MORE than half of the UK's butterflies enjoyed their best year in a decade during 2019, official figures have revealed.

The annual UK Butterfly Monitoring Scheme led by Lulworth-based Butterfly Conservation, the UK Centre for Ecology and Hydrology, the British Trust for Ornithology and the Joint Nature Conservation Committee, compiled the data.

It showed more than half of the county's butterfly species showed higher population levels in 2019, compared with 2018 – making it the eighth best year on record out of 44 years of monitoring.

Summer flying species which benefited included the Marbled White, which had its best year in the series with annual abundance up by 66 per cent.

The Ringlet had its second best year in the series, up by 23 per cent, while the Dark Green Fritillary enjoyed its third best year with a 51 per cent rise in numbers.

Others species whose numbers bounced back included the Meadow Brown and the Lulworth Skipper. Sightings of the rare Lulworth Skipper rose by 138 per cent along the Dorset coast.

Butterfly Conservation associate director of monitoring and research Professor Tom Brereton said: “The results from the 2019 season are really encouraging and provide evidence that the overall rate of decline of butterflies is slowing and for some species being reversed. Reasons for this include positive conservation through agri-environment schemes, increased woodland cover, climate warming, increases in grazing levels by wild animals and a slowing in the rate of agricultural intensification.

“We’re really heartened to see a shift in the fortunes of many of our most loved species.

"Encouragingly a number of priority species such as Adonis Blue, Brown Hairstreak, Dingy Skipper, Large Heath, Marsh Fritillary, Silver-studded Blue, Small Blue and the Silver-spotted Skipper that have been the focus of intensive conservation efforts in recent decades by Butterfly Conservation and partners are no longer in long-term population decline.

“The long-term situation for butterflies in general does remain a cause of concern though, with more species declining than increasing since the 1970s.”

The Common Blue dropped in annual abundance by 54 per cent, Adonis Blue by 40 per cent, Green-veined White by 43 per cent and Large White by 40 per cent, with all four species having below average years.

Of particular concern is the rare Heath Fritillary, which is restricted to a tiny number of sites in southern England. This butterfly saw its annual abundance drop by 34 per cent.

This ongoing decline raises fears for the long-term future of the butterfly. Numbers of the Heath Fritillary have fallen by 91 per cent due to the cessation of traditional management practices, Butterfly Conservation experts say.

Dr Marc Botham, butterfly ecologist at the UK Centre for Ecology & Hydrology, said: “The analysis shows that numbers of a wide range of species benefited from a couple of warm summers in succession.

"In addition to record numbers of spring species such as Orange-tip and Brimstone, it was also encouraging to see annual increases in garden favourites such as Peacock and Small Tortoiseshell, both of which have had some poor years recently.

“Despite this, some wider countryside species such as Wall and Small Skipper remain at low levels compared to what they used to be.”