Butterfly Conservation- Glasgow & South West Scotland Branch
Small Heath (Coenonympha pamphilus) - PRIORITY SPECIES
The Small Heath is a wee orange-brown butterfly (wingspan 33-37 mm) that flies only when the sun is shining. Both sexes are similar in appearance, although the female is slightly larger. The pale orange upper wings are almost never shown, as the wings are held shut at rest. The underside of the forewing is a variable shade of orange fading to grey at the edges, with a small eyespot that is visible shortly after landing, before getting hidden behind the duller grey-brown hindwing. The butterfly has a characteristic lazy bobbing flight, generally moving only a few metres, staying close to the ground, before landing and angling wings towards the sun to bask. The adults have a preference for yellow flowers such as dandelions, ragwort or hawkbits. The Small Heath is often seen as a solitary individual or in small colonies, but larger colonies can be found on upland grassland and grassy slopes.
The Small Heath tends to be single brooded in South West Scotland. The adults begin to emerge from mid May and set about forming territories and finding mates. A colony breeding strategy known as lekking has been observed in this species whereby the males in a colony congregate near a distinctive landmark such as a prominent bush, and compete with each other in spiral flight-battles to assert dominance. Females visit these leks to find a mate then disperse to lay their eggs. The pale green eggs are laid singly on fine-leaved grasses such as fescues (Festuca Spp.), meadow-grasses (Poa Spp.) or bents (Agrostis Spp.). The green caterpillar has a dark green stripe along itís back and develops slowly throughout the summer and autumn before hibernating at the base of the grass tussock. Feeding resumes during warm days in spring, before forming a green pupa among the grass stems.
In South West Scotland the Small Heath can be found on the wing from mid May to early September, with a peak between late May and early August.
Habitat & Distribution in SW Scotland
Distribution map 2010
The Small Heath is quite widespread within the branch area and can be found in drier grassy habitats in most places provided the grass is not cut or heavily grazed.
The Small Heath can be found in a variety of grassland habitats from mountain slopes down to coastal grasslands or wet blanket bogs and may even be seen in small numbers in city parks - one seen at the unmown Hill 60 at Queens Park, Glasgow in 2007. At blanket bog sites it may be seen flying with itís larger cousin, the Large Heath (Coenonympha tullia). Confusion can occur in areas where the Scotica subspecies of Large Heath is found, as this form looks very similar to a large-sized Small Heath. The Small Heath is still relatively common and widespread in South West Scotland, however the species has suffered a decline across much of Britain. The reasons for this decline remain a mystery but it is clear that strong colonies can quickly be destroyed by changes in land management such as grassland Ďimprovementí, afforestation, overgrazing or ploughing for arable crops.
- Futter, K., Sutcliffe, R., Welham, D., Welham, A., Rostron, A., MacKay, J., Gregory, N., McCleary, J., Tait, T., Black, J. & Kirkland, P. 2006. Butterflies of South West Scotland. Argyll Publishing. (see Atlas page)
- Asher, J., Warren, M, Fox, R., Harding, P., Jeffcoate, G., Jeffcoate, S. 2001. The Millennium Atlas of Butterflies in Britain & Ireland. Oxford University Press.
- Tomlinson, D. & Still, R. 2002. Britainís Butterflies. WILDGuides.
Written by Scott Shanks