Shock as count sees butterfly numbers fall

BUTTERFLY numbers collapsed in Wales over the summer – with experts suggesting species were affected by a cold spring and pesticides.

The majority of species studied in the annual Big Butterfly Count saw populations fall. Some saw their worst numbers since the citizen science project began in 2010.

The results were even lower than the cold washout summer of 2012 which proved a disaster for butterflies, despite 2016 being warmer than average and relatively dry, wildlife charity Butterfly Conservation said.

Experts at the charity said the mild winter and cold spring, or even pesticides, could be among the reasons for the decline in common butterflies in Wales and across the UK.

Widespread species, including the ringlet, meadow brown and the small tortoiseshell all struggled in Wales, with numbers falling in comparison to last year.

And the numbers of the colourful peacock have seen a six-fold decrease over three years, dropping from a UK average of 3.6 individuals per count in 2013 to just 0.5 per count this year.

Butterfly Conservation’s head of recording Richard Fox said: “The drop in butterfly numbers this summer has been a shock and is a bit of a mystery.

“When we have cold, wet summers, as in 2012, we expect butterfly populations to plummet, but that wasn’t the case this year.

“The summer months were warmer than usual, yet most Big Butterfly Count participants saw fewer butterflies.

“Perhaps the very mild winter had a negative effect, or the cold spring, or perhaps the impacts of intensive farming and pesticides are really hitting these common species now.”

In Wales common white butterflies all bucked the general trend of decline to record good summers, including the large white, which saw an increase of 85% in its population.

More than 36,000 people took part in this year’s Big Butterfly Count.