Dark Green Fritillary (Argynnis aglaja)
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© Nick Greatorex-Davies
The widespread Dark Green Fritillary is a species of Bracken hillsides and open flower-rich grasslands such as chalk downs, coastal grassland, dunes and sometimes woodland rides and glades. Eggs are laid on Marsh Violet (Viola palustris) or Hairy Violet (V. hirta), depending on the habitat, generally in taller herbaceous vegetation than some of its relatives. The butterfly its declining in parts of its range. (For further details on this species see http://www.butterfly-conservation.org/).
Status details :
Status since 1976 is Rapid increase with a increase of 160%
Status over the last 20 years is Rapid increase with a increase of 83%
Status over the last 10 years is Stable with a decrease of -11.6%
Log 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 :
The Dark-Green Fritillary is one of the few fritillaries showing an increase across UKBMS sites since 1976, and one of only two where this increase is significant. It has the most widespread range of all the fritillaries across UKBMS sites and has produced site indices on around 500 different transects, reflecting its less specialised habitat requirements compared to other fritillaries.
This map shows the distribution between 1995 and 2016. Data is derived from the Butterflies for the New Millenium dataset via the NBN Gateway
This chart shows the average number of butterflies seen on transects between Arpil and October across all sites (fitted values from a Generalised Additive Model). The blue line gives average counts over the full BMS series (1976 to date) and the red line gives the average for the last year.
This map shows symbols for the mean abundance at transect sites, with the colour of the symbol reflecting the level of abundance. Means are over all years. Grey background squares are the occupied cells as shown by the Butterflies for the New Millenium over the previous ten year period.
In total, Dark Green Fritillary has been recorded from 410 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 448 sites, with an average index of 14 individuals per site.
For 224 of these sites, Dark Green Fritillary has been recorded well enough to calculate annual indices of abundance in more years, allowing trends to be calculated.
In 2018, 8072 individuals were recorded from 166 sites, producing annual indices at 140 of these.
Links to counts
This map shows the trend in abundance at particular transect sites for which data has been received within the last five years. Trends (increasing, declining or stable) are assessed at sites where the species has more than five years of annual index data. Use the option boxes below to view plots for individual sites.
Links to lists of sites with particular statuses
|Colonised sites (17)|
|Extinct sites (15)|
|Stable sites (157)|
|Increasing sites (51)|
|Declining sites (28)|