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Lulworth Skipper (Thymelicus acteon)
© Eddie John
The Lulworth Skipper has a very restricted distribution in Britain. Where it occurs it can be locally very abundant in tall unmanaged calcareous grassland where its foodplant Tor Grass (Brachypodiun pinnatum) grows in abundance. (For further details on this species see http://www.butterfly-conservation.org/).
Family: Hesperiidae
Status: Stable
Status details:
Status since 1976 is Stable with a decrease of -58.7%
Status over the last 20 years is Stable with a decrease of -44%
Status over the last 10 years is Stable with a decrease of -22.9%
Back to the topLog collated index plot
This chart shows the index of abundance (LCI = Log Collated Index) over time. It shows fluctuations in populations from year to year, and is scaled so that the average index over the whole series is equal to 2 (horizontal line). For greater detail about how this index is derived, click on the green question mark above.
Trend description:
There have been big fluctuations in the Annual Indices for this species at the single BMS transect (Ballard Down, Swanage) where this species is recorded. High indices in earlier years were probably when the site supported more areas of tall grassland where Tor Grass was dominant. The site has since been managed (more heavily grazed) to produce a shorter sward, primarily for the Adonis Blue.
Distribution...
This map shows the distribution between 1995 and 1999. Data is derived from the Butterflies for the New Millenium dataset via the NBN Gateway (www.searchnbn.net).
View the distribution on the NBN GatewayPhenology...
Phenology plot
Phenology plot
This chart shows the average number of butterflies seen on transects between Arpil and October. The black line gives average counts over the full BMS series (1976 to date) and the red line gives the average for the last year.
Abundance...
Abundance
This map shows symbols for the mean abundance at transect sites, with the size of symbol reflecting the level of abundance. Means are over all years.
Coverage
In total, Lulworth Skipper has been recorded from 90 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 14 sites, with an average index of 110 individuals per site.
For 6 of these sites, Lulworth Skipper has been recorded well enough to calculate annual indices of abundance in 6 or more years, allowing trends to be calculated.
In 2006, 640 individuals were recorded from 8 sites, producing annual indices at 7 of these.
This map shows the trend in abundance at particular transect sites. Trends (increasing, declining or stable) are assessed at sites where the species has more than five years of annual index data. Click on the green question mark next to the species name above for more details on how trends are calculated.
Links to lists of sites with particular statuses
- Stable sites (4)
