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Silver-washed Fritillary (Argynnis paphia)
© Eddie John
The Silver-washed Fritillary is a woodland butterfly whose larvae feed on violets (Viola spp.). It tolerates a greater degree of shade than other violet feeding fritillaries and its decline has generally been less severe (For further details on this species see http://www.butterfly-conservation.org/).
Family: Nymphalidae
Status: Rapid increase
Status details:
Status since 1976 is Rapid increase with an increase of 67.8%
Status over the last 20 years is Stable with an increase of 63.4%
Status over the last 10 years is Rapid increase with an increase of 157%
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:
This species was showing a steady increase up until 1996. In 1998 it experienced the biggest drop in numbers since the 1977 crash that followed the drought of 1976. There was no drought in 1997 and the reasons for this second big drop are not known. Since 1998 numbers have increased again and in 2004 the butterfly produced its highest index since 1976.
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-washed Fritillary has been recorded from 405 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 420 sites, with an average index of 19 individuals per site.
For 201 of these sites, Silver-washed Fritillary has been recorded well enough to calculate annual indices of abundance in 6 or more years, allowing trends to be calculated.
In 2006, 11768 individuals were recorded from 220 sites, producing annual indices at 180 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
• Extinct sites (5)
• Colonised sites (4)
- Stable sites (67)
- Declining sites (13)
- Increasing sites (35)
