Lancashire Bird Club (LBC) during 1997-1999. Skylarks are still sufficiently common and widespread to be monitored by the BTO's Breeding Bird Survey.
Lancashire’s FWAG adviser visits farms in Lancashire as part of the 'Landwise' scheme. This project, which FWAG has developed with Sainsbury's, targets the supermarket's suppliers and aims to provide conservation advice on a whole farm basis. The RSPB has produced management guidelines that suggest steps that landowners can take for skylarks and a range of lowland farmland birds.
The Guidelines for BHS selection allow for sites to be designated if they hold a "significant proportion" of the county's population of skylarks (13).
Objectives, targets and proposed actions for skylark in Lancashire
References & additional reading:
1. Beer, S. (Ed.) (1995) An Exaltation of Skylarks. SMH Books, Pulborough, West Sussex.
2. UK Biodiversity Steering Group (1995) Biodiversity: The UK Steering Group Report. Volume 2: Action Plans. Skylark SAP p97. HMSO.
3. Sharrock, J. T. R. (1976) The Atlas of Breeding Birds in Britain and Ireland. T. & A. D. Poyser, Berkhamsted.
4. Reference needed for BTO report
5. RSPB (1996) Birds of conservation concern in the United Kingdom, Channel Islands and Isle of Man. RSPB, Sandy.
6. Reference needed for UK BAP for Skylark
7. Green, R. E. (1978) Factors affecting the diet of farmland skylarks. Journal of Animal Ecology 47: 913-928
8. Poulsen, J. G. & Sotherton, N. W. (1993) Skylarks on farmland : A species in decline. In: Game Conservancy Review of 1992.
9. Poulsen, J. G., Aebischer, N. J. & Sotherton, N. W. (1995) Comparative Ecology of skylarks Alauda arvensis on arable farmland: II. Feeding ecology of chicks in Southern England.
10. Wilson, J. D. & Browne, S. J. (1993) Habitat selection and breeding success of skylarks on organic and conventional farmland. BTO Research Report 129.
11. Wilson, J. D., Evans, J., Browne, S. J. & King, J. R. (1997) Territory distribution and breeding success of skylarks (Alauda arvensis) on organic and intensive farmland in southern England. Journal of Applied Ecology 34: 1462-1478.
12. Donald, P. F. and Vickery, J. A. (1999) The Importance of Cereal Fields to Breeding and Wintering Skylarks (Alauda arvensis) in the UK. Proceedings of a British Ornithologist's Union conference 1999.
13. Morries, G., Jepson, P. & Bruce, N. (1998) Biological Heritage Sites. Guidelines for Site Selection. Lancashire County Council, Preston.
Date: April 2001.