Small Skipper Thymelicus sylvestris
Family: Hesperidae, (The Skippers)
Still common and widespread but while extending its range in the North and West is declining in many localities . From its zenith in the mid 90's when it was the most common grassland species it is now Yorkshire's most rapidly declining widespread species. Where once there were 3 figure counts on good sites now it is in the tens.
Female by Catherine Jones
The Small Skipper is one of our three golden skippers species in Yorkshire. When at rest the forewings are often held upwards in a V-shape, and hindwings horizontal and with its unusually large body gives it a very moth like appearance. This is characteristic 'skipper' fashion earning its nick name of 'bull head'. With a wingspan is 27-34mm freshly emerged specimens are golden brown with a narrow black margin that becomes drab when worn. The undersides are much paler. Male and females are alike except that males have a sex brand, which is a thin, black, slightly curving line on upper forewings. Their flight is fast and darting and the butterflies can be hard to see when nectaring or resting on flowers because of their brown-ish colour. They respond well to sunshine and fly about but drop down into vegetation or become very still if the sky clouds over or it rains.
All the skippers are capable of flying at such a speed in warm weather they are a blur. Their flight is often very straight and directional and along with their small size gives us our first clues. If it is predominatly a greyish or dark blur then its likely a Dingy rather than one of the golden skippers. The Skippers actually derive their name from when flying slowly amongst long grasses with their characteristic skipping or' jinking of short wings beats maneovouring between stems. While at rest it takes a mothlike posture is the next clue.
The largest source of confusion of Small Skipper is with Large Skipper but is very easily distinguished at rest by the presence of light spots on the upper and lower wings. Indeed any spots makes it a Large skipper. Habitat will also give us a clue when Large skippers very much favour damper areas with lusher grasses plus also emerge nearly a month earlier so are decling by the time Small skipper emerge You only need to attempt the differentiate Essex skipper if your site is know to have them .
Speed, size, spots, habitat, date
There is a consistent long term decline of Small Skipper which continues a pace having lost 50% in abundance since 2003 which is worrying for what used to be our most common grassland butterfly. Year to year it shows a great variation in abundance by a factor of 5+ but generaly follows the weather patterns booming in 2006 then again in 2014, both good summers but this was not repeated in 2018-19. There are signs the trend is stablising at a lower level but there has been no repeat of the booms in the present run of good summers.
There may well be a combination of factors of not only higher temperatures but also nitrogen deposition altering habitat and suitability of grassland, We are already beginning to loose this species from some of our managed sites
Abundance Trend (Average transect indices) -59% with a correlation 0.25 (weak)
Occupancy Trend ( % of visited tetrads)
-27% with a correlation of 0.71(strong)
With thanks to The Butterflies of Yorkshire edited by Howard M Frost
Catherine Jones 04/01/21