SCOTLAND’S butterflies are in drastic decline with a 70% drop in numbers - the worst crash in a decade.

The annual Big Butterfly Count was published yesterday, and Scotland’s drop was twice that of the rest of the UK, where the drop was 34%.

Of the 17 species logged in the Scottish survey, 10 were found to have declined compared to last year.

The weather, habitat loss and climate change are believed to contribute to the long term drop in numbers,

Butterfly Conservation said the downward trend was seen across many varieties of the insect, with the Painted Lady, Scotland’s most common species in 2019, falling to 13th place after numbers halved.

Other species including the Peacock, down 56%, and Red Admiral, down 50%, also suffered dramatic reductions.

The most commonly seen butterfly this year was the Small Tortoiseshell, with nearly 5000 recorded. Despite that, numbers seen were 21% fewer on average compared with 2019.

The second most spotted species, the Small White, fell by 25%, ahead of the Large White, down 5%.

Dr Zoë Randle, senior surveys officer at Butterfly Conservation said the drop could be down to a warm spring.

She said: “Unfortunately, this summer has not seen an abundance of butterflies, across the UK.

“The fall in butterfly numbers this summer may be due to a number of factors. An unusually warm spring led many species to emerge earlier than usual, so we may have only caught the tail-end of the flight period for many species during this year’s Big Butterfly Count.”

She said their scientists would analyse the data to try and ‘understand what is happening and how we can work to solve it.’

“70% is the biggest percentage decline since the Big Butterfly Count began and the second lowest average number of individual butterflies seen per count,” she added.

The Big Butterfly Count is an annual event designed to help assess the health of the environment by counting butterflies and some day-flying moths around the UK.

Members of the public spend 15 minutes in an outdoor space counting the number and type of butterflies they see, with increases or declines calculated on the average number per count.

A total of 3207 people in Scotland produced 4188 counts between July 17 and August 9.

However, of the 17 butterfly species included in the study, only seven were seen in greater numbers than last year during counts.

The biggest winner was the Six-spot Burnet, a day-flying moth, which climbed to ninth place north of the Border after jumping by 208% from last year, while the Meadow Brown became the fourth most common species after enjoying a 100% increase.

Other Scottish winners this year include the Ringlet (up 94%); Common Blue (up 71%); Speckled Wood (up 31%) and Small Copper (up 27%), while the Green-Veined White also increased, by 5%.

However, only 6.46 butterflies were seen per count in Scotland - the second lowest only to 2017 when there was an average of 6.12.

Last year, participants recorded 21.8 butterflies on average per count.

In all, during this year’s count, over 1.4 million butterflies were counted across the UK.

Despite the drop in numbers, 2020 saw the highest number of butterfly sightings submitted, with 111,628 participants submitting a record-breaking 145,249 counts this year - an increase of 25% on 2019.

Dr Randle said: “Butterflies are highly susceptible to fluctuations in annual weather, but the bigger picture is that on the whole species are declining. Overall, since the 1970s, we’ve seen three quarters of our butterfly species suffer from decline.

“The main drivers are habitat loss through urbanisation, agricultural intensification and land management changes, and climate change.

“In some instances, we’ve seen species that want to expand their range north because of climate change but if the habitat isn’t there for them they are prevented from doing so - it’s a checkmate situation.”