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

Butterfly Numbers Decline, Yet Five Species Thrive Amid Environmental Shifts

Over the past 50 years, the UK Butterfly Monitoring Scheme (UKBMS) has tracked the population trends of 59 native butterfly species, revealing a complex pattern of change. While some species have seen significant growth, others are facing steep declines, underscoring the challenges posed by habitat loss and climate shifts.

Driven by mild and sunny conditions linked to climate change, several British butterflies have benefited from the warming trend. The Red admiral, for instance, has become more prevalent, with some individuals now overwintering in the UK. Similarly, Comma butterflies, noted for their frayed wing edges, have rebounded in numbers since the survey began. The Orange tip population has risen by more than 40%, and the Black hairstreak—once rare—is showing signs of recovery due to targeted conservation work. The Large Blue, which vanished from the wild in 1979, has also improved thanks to habitat restoration efforts.

Conversely, the data highlights a troubling trend for many distinctive butterflies. A third of the species monitored have declined, with some experiencing dramatic drops. The white-letter hairstreak, whose caterpillars emit a faint glow under UV light, has fallen by 80% since 1976. The pearl-bordered fritillary, known for its striking orange-and-black pattern, has also seen a 70% reduction. Even among adaptable species, the outlook is mixed, as seen with the small tortoiseshell, which has declined by 87%.

Adaptability Shapes Survival in a Changing Climate

Experts note a growing split between species that thrive in varied environments and those reliant on specific habitats. Butterflies that can survive in farmland, gardens, or parks generally fare better, aided by warmer temperatures. These species are expanding their ranges into northern England and Scotland, as colder regions become more hospitable.

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

However, specialists—like those dependent on woodland clearings or chalk grasslands—are struggling. As these ecosystems shrink due to land-use changes, the butterflies that depend on them are unable to adapt quickly enough. Conservationists emphasize that many species rely on narrow food sources, such as primroses or willows, making them vulnerable to environmental disruptions.

The UKBMS’s extensive dataset, derived from 782,000 volunteer surveys since 1976, reflects a massive public effort. Volunteers have logged over 932,000 miles across more than 7,600 sites, providing critical insights into butterfly populations. Without this continuous record, conservation strategies would lack direction.

“Understanding where conservation efforts are making a real difference and where we need to strengthen efforts depends entirely on the quality and continuity of data that our volunteers make possible,” said Steve Wilkinson, director of the Joint Nature Conservation Committee.

Conservation initiatives focus on preserving and expanding habitats, especially as agricultural practices intensify and natural landscapes fragment. Projects like Butterfly Conservation’s Magdalen Hill Downs reserve aim to support diverse ecosystems, ensuring that species with specialized needs can persist. Yet, the survival of these butterflies hinges on maintaining the delicate balance between environmental change and habitat preservation.