Butterfly numbers are dropping but here are five species you may see more of

Five Butterflies Thriving Amidst Declining Populations

A half-century of rising temperatures and sunny conditions has benefited certain British butterfly species, according to the UK Butterfly Monitoring Scheme (UKBMS). This extensive project, active since 1976, has compiled over 44 million records from 782,000 volunteer surveys. Its data highlights both gains and losses in butterfly populations across the UK.

Of the 59 native species tracked, 33 are in steep decline, while 25 have shown improvement. One species remains uncertain due to limited data. The Red admiral, for example, has adapted to UK winters, a shift linked to warming climates. Comma butterflies, known for their frayed wing patterns, have also rebounded since the survey began.

Significant growth is seen in species like the Orange tip, which has increased by over 40% since 1976. The Black hairstreak, once among the UK’s rarest, is recovering thanks to conservation initiatives. The Large Blue, declared extinct in 1979, has made a remarkable comeback through habitat restoration efforts.

Adaptation vs. Specialization

Butterfly Conservation notes a growing divide between species that thrive in varied environments and those dependent on specific habitats. The former, including farmland and garden dwellers, are benefiting from warmer conditions and extended breeding seasons. Conversely, specialists like the white-letter hairstreak and pearl-bordered fritillary are suffering.

“Most British butterflies reach their northern range limit in the UK, so they have opportunities to expand further north into northern England and Scotland,” says Prof Jane Hill of the University of York.

Prof Hill calls the dataset “extraordinary,” crediting it as a global benchmark for wildlife monitoring. However, species tied to unique ecosystems—such as woodland clearings or chalk grasslands—are struggling. Their habitats face threats from land-use changes and environmental degradation.

Some losses are staggering. The white-letter hairstreak’s caterpillars, which emit a glow under ultraviolet light, have dropped by 80%. The pearl-bordered fritillary, whose caterpillars feed solely on violets, has declined by 70%. Even adaptable species show mixed results; the small tortoiseshell, once common, has fallen by 87%.

“Just as we have lost family-run shops and traditional skills from the nation’s high streets, we’ve lost variety and diversity in the butterfly communities that can exist in our damaged and simplified landscapes,” remarked Prof Richard Fox of Butterfly Conservation.

Volunteers have contributed to this effort by covering more than 932,000 miles across over 7,600 sites. Steve Wilkinson of the Joint Nature Conservation Committee emphasizes the importance of this data: “Without this evidence timeline, we would be flying blind.”

Conservation strategies focus on preserving and expanding habitats, especially as agricultural practices intensify and ecosystems degrade. Many species rely on narrow food sources, such as the Duke of Burgundy on primroses and cowslips or the purple emperor on goat or grey willow. Butterfly Conservation’s Magdalen Hill Downs reserve aims to create diverse habitats to support such delicate dependencies.