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Brown Hairstreak (Thecla betulae)
© Eddie John
The Brown Hairstreak is an elusive species of hedges, scrub and woodland edges where it requires a good supply of young Blackthorn (Prunus spinosa) growth for breeding. It has declined substantially in Britain due to extensive hedgerow removal and the annual flailing of many remaining hedges. (For further details on this species see http://www.butterfly-conservation.org/).
Family: Lycaenidae
Status: Insufficient information
Status details:Insufficient information
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 rare canopy dwelling species is not suited to transect monitoring, however it is recorded, generally in very low numbers, on about 10 BMS transects, three of them almost annually. Although not significant, there is a suggestion in the data that numbers may be increasing.
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, Brown Hairstreak has been recorded from 128 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 75 sites, with an average index of 1 individuals per site.
For 25 of these sites, Brown Hairstreak has been recorded well enough to calculate annual indices of abundance in 6 or more years, allowing trends to be calculated.
In 2006, 35 individuals were recorded from 13 sites, producing annual indices at 11 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 (3)
- Stable sites (10)
- Declining sites (1)
- Increasing sites (2)
