ONE of the UK’s most widespread butterflies is in a state of significant decline.

The Small Copper, which can be spotted in Dorset, has suffered its worst year on record, according to a study.

The annual UK Butterfly Monitoring Scheme (UKBMS) found the number of Small Coppers fell by almost 25 per cent last year compared to 2014.

It is thought this is as a result of last year’s summer being cooler than average.

Previous research carried out suggests the butterfly has experienced substantial declines over the past century due to habitat loss. It’s now thought poor weather in recent years may have aggravated this further.

The UKBMS said 34 of the 57 butterfly species monitored experienced declines and that the lack of summer warmth was a factor.

The Heath Fritillary, one of the UK’s scarcest species, also suffered its worst year on record with numbers down 16 per cent compared to 2014.

Meanwhile, the Swallowtail suffered the largest decline of any species with numbers down 65 per cent compared to 2014.

Nevertheless, a number of species did thrive in 2015. The Marbled White and Brimstone experienced their best years on record, whilst the Painted Lady saw its numbers rise by 200 per cent.

Dr Tom Brereton, head of monitoring at the Butterfly Conservation, said: “In recent years it has become apparent that some of our most familiar and cherished butterflies are declining substantially. Sadly, our latest results show that the diminutive but stunning Small Copper can be added to this list.”

Dr Marc Botham, butterfly ecologist at the Centre for Ecology & Hydrology, said 2015 was a mixed year.

He said: “Much of the summer was cooler than average resulting in annual declines in many species. “Some species had a good year emphasising the complex relationship between weather and annual fluctuations in butterfly populations.”

The UKBMS relies on thousands of volunteers collecting data. Last summer 2,436 sites were monitored across the UK.

Sarah Harris, Breeding Bird Survey (BBS) national organiser at the British Trust for Ornithology, said: “It is thanks to the dedicated and enthusiastic volunteers across the UK who take part in the UKBMS scheme that we have such a clear picture of what is happening to our butterflies, both long-term and between years; without these brilliant citizen scientists we would know a great deal less. Many thanks to all those who took part and made this report possible.”