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Silver-spotted Skipper (Hesperia comma)
© Nick Greatorex-Davies
The Silver-spotted Skipper is a rare butterfly in Britain occurring in discrete colonies on open sunny short chalk grassland, usually breeding where its larval foodplant Sheep's Fescue (Festuca ovina) grows next to patches of bare ground. In recent years it has colonised many unoccupied sites and has been observed egg-laying in short grassland in the absence of bare ground, probably a response to a warmer climate and therefore microclimate in the swards where it breeds. (For further details on this species see http://www.butterfly-conservation.org/).
Family: Hesperiidae
Status: Rapid increase
Status details:
Status since 1976 is Rapid increase with an increase of 2301.4%
Status over the last 20 years is Rapid increase with an increase of 522.5%
Status over the last 10 years is Stable with a decrease of -3.2%
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:
When the scheme began in 1976 the Silver-spotted Skipper was recorded on just two BMS transects. This number has increased gradually over the years and for the past 10 years Annual Indices have been produced for between 7-9 sites each year. Despite this low number of sites the trend shows a highly significant increase over the monitoring period indicating that the butterfly has been increasing in abundance as well as range. This increase in range and abundance is thought to be partly due to climate change which has resulted in a warmer microclimate at ground level making more of its hostplant available in a suitable condition for oviposition and larval development. In addition rabbit grazing has increased which again has made more areas suitable for this species.
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, Silver-spotted Skipper has been recorded from 194 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 90 sites, with an average index of 32 individuals per site.
For 41 of these sites, Silver-spotted Skipper has been recorded well enough to calculate annual indices of abundance in 6 or more years, allowing trends to be calculated.
In 2006, 2495 individuals were recorded from 38 sites, producing annual indices at 32 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
• Colonised sites (5)
- Stable sites (14)
- Declining sites (2)
- Increasing sites (15)
