Habitats

Butterfly habitat types within the Gloucestershire area

Each of our resident butterfly species needs to be able to lay its eggs on or close to the appropriate foodplant(s). Some use only one species of plant (which may be a wild flower, type of grass, shrub or tree) but others may use any of several foodplants.

Because of their foodplant requirements, some species have colonies which are restricted to particular types of place where those plants occur. Such species are the ones which are most in need of protection from habitat loss, whether by destruction, unsympathetic management or neglect.

Several common butterfly species may be seen in gardens and parks - or anywhere in the countryside.

The best sites for uncommon butterfly species in the area are mostly:

Unimproved grasslands - flower-rich grasslands which have not been treated with fertilisers

Open woodlands - usually large areas of commercial forestry kept partially open by harvesting such as in the Forest of Dean

Old industrial sites - particularly disused quarries and railway lines

Other good sites include:

Hedgerows, unsurfaced tracks and road verges - these often provide linear remnants of flower-rich grassland or woodland habitat surrounded by crops or improved grassland

Heathland - a scarce habitat being restored in places in the Forest of Dean area

Unimproved grasslands

Unimproved grassland habitat occurs throughout the county, but most is found on the oolitic limestone of the Cotswold Hills. Such sites are still rich in wild flowers and butterflies. There are several large areas with good public access, particularly along the western edge of the Cotswolds from Cleeve Common north-east of Cheltenham to Stinchcombe Hill at Dursley. Almost all of the grassland butterfly species in the area can be found at some or all of these places.

Other good Cotswold edge sites include

the Prestbury Hill Reserve, owned by Butterfly Conservation, just south of Cleeve Common

Crickley Hill, south of Cheltenham

Painswick Hill

Rodborough Common, south of Stroud

Prestbury Hill, Cheltenham

Stinchcombe Hill, Dursley

A secluded Cotswold valley

Within the Cotswolds hills are many other areas of unimproved grassland, some large but most quite small. Some are commons, there is public access on footpaths through some good private sites, and some of the sites are Gloucestershire Wildlife Trust nature reserves.

Edge Common, near Painswick

Grassland slope at a GWT reserve

A slope too steep for farm machinery

Unimproved grassland elsewhere in the county does not support quite so many butterfly species as the Cotswold grasslands, because of the range of larval foodplant species found on these sites. Typical plants include Kidney Vetch (Anthyllis vulneraria) used by the Small Blue, Horseshoe Vetch (Hippocrepis comosa) used by the Chalk-hill Blue, and Rock-rose (Helianthemum nummularium) used by the Brown Argus.

The adult butterflies need plenty of nectar from wild flowers. The best sites are those with enough grazing to prevent grasses from growing so tall and dense that they crowd out the flowers, but not too much grazing in the summer (or too many flowerheads are lost). Density of grazing is a Conservation issue.

Scrub (tree saplings, and various shrubs including gorse and hawthorn) grows on many grasslands. Whilst it provides some benefits for butterflies (shelter, and nectar or larval foodplants for some species) it can also spread over the whole area and destroy the grassland habitat (another Conservation issue).

Open Woodlands

Most woodland butterflies need habitat which includes open areas, letting in plenty of sunlight: wide tracks, clearings, and areas felled in recent years not yet shaded too much following replanting or regeneration of trees.

To some extent, such open areas may be like grassland or scrub habitat, and some of the grassland butterflies may also be found in open woodland.

The Forest of Dean includes extensive areas of plantation, but also many wide forestry tracks including old railway lines. Felling operations result in new open areas, ensuring a continuing supply of young plantation habitat. A good range of butterfly species may be found in the Forest.

Some Cotswold woodlands are also managed as commercial forestry with frequent felling. Many however are allowed to grow to maturity without enough management to prevent the loss of butterfly habitat. When eventually there is some felling, it may be too late for some species lost from the area - their nearest colony may be so far away that natural recolonisation is very unlikely (a Conservation issue).

Forest of Dean

Forest of Dean

A Cotswold wood

Lower Woods, Severn Vale

Old industrial sites

There are many disused quarries in the Cotswolds, including small ones previously used very locally for the dry-stone field walls. Most have been disused for a long time, and have reverted to grassland with shallow soil, or to scrub and woodland. Their unsuitability for agriculture has often protected the habitat.

There are also quarries in the west of the county, on the carboniferous limestone.

The old network of railway lines was created at a time when the surrounding countryside was rich in grassland butterfly habitat. Tracksides, embankments and cuttings along disused railways still provide some very good habitat through areas where crops are now grown.

A common feature of such sites is very shallow soil and short, sparse vegetation grazed by rabbits and deer perhaps, but usually not by sheep or cattle. They can also be quite sheltered, so they provide a hotter microclimate than more open areas with more vegetation.

Some of the lakeside habitat in the Cotswold Water Park (created by gravel extraction) is good for some butterfly species.

Old quarry on Painswick Hill

Old railway cutting in the Cotswolds

Forest of Dean	Forest of Dean
A Cotswold wood	Lower Woods, Severn Vale