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Clouded Yellow (Colias croceus)
© Eddie John
The Clouded Yellow is a highly mobile species that occurs in Britain as a migrant from southern Europe in highly variable numbers annually. It breeds on vetches and clovers in open sunny situations. It has been recorded surviving our British winters on the south coast in recent years. (For further details on this species see http://www.butterfly-conservation.org/).
Family: Pieridae
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 migrant species is not recorded on BMS transects every year and numbers recorded vary considerably from year to year. The data show no significant trend. However, relatively high counts have been recorded every other year since 1992 and also in each of the last three years suggesting that immigrants to the Britain are becoming more frequent, perhaps in response to warmer temperatures as a result of climate change.
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, Clouded Yellow has been recorded from 539 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 667 sites, with an average index of 2 individuals per site.
For 350 of these sites, Clouded Yellow has been recorded well enough to calculate annual indices of abundance in 6 or more years, allowing trends to be calculated.
In 2006, 2787 individuals were recorded from 296 sites, producing annual indices at 232 of these.
