The large blue butterfly, once-extinct in the UK and reintroduced in 1983, flew in its greatest numbers on the largest number of sites in 2022 since records began.
Thanks to meticulous conservation management by a partnership of scientists and conservation bodies, south-west England now supports the greatest concentration of large blues known in the world.
Twelve new sites are being restored to flower-rich meadows suitable for large blue’s breeding, either ‘starting from scratch’ on arable land, failed conifer plantations and railway constructions, or by restoring bespoke grazing to degraded downland. Already, these support up to a third of the UK population of large blues, up from just seven percent in 2019.
These restorations of a disappearing type of wild meadowland have also provided ideal breeding grounds for numerous other rarities that share the large blue’s habitat.
Nikki Jeffery, executive director of the Prince of Wales’s Charitable Fund: “This project has been a great example of what sensitive habitat restoration can achieve, resulting in record new populations of the Large blue butterfly as well as the re-emergence of other rare insect and plant species.
“PWCF is delighted that our funding, in collaboration with the Royal Entomological Society and other partners, has had such a significant impact.”
Among plants, the extremely rare Pasqueflower and Cut-leaved self-heal have reappeared during management of the project.
So have up to twelve species of orchid; Musk, Fly, Bee, Green-winged, Scented, Pyramidal, Spotted, Early purple, Greater butterfly, Autumn lady’s tresses, Narrow-leaved helleborine and White helleborine.
A remarkable number of other insects have increased on the sites, while others newly colonised some of the twelve restoration spots.
These include nationally threatened species such as the Shrill carder bee, which is the UK’s second most endangered bumblebee, and the Downland villa beefly, which has not been recorded in UK for 50 years prior to 2000.
Eight Red Data-listed butterflies – Duke of Burgundy, small blue, Adonis blue, brown hairstreak, white-letter hairstreak, small heath, grizzled skipper, dingy skipper – are also thriving alongside abundant displays of more common or local insects and plants.
These restorations represent the largest and most innovative next phase of the re-establishment of the large blue in Britain.
Aside from the gains of other rare species, they are important internationally because the large blue is listed as one of Europe’s most endangered species of insect, and similarly worldwide.
Professor Jeremy Thomas, emeritus professor of Ecology, said: “The unprecedented success of this project is testimony to what large scale collaboration between conservationists, scientists and volunteers can achieve.