Peacock (Aglais io)
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© Eddie John
The familiar Peacock butterfly is a relatively mobile and wide-ranging butterfly of parks, gardens and woodland edges where its larvae feed gregariously on Stinging Nettle (Urtica dioica) in sheltered situations. The species is expanding its range northwards in northern England and Scotland. (For further details on this species see http://www.butterfly-conservation.org/).
Status details :
Status since 1976 is Stable with a increase of 11%
Status over the last 20 years is Stable with a decrease of -31.4%
Status over the last 10 years is Stable with a decrease of -3.6%
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 :
Though the Peacock has generally increased since 1976, the increase is not significant across the UK and more recently populations have started to decline. However, it has colonised a number of sites in Scotland since monitoring began, reflecting its northward range expansion described in the atlases produced by data from the Butterflies for the New Millennium project, and now is a common butterfly there. Indeed in Scotland the long-term trend for this species is a significant increase and the recent declines seen in England and Wales have not yet been mirrored. This may be the result of climate change and consequent increased overwintering success.
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, Peacock has been recorded from 905 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 1006 sites, with an average index of 38 individuals per site.
For 438 of these sites, Peacock has been recorded well enough to calculate annual indices of abundance in more years, allowing trends to be calculated.
In 2017, 19516 individuals were recorded from 626 sites, producing annual indices at 416 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 (11)|
|Extinct sites (1)|
|Stable sites (596)|
|NA sites (1)|
|Increasing sites (111)|
|Declining sites (72)|