The warm start to 2014 boosted the numbers of some butterflies including the critically endangered High Brown Fritillary. More than half of the 56 species studied in the UK Butterfly Monitoring Scheme saw their numbers rise compared with the previous year.
The High Brown Fritillary was once widespread across England and Wales but numbers have declined rapidly since the 1970s. It is now down to a single colony in Wales and only two remaining strongholds in England but has benefitted from schemes to restore habitat; 2014 was its best year for a decade. The warm, wet spring of 2014 was good for emerging caterpillars and wildlife-friendly farming schemes to restore the woodland and moorland slopes where it breeds have helped bolster its populations.
2014 was also a good year for other species of butterfly which emerge early in the year including the Marbled White, Ringlet, and Brimstone which all had their best year since the survey began in 1976. The rare Lulworth skipper increased by 26% and the threatened Duke of Burgundy also fared well last year.
Some butterflies that emerge in high summer struggled with the colder weather of August 2014. This included the Chalkhill Blue, Adonis Blue, and the two “cabbage white” species. Overall 32 of the 56 species recorded by the monitoring scheme saw their number rise compared to 2013, one saw no change, and 23 species saw numbers fall.
Sources: BBC website (April 2015), Guardian online (April 2015)