Butterfly Conservation- Glasgow & South West Scotland Branch
Small Skipper (Thymelicus sylvestris)
The Small Skipper is one of two golden-orange skippers to arrive in South West Scotland in recent years. Despite its name, the Small Skipper isnít the smallest skipper in the UK! It is an active little butterfly with a rapid buzzing flight and golden-orange wings (Wingspan 27-34 mm) that are held in the distinctive skipper posture when at rest. The sexes are similar, but the male has a dark band of pheromone scales on their forewing known as the sex brand. The Small Skipper is virtually identical to the closely related Essex Skipper (Thymelicus lineola), but the tips of its antenna are dark brown or orange, while those of the Essex Skipper are black. The Small Skipper and the Essex Skipper have only recently expanded their range into South West Scotland, arriving 2006 and 2008 respectively. Both species seem to be responding positively to changes in climate and land use by spreading northwards.
After emerging in June, the males set about forming territories near long uncut grasses and finding mates. Much of the rest of the time is spent nectaring and basking in the sun. Females tend to be quite sedentary and make slow deliberate egg-laying flights. One brood is produced each year. The female lays clusters of eggs in the leaf sheathes of Yorkshire-fog (Holcus lanatus). Occasionally other grasses such as Timothy (Phleum pratense), Creeping soft-grass (Holcus mollis), Cockís foot (Dactylis glomerata) or False brome (Brachypodium sylvaticaum) may also be used. The eggs are initially white, but darken to a pale yellow and take 20-25 days to hatch. Immediately after hatching the green caterpillar (which has a dark green stripe down itís back) feeds on its own eggshell and then goes into hibernation in a silk cocoon within the leaf sheath. The following spring the larva becomes active on warm days, feeding initially within a rolled tube of grass held together by silk. The green pupa is formed in a tent of leaves at the base of the grass tussock.
There havenít been enough records yet in South West Scotland to accurately determine flight periods in our branch area, but the few sightings have been in late July and early August. In England adults can be found on the wing from mid-June through to mid-September, with a peak in numbers in July.
Habitat & Distribution in SW Scotland
Distribution map 2010
Small Skipper colonies may potentially be found wherever grasses are allowed to grow tall. In England it is a widespread and relatively common species associated with rough grasslands, downs, roadside verges, field margins, sunny rides and woodland clearings. Some colonies can be quite large, but even small areas of suitable habitat may support a small colony. Small Skippers will nectar from a wide range of plant species including knapweed, thistles, clovers and birds-foot trefoil, but individuals tend to look for flowers of the same species or similar flower structure from what theyíve fed on before.
The Small Skipper is currently undergoing a dramatic range expansion in Britain and is not considered a species of conservation concern.
The rate of range expansion is quite remarkable given that recent studies have shown that most individuals move less than 20 m per day.
While the spread of the Essex Skipper is considered most likely to be an accidental introduction into Scotland, the spread of the Small Skipper is almost certainly natural colonisation as the National Butterfly Atlas for 2000-2004 showed it to be spreading rapidly north and close to the Scottish Border. The first records occurred in 2006 near Lockerbie but at present, the Small Skipper in the SW branch area is only known from three 1 km squares whereas Essex Skipper is known from five 1 km squares. However, in the East of Scotland branch area, there are a 14 records of Small Skipper from nine 1 km squares between 2006 and 2010.
- 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.
- Fox, R., Asher, J. Brereton, T., Roy, D. and Warren, M. 2006. The state of Butterflies in Britain and Ireland. Pisces Publications.
- Sutcliffe, R. 2009. Recent changes in the distribution of some Scottish butterflies and the arrival of
new species in Scotland. The Glasgow Naturalist Volume 25, Part 2, 5-12
Written by Scott Shanks and Andrew Masterman